Project Allroad -- Engine Doesn't Start -- Zero Compression Cyl 4/6

[chillax]

I'm not sure if this is the correct forum, so mods, feel free to correct me if I am in the wrong.

I recently bought a 2004 Allroad 2.5L TDI (engine code BAU) with 180k km on the clock. It didn't run, but they assured me there was no engine damage... I assumed it was the common injector pump failure.

I got it home to my garage and started my diagnosis:

- Looks like the fuel filter was recently replaced and there was no fuel leaking out of the lines when I disconnected them. It looks like the entire line from the filter to the injector pump is dry.
- I quickly did a compression test and was a bit disappointed when I saw no compression on cylinders 4&6 (driver's side bank). I am going to do another test again tomorrow to make sure I didn't get a bad reading.
- I haven't yet put it into 'service position' to check on the timing belt status but I assume it will need to be replaced soon.

I'm not sure exactly what my next steps are and am looking for suggestions/tips.

Before I take off the head and inspect the valves for damage, I want to see whether the fuel pump pumps. If the line is empty between the filter and the IP, should I just use a small container of fresh diesel and see if it sucks it in? Is there a better diagnosis I can do for the IP?

It is possible that the car stood for about a year and I saw in some other threads, people suggested moisture could have entered the cylinders and rusted up the valves making them difficult to seat. Could that lead to 0 compression?

I don't mind redoing the heads if there is a bent valve... my concern is more whether this could be a more serious block issue and whether I should try to find a replacement engine? With the newer BAU engine, is camshaft wear still as big a problem as it was in the AKE generation? If it turns out to be a bent valve, should I get the whole new camshafts, followers and rollers or just replace the bent valves and followers?

Any suggestions on where to go from here?

Cheers, chillax

[zollaf]

whats the compression on the other cylinders ?

[chillax]

whats the compression on the other cylinders ?

~25-26 bar

[zollaf]

unlikely to be a timing belt then. you could remove a cam cover and look at the lifter, see if its low or anything, but could just as likely be a stuck valve, rusty seat or rusty ring. thats the sort of thing that would hopefully cure itself when it up and running. to start with i would be tempted to remove all the glow plugs and pour diesel into all the cylinders. leave it a few days, spin it over to blow any diesel still in there out, then pour a bit of engine oil in. then spin it over, replace the glow plugs, turn it a few times by hand to make sure it isn't going to hydraulic, chnage the engine oil thats now full of diesel, and see what happens.

[chillax]

Ok, I'll give that a go. Thanks.

Any ideas about verifying the IP state?
Do I need to prime the fuel lines in a specific manner? Mityvac the return?

[zollaf]

yeah, a bugger to prime. a small hand primer, a squeezy one might help. or vacuum the return..

[ametlib]

Hi, just noticed this tread. If the Injection pump makes a buzzing sound for a second or so when you turn the ignition on, it's at least 95 % chance the pump is ok. About the rest I would have looked behind the upper front covers.
I wouldn't be too surprized if you find a brand new cambelt there

[chillax]

Thanks for the tips guys... I got a bit further, but now have other strange issues.

So, I came at this from a fuel perspective

- I vacuumed the inlet of the fuel filter and the fuel came pretty quickly... didn't seem like there was a major blockage
- I vacuumed the inlet to the parking heater and fuel came very slowly (this is after the IP on the way to the return). Lots of resistance and air bubbles--but could have been my hose setup. While I was doing that, fuel was moving very slowly through the clear tubing to the IP... don't know if that's normal.
- I then cracked open the injector nuts and tried cranking... very, very little came out.
- I noticed a small buzz for a second or two when I turned on ignition (assumed that was the IP as per ametlib's suggestion)
- Then I hooked up the vagcom and ran the fuel pump test (Engine -> Basic Settings -> 035) which was supposed to turn the fuel sender pump on for 30 seconds. I could hear it buzzing in the backseat, but then I heard a lot of gurgling coming from near rear passenger door... nothing leaking, but strange gurgling. Thinking it could be an empty tank, but the fuel gauge indicates about ~1/3 of tank and no low fuel warning. FIS indicates 200km left on tank. I also didn't clamp down the incoming line to the fuel filter, so I expected some fuel to leak out from the sender pump pressure (I read it should output 0.5 bar fuel pressure).

So, my signs point to bad fuel sender pump--but why would it make buzzing sound? Are there any connections between it and the filter?

Any other ideas?

I am going to try to get access to the sender pump tomorrow after work.

Cheers!

[ametlib]

I got a bit further Meaning the compression issue is solved ?
The pump in the tank only moves fuel internally in the tank and as long as you hear it the chances all is ok is around 99,99 %. The buzzing from the IP is coming from the quantity adj. in the rear of the pump, probably the pump ecd is running a check, anyway
the sound means the pump is likely to be ok.
Putting vauum to the inlet of the parking heater makes no sence, you have to pull fuel through a high pressure pump, am surprized you got fuel coming out there at all.

[chillax]

No, compression issue is not yet solved... I thought if I could diagnose the fuel issue, I could try to get it started and if there was just some light rust on the valves/seats, it could clear itself up.

Yeah, I wasn't sure about vacuuming the parking heater line, but I thought it was being fed from the return of the IP and I could bleed the IP in this method.

Where should I vacuum to make sure fuel is getting to the IP? The inlet at the bottom of the pump seems very difficult to access.
How much fuel should be ejected through the cracking of the injector connectors?

And to confirm -- turning on the tank fuel pump shouldn't push any fuel to filter?

[Peter D]

I can send you the diagrams of how to bleed it. There were two fuel system one up to vehicle ID 4B_2_109430 and a later type from 4B_2_109431 onwards. PM me your email address. Regards Peter

[chillax]

Thanks... PM sent

[ametlib]

if there was just some light rust on the valves/seats, it could clear itself up. No - that would never in a million year give you a compression reading of 0.


And to confirm -- turning on the tank fuel pump shouldn't push any fuel to filter? Correct



Where should I vacuum to make sure fuel is getting to the IP? Pull one of the bleed off pipes wich is connected to the return on the injection pump, vacuum there .However I suggest you first of all check the cambelt. A brand new belt indicates
the old belt jumped or snapped, meaning you have to pull left side cyl. head ......

[chillax]

Thanks ametlib

I will run the compression test again (probably tomorrow night) and try to confirm the results.

What would give 0 reading on two cylinders? Bent valves? We tried to determine which valves could have been down on 4&6 based on the firing and there is a possibility that they were down (4 in exhaust and 6 in intake phase). I looked at the timing belt on the right bank and it didn't look new. I haven't gotten the cover off the left side yet... but any dead giveaways to look out for? It may have been sitting in a dusty location for a while. Would all timing belts have some printing on the back?

I don't have the equipment to do a full leak down test... so I feel like the next step would be to remove the left head and inspect the valves and the pistons themselves. What would the chances be of a problem in the block itself to give non adjacent cylinders 0 compression? (my guess -- and hope --- is very little)

[adamss24]

Before you jump to conclusions i would remove the driver side rocker cover and check the lifters are moving when you spin the engine by hand... If the engine is spinning without locking then chances are the heads are good however the BAU engine has hollow cams on which the cam lobes break allowing the valves to stay shut hence no compression...

[chillax]

Wow... that's good to know. Ok, I will check and report back.

Thanks *fingers crossed*

[ametlib]

Before you jump to conclusions i would remove the driver side rocker cover and check the lifters are moving when you spin the engine by hand... If the engine is spinning without locking then chances are the heads are good however the BAU engine has hollow cams on which the cam lobes break allowing the valves to stay shut hence no compression...

Possible yes, but that means both left side cams have 2 loose inlet lobes each, also 4 loose lobes... I might be wrong but I put my penny on bent valves. Nethertheless pulling the left side rocker cover is a good place to start

[adamss24]

Possible yes, but that means both left side cams have 2 loose inlet lobes each, also 4 loose lobes... I might be wrong but I put my penny on bent valves. Nethertheless pulling the left side rocker cover is a good place to start
Bent valves will make a PING noise when you spin the engine by hand as they usually bend at the cotter end, however every B** type engine i have worked on with bent valves also had wrecked heads- the cam rollers don't break as on early engines so they are not sacrificial and thus saving the engine ! Most likely the cam rings are snapped- had many like this however they were BDG/BDH engines which hydrolocked due to water/coolant ingress from the water cooled EGR or timing belt break...

[chillax]

So, I got the cam covers off finally... what a PITA that was. Do you typically remove the coolant tank to get access? Do you remove all the fuel pipes from the IP? What tool do you use to do that? I could get two of the nuts loose using my 17mm box wrench, but couldn't easily access the other four.

When I got the covers off, I couldn't see anything that looked like it was broken... no shards of metal... but I didn't yet rotate the cams because I was alone and the car was not in 'service position' so I had no access to the main crank. I will turn it over tonight and report back.

Bit of buildup of carbon on the middle intake -- haven't yet taken of the left or right intakes. Would you recommend oven cleaner to de-carbon them? Or what's the latest wisdom on this?

[ametlib]

Do you typically remove the coolant tank to get access?

No, you can take off the el-connector in the bottom and bend it forwards against the abs .


Do you remove all the fuel pipes from the IP? What tool do you use to do that?

Yes with an open spanner.


Would you recommend oven cleaner to de-carbon them?Not really, it's a bloody mess. I was planning to try the battery charger rust remover trick next time I needed to decarbonize a manifold. Bucket of water, add a few spoons of salt and connect the charger - to the manifold and the charger + to a piece of iron / steel ( not stainless, it will make toxic gas) in the bucket. Have no idea if it works on carbon deposits but it's great for removing rust .

[chillax]

Not really, it's a bloody mess. I was planning to try the battery charger rust remover trick next time I needed to decarbonize a manifold. Bucket of water, add a few spoons of salt and connect the charger - to the manifold and the charger + to a piece of iron / steel ( not stainless, it will make toxic gas) in the bucket. Have no idea if it works on carbon deposits but it's great for removing rust.


Hmmm... never heard of using electrolysis for decarbonization. It makes sense for rust removal (iron oxide) and the induced electric field will pull the iron out with it. Does the same work for carbon? Please send me more info on this as I would be very interested in using it. I would also recommend to use baking soda instead of your salt (NaCl) as it could release chlorine gas (Cl2) which is also deadly.

Thanks for the other tips.

[ametlib]

Have no clue if electrolysis will remove carbon and I've never heard about it beeing done eighter. I used this methode to remove rust of 2 brake calipers that was partly rusted and partly painted in a dreadful red color. What happened was not only the rust
disapperad but the color too !! Made me think about carbone ....
Yes you're right about baking soda but salt works better ... :)

[chillax]

UPDATE

Ok... so I reran the compression tests and they came out just as before. Right bank is in good shape (24-27)bar, but Left bank has 0-27-0.

I also went fishing with my magnet and caught me a rocker!

http://i.imgur.com/EJEcoInl.jpg

So... I couldn't tell which cylinder that came from, but I found most of it near the base of the middle cylinder... I guess the head will come off next and my question is how should I proceed? Should I just dismantle the head and replace the camshafts and the rockers/followers/valves of the affected cylinders or should I do the whole thing? And if I do the entire left bank, should I do the right bank while I am at it?

Next what kit should I get or stay away from? I was reading in one of the german forums that Eksan brand was one to avoid and possibly CAMPRO as well?? Who is Audi using as OEM? Kolbenschmidt? I assume I should also stay with BAU specific parts and not go back to AKE components?

Is there any way to confirm that the IP is working sufficiently before I take off the head(s) and belt?

Anything else I should be wary of or test before proceeding?

Cheers!

[ametlib]

or should I do the whole thing?

Why replace things that aint broken ? Since you now have the rocker covers off you can see what's broken and what's ok. Any loose cam lobes ? any more rockers missing ? Give me the overview and I'll tell you what I would have done.

Audi OEM cams are Ruville but I think Kolbenschmidt cams and INA rockers/ pushers are of the same quality

[chillax]

I am going to remove the bumper and get complete access to the belt and left head. I will then turn the crank manually and see if the cam lobes are turning. If they are, would you replace the shafts to be safe? Then I can see if any more rockers are missing.

I'll let you know what I find...

[chillax]

Ok, so more disassembly and more confusion.

After getting the car into service position, getting the cam covers off and cranking the engine by hand, it seems there is a definite problem with the driver side bank:

http://i.imgur.com/IZhH9uI.jpg

It might be hard to tell, but it seems that both shafts were installed (or somehow ended up) not being mirrors of one another, but rather, 180 degrees off. ?!?!?!? I don't even know how someone could install the head like this since you would have to rotate the cams to access the bolts. I am not sure how this could happen... the teeth on the gears don't appear to be stripped, but I haven't pulled the head off yet, so I am not sure what I will find. Any ideas?

I wanted to get the crank and the passenger side bank into a known location (ideally, tdc) so that when I take the belt off and remove, rebuild and reinstall the left head, I would just have to do its timing and the injector pump's timing and be all set.

I've been trying to follow the guides for finding TDC, but things aren't adding up.

- Tried to access the viewport on the crankcase, but can't seem to access it yet (any special tools recommended here?) I disconnected the AC compressor and tried using a 1/4inch ratchet on the bolt and was afraid I would break the tool and my 1/2" extension is too long. I am going to try a 3/8" set tonight... but so far, haven't been able to get to the portal
- Cranked the engine manually until the right bank's head bolts were accessible and I could insert the locking key. Then I inserted a small wire into what I think is Cylinder 1 (front-most cylinder on passenger side -- the one closest to the bumper).. but when I cranked on the crankshaft, it was clearly not at the top of compression. I had to crank the engine about 60 degrees until it felt like the piston was at the top of its stroke. Also, while the cams were locked, it seemed that cylinder 3 (closest to the passenger compartment) was at TDC power stroke as both sets of lobes were pointing skyward. Where should the lobes be pointed on cyl 1 when the camshafts are lockable/head bolts accessible?
- Also looked at the little nub on the crankshaft and it was pointing more towards ~-45 degrees from top. Does it have any relationship to TDC? Or just for aligning the bigger serpentine pulley?

http://atlib.ru/Templates/storage/blog/73/163339_121.jpg


I would like to establish a baseline from which other assumptions can be built, but I can't seem to find a solid piece on which to stand. Would prefer to establish a safe and known point of the engine so that I can just focus on the bad head.

Any suggestions? Thanks

[ametlib]

Ugh!! At least you can forget about loose cam lobes because you have 3rd gen cams wich are solid and damn good too ! Have a terrible headache so I'll post more tomorrow, sorry

[ametlib]

So, what did happen here ? Could one of the crimped on gears in front of the camshafts have loosened ? If so, why? According to the other bank there have not been an belt snap or belt jump, it's still in one piece and compression is fine .
The crimped on gears still needs to be checked out though.
Makes me wonder if someone changed the camshafts on only one side and messed up big ?
Anyway the faulty head have to come off for further inspection as I'm pretty sure you have some bent valves down there. Its a tight squeeze ( especially since you have the worste side) but it's doable.
The TDC is found in the crank itself. Its a drilled hole you lock aganst a similar hole in the cyl. block , cars right side, a couple of inches in front of the clutch housing, placed low so it have to be accest from underneath.
Just drain the coolant and pull the head and take care to undo the bolts in correct order. ( these heads can become warped even if they are short)

[niall campbell]

I would take head off & send for stem guides / valves / skim etc They will realign everything

My boys Polo was £110 for this same job.

I would also pour a bit of petrol into each cylinder and see if it drains overnight, just to check the piston rings

[chillax]

The TDC is found in the crank itself. Its a drilled hole you lock aganst a similar hole in the cyl. block , cars right side, a couple of inches in front of the clutch housing, placed low so it have to be accest from underneath.

Thank you for your comments. Yes, once the head comes all the way off, it will be more accessible to determine what happened.

When the engine is in TDC, does that mean that the heads should also be in the lockable position with the head bolts accessible? The question is more for later when I put the head(s) back on to ensure that there is no impingement likely and that everything is properly synchronized.

I am also leaning towards someone getting in there and doing a 'bang'-up job on at least the one head--though how they would be able to bolt on the head with no access to one row of head bolts at a time seems strange.

I'll update again when the head is off.

[chillax]

I would also pour a bit of petrol into each cylinder and see if it drains overnight, just to check the piston rings

How much petrol would you expect to drain off? Is any loss acceptable? ie, should I pour in a measured amount and measure the amount left over after a day? Or if there is a problem, will all the petrol have drained?

[ametlib]

When the engine is in TDC, does that mean that the heads should also be in the lockable position with the head bolts accessible?

Yes when the engine is locked at TDC all 4 of the camshafts can be locked with plates in the milled slotts in their rear end, all the cyl. head bolts can be accessed through the slots in the camshafts and the piston nr. 3 is on TDC.

[chillax]

Yes when the engine is locked at TDC all 4 of the camshafts can be locked with plates in the milled slotts in their rear end, all the cyl. head bolts can be accessed through the slots in the camshafts and the piston nr. 3 is on TDC.

Perfect! That cyl 3 is on TDC when the engine is properly locked was the key we were missing! Thank you very much for that piece of the puzzle. That's what we observed, but couldn't figure out why Cyl 1 valves and position did not correspond to actual TDC. Thank you for that.

[ametlib]

You're velcome. Will strongly advice to get hold of a workshop manual or something ELSe usAbel for WINdows. Maybe if you search on a internet marketplace ? There are lot of small nuts used in these heads and they really don't like to be overtightned.
When you start to put things back together, use the torque wrench on every one of them

[chillax]

You're velcome. Will strongly advice to get hold of a workshop manual or something ELSe usAbel for WINdows. Maybe if you search on a internet marketplace ? There are lot of small nuts used in these heads and they really don't like to be overtightned.
When you start to put things back together, use the torque wrench on every one of them


I was able to get a hold of that useful WINdows toolbook. I was just surprised at the lack of some information found within (ie, when engine is in locked position, cyl 3 is in TDC). I have all the torque values and will be using that when I put it all back together.

It seems only the exhaust side of the camshaft gears have the backlash support... how can I tell if the camshaft is reusable or in need of replacement? I'll take more photos when I get the head totally off.

[ametlib]

Hmm, some of the workshop manuals for Audi seems to offer a lot more information in the A4 section than in the A6 section

[niall campbell]

Petrol will as we know evaporate

Even a bit of diesel.

I would put enough in that it covers the piston head & no more. You will see if its leaked, its not really scientific

[ametlib]

Petrol will as we know evaporate

Even a bit of diesel.

I would put enough in that it covers the piston head & no more. You will see if its leaked, its not really scientific


As you say- not scientific but good thing is the bottom of these engines are very reliable and if there is no scratch in the cylinders it's probably ok

[niall campbell]

not always.

My boys Polo never had any scratches , it was the oil rings that were away in his car, with no blue smoke .............................. stumped myself for ages. However the Polo seems infamous for it, not so with this car

[chillax]

Removed the exhaust side cam and found two issues:

http://i.imgur.com/G7mesUB.jpg

and the second:

http://i.imgur.com/LvYA7yX.jpg

So I assume this camshaft is shot... or can new lobes be reseated?

I'm still working to release all the exhaust manifold bolts so that I can remove the head and will then remove the other shaft and look for similar issues. Only the one broken roller was found (as posted earlier in the thread) and it corresponded to the middle cylinder (with good compression) and the lobe that had rotated (with air gap in photo).

Do you normally access exhaust and catalytic flange bolts from underneath the car or can you do it from up top?

[ametlib]

Since you have hollow cams ( and I probably need new glasses :) ) take out the other cam first, then use a piece of wood ( little hammer with thin wooden shaft is perfect) and push the valve down one by one.
If a valve is bent it sounds different when you let it back in it's seat.
If you go forward with pulling the head, it's a pain in the butt to undo the manifold. I use to take the 3 bolts between the manifold and the flexpipe going to the turbo from the top ( but it,s a lot of swearing involved :) )

[chillax]

Ok! I got the head off... wheww.. lots of things to disconnect.

So, the pistons look ok to me. There is a bit of cross-hatching on the cyl walls, but I am not sure if that's anything to be worried about.

http://i.imgur.com/XWD71O1.jpg

cyl 4:
http://i.imgur.com/UgGMWj0.jpg

cyl 6:
http://i.imgur.com/ZLJJX2i.jpg

My plan now is to clean the head and carefully document where each piece goes. I will take off the other cam shaft and make sure it isn't broken either. I will probably pull the valves and make sure they are true... I will upload another picture after I have removed the loose pieces... they appear to seat flush--at least no obvious bends or breaks.

Couple of questions:

- what should I use to clean off the old head gasket residue?
- I've looked on ebay.de and ebay.co.uk for camshafts and have only found them as sets and they look like they are forged (even if they say the are for the BAU engine). Where should I get them? From Audi/VW/Skoda directly? Should I buy a whole kit like this: Nockenwellen Satz für 2,5 TDI V6 VW AUDI SKODA BDG BAU BDH BCZ | eBay (http://www.ebay.de/itm/Nockenwellen-Satz-fur-2-5-TDI-V6-VW-AUDI-SKODA-BDG-BAU-BDH-BCZ-/231568983019?hash=item35ea9643eb:g:hfYAAOSwx-9WxD68) ?

Anything else I should do while the head is off?

Thanks for the help so far... can't wait to hear it run again!

[rowdy-999]

Good work.
Isn't the cross hatching a result of the original honing, so a good thing?

[Rob69]

I can't see your pics of the cross hatching maybe cos i'm on a train, but crosshatch will be from original machining like rowdy says, and that is ok, look out for vertical scoring, or hot spots, excessive ridge at the top of the cylinder from the top piston ring etc. Piston crowns look pretty much the same or does any one stand out as heavily carboned up?

[chillax]

Good work.
Isn't the cross hatching a result of the original honing, so a good thing?

Yeah, I think it is a result of the honing... whether original or not is unclear.

It's just one more clue in the mystery that is why this car wasn't running when I bought it.

I am trying to put together a theory as to what would cause this set of events.

I know the previous owner must have discovered a problem with the engine... someone got in there to play with that bank of cylinders (4-6). Someone also reinstalled the exhaust side cam 180 deg incorrectly. Whether the engine had compression before then or not is unclear. My current theory is that a single camshaft lobe or hydraulic lifter failed. That caused him to get in there... but he wasn't sure what he was doing. Putting the cam in incorrectly caused more damage when it was turned with the starter. I found all 6 glowplugs had been replaced and the injectors on cyls 4&6 looked brand new.

Anyway, I guess we figured that the hatching would have worn away over 180k km and so it made us think that the cylinders may have been re-honed as well??

[chillax]

look out for vertical scoring, or hot spots, excessive ridge at the top of the cylinder from the top piston ring etc. Piston crowns look pretty much the same or does any one stand out as heavily carboned up?

No signs of vertical scoring, but there are some strange marks (about the size of a quarter @ 7:30 o'clock)
http://i.imgur.com/ZLJJX2i.jpg

No noticeable ridge where the piston ring stops and no difference between the crowns.

Going to post some more photos of the head in a moment...

[chillax]

Head pictures:

http://i.imgur.com/pqOF2DV.jpg
http://i.imgur.com/3kVZTe6.jpg
http://i.imgur.com/4QjxTVT.jpg
http://i.imgur.com/uzl4J8d.jpg

Intake cam looks fine:

http://i.imgur.com/A0R8XX0.jpg
http://i.imgur.com/Eu93Cyo.jpg
http://i.imgur.com/GbjArtP.jpg
http://i.imgur.com/9CIhiTx.jpg
http://i.imgur.com/PEJ3QYu.jpg
http://i.imgur.com/CW2Xvlf.jpg

[ametlib]

So far, good job ! Don't worry about the honing, it's 99 % sure it's from the factory. ( I once opened a engine with 510 K km on the clock and the cylinders still looked like yours ! )
A camshaft kit with roller rockers is rather expensive, have you concidered a used head from ebay de. ?

[ametlib]

have you concidered a used head from ebay de. ?

Probably not :) just for fun I looked on ebay and couldn't find a single head with roller rockers.. Only thing I found was used hollow cams, costing around 110 eur each . Audi A6 (4B) Avant 2,5 TDI 120KW Bj.11.03 BDG Nockenwelle Links

[chillax]

Amazing that the metal wouldn't wear down more...

I have considered a used head, but most don't seem to come with the camshafts and the ones that do seem to come with the AKE-generation cams. I'll do a bit more searching...

[chillax]

Would you mix and match construction styles of cams?

I could buy this cam: NEU!Nockenwelle AUDI Super B 2.5TDi 163PS-180PS 059109009BJ 059109102CP BDH BDG | eBay (http://www.ebay.de/itm/NEU-Nockenwelle-AUDI-Super-B-2-5TDi-163PS-180PS-059109009BJ-059109102CP-BDH-BDG-/321831495724?hash=item4aeea6e82c:g:MJkAAOSwhcJWQL-W)

but he doesn't look like hollow-style... more forged with lobes attached.

Not sure of the quality... :/

[ametlib]

Hm it's your money. The cam in question is cast iron , nothing attached, have no idea about quality. I usually do it cheap or good, nothing in between. Cheap I would have ordered the used hollow cam of ebay and a couple of rockers, If good I would go for a kit of solid cams of steel

[chillax]

Ok, great... I have found a couple... and I want to go with 'good' not necessarily cheap.

While I have half the engine apart, is there anything else I should look for or replace? I am definitely going to replace all the belts and the water pump. I will renew gaskets and I also removed the turbo while trying to get the head off (unnecessary, but gave me more room to work around the head and exhaust)... so I will clean it while it's out.

Anything else that will save me from having to get back in there for a while?

[ametlib]

Anything else that will save me from having to get back in there for a while?

Some would say the oil retention valves, I would just leave them along and change the thermostat instead. Other than that maybe a good idea to check the oil return tube from the turbo when it's off anyway, it sometime chokes up.

[rowdy-999]

Anyway, I guess we figured that the hatching would have worn away over 180k km and so it made us think that the cylinders may have been re-honed as well??

A good, well made engine which has been serviced well, will have the original cross hatching, even at that mileage.
I rebuilt a very hard driven Nissan SR20DE a few years back @100k miles which still had factory fresh looking cylinder bores.

[zollaf]

my 80 still had it at 305,000 miles, protected by a nice layer of glass like glaze.

[chillax]

Would you replace the camshaft bearings or are they good if they don't show any signs of abuse?

Sent from my SM-G928F using Tapatalk

[chillax]

How seated should the valve guides be? I removed a couple of the valves (intake valves very caked in carbon) and saw the valve guides sticking out farther than I would have thought. Is this normal?

http://i.imgur.com/litIVim.jpg


http://i.imgur.com/1wKmqdA.jpg

I didn't take any pictures from the other side, but it also looked like the guides could have gone down farther.

I took out 1 intake valve from cyl 5 & cyl 6 and 1 exhaust valve from cyl 6 and all the guides looked to be at the same height.

Any reason for concern?

[ametlib]

Any reason for concern?

I think no. Just install the valve vithout the springs and measure that there is room for the valve to open fully without the top spring cap smashes into the oilseal ontop of the guide. I have changed the guides on these heads a few times and one
thing's for sure, these guides won't loosen by themselves .... In order to get them out you have to drill half of them away, then use an air hammer to knock them out. To get new ones in they have to come right out of the freezer and drive them in with the air hammer.
The fit is so tight that the inner diameter changes when they are in place ....

[chillax]

It's been a long time since the last post, but a lot of work has gone on behind the scenes.

I put in the new camshaft and timed the engine. While trying to get the tension on the timing belt, I discovered what I thought may have been the smoking gun:

http://i.imgur.com/JP5jxfc.jpg

It looks like whoever installed it last didn't do it correctly and then tension roller rubbed into this arm. Perhaps the old belt detensioned and slipped and caused the initial cam damage? I replaced it and then finished the timing and tensioning of injector pump belt.

I turned the engine multiple times manually to ensure I didn't encounter and valve interference and then tested compression: 21 and 22 all the way up to 24 across all the cylinders!

Next -- the moment of truth. Trying to start it for real. No go... :( It cranked and cranked, but wouldn't catch.

After that, I started diagnosing further...
- took out each glow plug and connected them directly to the battery to verify they were still good
- cracked the injector lines and saw fuel spilling out when cranking.
- smelled the exhaust pipes for any hints of diesel smell... hardly any (I would think suspicious??) some light puffs of air coming out the tail pipes
- opened up the ECU housing and discovered two things:
- It is outfitted with an ABT ecu
- The relay '395' was bent with only two pins in their holes and the other three disconnected. I reconnected it but the car still wouldn't start.

http://i.imgur.com/LWBaeuW.jpg
http://i.imgur.com/w6TZWOU.jpg

So, I'm not sure what my next steps should be. Reading through all the posts here leads me to think that my problem is a bad injector pump, but I don't know how to diagnose that. It's pumping fuel into normal ~1 bar of outside pressure, but don't know if it can pump into 22 bar of cylinder pressure?? I wouldn't think that all 6 injectors are bad... if only 1 or 2 were bad, I would think it would start or almost start and then run roughly -- or?

What would you suggest to test next? Could the ECU be bad? How could I diagnose that? Would it be able to speak to the vagcom if it were dead or bad?

Thanks for all your help so far --- can't wait to get this beauty back on the road!

[ametlib]

I'm in a hurry for now but i'll be back tonight, be 100 % sure the pump is properly bleed !

[chillax]

I took the vagcom to the car and got the following errors:

VIN: WAUZZZ4B84N082465 Mileage: 183510km-114027miles
-------------------------------------------------------------------------------
Address 01: Engine Labels: 059-907-401-AKE.clb
Part No: 8E0 907 401 J
Component: 2.5l/VTEDC G000SG 0006
Coding: 06008
Shop #: WSC 02335
VCID: 2C5CB100DC9BDE5EF2-4B00

Subsystem 1 - Part No: 00006059
Component: 130 106LC150_1.V79096372482
WAUZZZ4B84N082465 AUZ7Z0C2520227

5 Faults Found:
00523 - Intake Air Temp Sensor (G42)
30-00 - Open or Short to Plus
01282 - Intake Manifold Flap change-over Valve (N239)
35-10 - - - Intermittent
17569 - Manifold Temp Sensor (G72)
P1161 - 35-00 - Open or Short to Plus
00522 - Engine Coolant Temperature Sensor (G62)
30-00 - Open or Short to Plus
00519 - Intake Manifold Pressure Sensor (G71)
31-00 - Open or Short to Ground
Readiness: 1 5 0 X X

// Regarding the faults, the engine is without coolant at the moment and intake sensors aren't connected -- so nothing is jumping out at me as being very unusual

I then queried the Engine (block 01) and got this:

http://i.imgur.com/V8fSJTw.png

I tried to query the Diesel Pump (block 41), but it couldn't read from the controller:

http://i.imgur.com/LwyGSv6.png

What can I do to make sure that IP is responding?

Finally, I sprayed some EasyStart into the intakes and tried to crank it... it fired to life for a second or so and then died.

I am going to try to rebleed the fuel system and see if that helps. I will also test the relays (395 and 219) to make sure they are still good. What else should I check to make sure that the IP and the ECU are either working or not?

[ametlib]

First connect everything as in all sensors, if you pull the MAF wire and one of the others at the same time it can be very hard to start. Next, when you turn the ignition on the Injection pump shall make a buzzing sound for a second or so, if it does so bleed, bleed and
when you've done that bleed some more :) If still no start gravity feed the pump from a bottle or fit an pump between the filter and IP and bleed again. When you try to crank it you open two of the injector pipes. If there is no sound coming from the IP when you turn the ign. on
you need to check if there are voltage coming to the ECU and pump, just check it with Vag com

[chillax]

First connect everything as in all sensors, if you pull the MAF wire and one of the others at the same time it can be very hard to start. Next, when you turn the ignition on the Injection pump shall make a buzzing sound for a second or so, if it does so bleed, bleed and
when you've done that bleed some more :) If still no start gravity feed the pump from a bottle or fit an pump between the filter and IP and bleed again. When you try to crank it you open two of the injector pipes. If there is no sound coming from the IP when you turn the ign. on
you need to check if there are voltage coming to the ECU and pump, just check it with Vag com
Great, thanks... Will connect everything, bleed and try again.

Where in vcds can I check voltage coming to ecu and IP?

Sent from my SM-G928F using Tapatalk

[ametlib]

Where in vcds can I check voltage coming to ecu and IP?

Measuring block 18 or maybe 16 dont remember so you need to check it up, you. Any buzzing sound coming from the Injection Pump ?

[chillax]

Alrighty... I measured the blocks and found these two screens of interest:

http://i.imgur.com/uWyfa6j.png

http://i.imgur.com/KULErGj.png

Does this look like the IP should be working? The IP does buzz for a second or so just after ignition turned on. Does the buzz indicate successful startup or insufficient fuel or something else?

I used the bleeding method suggested by ElWin (using a remote switch to drive the fuel pump in the back seat) and it definitely pumped fuel--but at a very low rate. Is that normal? I could see bubbles being pushed through the line, but after a while it seemed like either it wasn't pushing enough fuel to remove all the air in the clear tubing between the filter and the IP or it was sucking air in from the rear. How much fuel should it be pumping? I tried starting it after reattaching the MAF sensor, and it sounded like it was trying to catch for a second or so... but then just went back to the turning.

[chillax]

More diagnosis....

I decided to bypass rear fuel sender by taking a jar of diesel and vac'ing it through the IP from the line that would feed the inlet of the fuel heat exchange. I had a nice column of fuel ready to feed the IP. Hooked up all the sensors and had 0 engine code faults. Measured 160-180 RPM while cranking. Still no start. :(

I then cracked two injector lines (cyl 4 & 5) and placed a paper towel between the pipe and the injector... cranked and there was fuel on the paper... but I had expected it to tear or pierce due to the high pressure the pump should be outputting. I am beginning to the think that the IP is the problem. Any way to definitely tell?

Thanks,
chillax

[ametlib]

cranked and there was fuel on the paper.
Only pressure from the internal vane pump, the high pressure part can still be bone dry. This time you have no fault codes so I suggest you gravity feed or pressure feed the injection pump to bleed it ( even if it can be faulty without throwing a code )
When it comes to bleeding its my opinion the VP 44 is one of a kind, who ever invented the P.O.C. he should have been &%¤(& :) The pump in the tank only moves fuel internally, the Injection pump sucks trhe fuel forward from the tank

[chillax]

suggest you gravity feed or pressure feed the injection pump to bleed it

I used the jar of diesel and some clear PVC tubing to feed the IP directly. I vacuumed the return to ensure that there was a column of fuel over the IP inlet.

The lift pump was completely out of the picture. Wouldn't vacuum be better than a gravity feed?

How would I know I am on the right path? When the IP is properly bled, would my hypothesis of violent fuel ejection be correct? What is the failure mode of a pump who can't make the necessary pressure?

Thanks

[ametlib]

The buzzing sound you hear from the pump when you turn the ign. on is some kind of test procedure the pump performs and the sound is coming from the quantitry adj. No the thing is- I have never seen a faulty pump wich both runs this test and at the same time do
not throw a faultcode ......Meaning I still doubt there is something wrong with the pump ( but by all means I can ofcourse be wrong ) how about timing of the pump ? Also check the MB. 18 engine speed sensor ( isnt that to many 1ns ? ) Last you have to crank with 2 injector
pipes open until the engine starts ..... Otherwise you can crank all day no matter how much you bleed by vaacuming the pump return

[chillax]

IT STARTED!!!!

I got it started after finally giving in and ordering a refurbished pump from Stefan @ Autoteile Unseld. Came very fast and I was able to install it, pair it with the immobilizer and then bleed it again. Bleeding was a snap compared to the old pump... fired up after a couple cranks!!

Thank you all for your help. I'm sure I will be asking more questions, but right now, I can't wait to get it all reassembled and out on the road!

Thanks again

-Chillax