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

[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!



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:



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?




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.