slow cranking starter after rebuild

[kaisersolsay]

Hi guys,

Just finished a rebuild on my brothers 2001 1.8T A4. He had bent the exhaust values.

When trying to start her up I notice that the starter is turning really slowly despite the battery being freshly charged. I've even tried it with jump leads but still very slow. It doesn't give the normal 'car turning over trying to start noise' either, instead it just sounds like its slowly spinning the crank and pistons round....which its obviously doing. I have checked the plugs and they are sparking and wet with fuel.

Have I wired the starter back up correctly? There are 2 thick wires, a red and a black. From what I remember one is from the battery (red) and the other from the alternator (black) and they both bolt onto the same place secured with the 13mm bolt. The smaller red connector then pushes onto the tab beneath.

During cranking on one occasion there was a slight puff of smoke that came from the starter location?????!!

I can only think I have the wires in the wrong place.

Anyone remember how to wire it up??!

[kenney]

I don't think it's possible to wire the starter wrongly,i think maybe you have a poor earth somewhere

[kaisersolsay]

Ok, I'll check. Just to be sure, there are only 3 wired connections right? Alternator (Black) Battery Live (red) Trigger Live (small red) Where is the earth?

[kenney]

That is correct There are 2 main earth wires, from the battery to the chassis,and the other from the chassis to the engine

[kaisersolsay]

Is there an earth from the starter?

[kenney]

No,I think you will find the engine- chassis earth is on one of the gearbox screws.The starter is earthed by way of the block.What might be a good idea since you have had the engine apart,is to make sure it turns easy by hand

[kaisersolsay]

Great thanks. There is a black cable with a mounting bracket floating around the
back on the block resting on the gearbox. I was just being lazy and hadn't secured it.
Could this be the main chassis-engine earth?

[kenney]

possible

[kaisersolsay]

OK, I've secured the rear bracket but unfortunately the starter is still cranking over very slowly.

Anyone got any other ideas?

[kenney]

Still think you have a poor earth somewhere,if the starter was ok before the overhauling,and does the engine turn easy by hand?

[Crasher]

Your thinking the same as me Kenney, tight cams.

[kenney]

Your thinking the same as me Kenney, tight cams.Great minds think alike and fools seldom differhttp://www.vwaudiforum.co.uk/forum/images/icons/icon7.gif

[Crasher]

:D.

[kaisersolsay]

Nothing wrong with the cams lads, its the starter and I think the wiring is not correct.

See diagram below;

http://i182.photobucket.com/albums/x309/kaiser_solsay/earthzy.jpg[/IMG]

Where does this lead that I have circled in red connect?

I currently have this lead (has red coloured collar) and another black lead which comes from behind the engine block bolted to the starter terminal, but think that this is incorrect. I think it should just be one or the other.

Anyone help?

[kenney]

That is correct the thick black wire runs from (3)to the battery + and the red wire from(3)to the alternator it is impossible to connect these wrongly

[kaisersolsay]

Kenney are you sure about that? I'm told on another forum that there should only be 1 connection to terminal 3, and that's the wire I have circled in red as this is the positive live wire. The other thick black wire I'm told is an earth.

[kenney]

Yes i'am sure this has been a standard connection since day1. Black positive 35 gauged, to terminal 30 on the starter,Black 16 gauged from terminal 30 on starter to the alternator,and the red on black 2,5 gauged to the 50 terminal on the solenoid, from the ignition switch.The black 25 gauge earth (1 on diagram) wire is attached to the engine support as in the digram you posted.The black wire which you found loose at the rear of the engine are you sure that that is an earth wire,as it is only the main earth wires from the battery to the chassis,and chassis to engine are black,most earth wiring are brown and brown with secondary colouring

[kenney]

The wire from the alternator to terminal 30 on the starter varys in colour on some engines it is red and some engines it is black so if you tell meg the engine code i can tell you what colour it should be

[kaisersolsay]

Engine code is AVJ. See picture below of actual wires in question.

http://i182.photobucket.com/albums/x309/kaiser_solsay/SAM_0574.jpg

[Crasher]

There should be a thick (16-mm) black cable from the battery + to the bolt on terminal which is line 30 and another coming off the bolt to the alternator B+ connection, also a 16-mm cable. To the other terminal (line 50) there should be a red/black 2.5-mm cable. The other terminal, 15a, should have nothing connected to it.

[kenney]

On the avj engine it is as Crasher has stated,anyway the wire in question runs to the starter,looking at the pic and i get the impression the terminal on the wire which is already connected to the starter,does not look too clean,short of that if you run a jump cable from the battery neg to the engine,that will eliminate a poor earth,if that does not help,then there must be something wrong with the starter

[Crasher]

Pull the plugs and turn it over by hand with a 19-mm 12 point on the front pulley, see how free it is.

[kaisersolsay]

See below link for a video of the slow turn over,

I've turned the motor via the crank bolt and it compresses nicely at TDC with plugs in.

I've wiped the starter off this morning for checking. I ran out of time to test the starter though.

Does it sound like the starter is goosed?

http://s182.photobucket.com/albums/x309/kaiser_solsay/?action=view&current=VID00012-20110205-1132.mp4

[kenney]

Sounds to me there is poor compression,have you the plugs out?

[pete99]

Sounds to me there is poor compression,have you the plugs out?
Sounds like that to me too.:approve:
Although- I would have expected it to spin faster.

[kaisersolsay]

Not yet but will try later on when out in the garage to eliminate. I'll nip to my mates also and get my compression tester back.

[kaisersolsay]

I replaced the bent valves and ground them in carefully. The piston rings were left in place. There felt like pretty good compression when turning the engine over with a spanner on the crank when doing the timing marks, in fact it was bloody tight to turn at TDC.

[kenney]

you need to do a comp test

[kaisersolsay]

Ok tried the following;

*Tested starter off car and all ok.
*Negative battery terminal to earth point using jump lead.
*Slackened gearbox bolts and turned over but no difference.
*Removed plugs and turned over and there appears to be no difference in cranking noise.
*Turn over by hand reasonably easy until you get to TDC then its quite tight to get past to next stoke.

*Removed rocker cam cover and counted rollers between the arrows and found 15 instead of 16.

How does the cam chain tensioner work exactly? Is it oil pressured? I didnt replace when rebuilding the engine and I'm now dreading that this was the issue that caused the bent valves to begin with (oil light came on and engine stalled...all exhaust valves were bent) and I'm now thinking that all I've done is fit new valves and they are now belt also???


Seriously debating whether or not I should drop it off at the local garage for them to sort!

[kenney]

Have you rectified the chain?

[Crasher]

Did you remove the sump and clean replace the oil strainer?

[a8 tech]

pm answered, follow instructions good luck

[kaisersolsay]

Yip sump was removed whilst the block was on the stand and the oil pump and pick up strainer were replaced. The old strainer was pretty clogged up. I also replaced the big end shells......is it possible they are tight on the crank as new and need to bed in? I haven't yet adjusted the chain tensioner.....what's the best way to get 16 rollers instead of 15?

[kenney]

(is it possible they are tight on the crank as new and need to bed in) NO unless you have put the caps on the wrong way around ,pm your e-mail address and i will send you the how to,you might be able to do it by just removing the tensioner,otherwise you will have to remove the camshafts

[kaisersolsay]

Kenney PM sent, cheers.

Ok, thinking once I have the cams timing correct I may tow to start it as suggested on another forum she may just need a pull to loosen things up.

[dean warren]

oops i cant delete this

[kaisersolsay]

Cam and crank timing marks are spot on.

[kenney]

Have you checked the compression??

[dean warren]

(is it possible they are tight on the crank as new and need to bed in) NO unless you have put the caps on the wrong way around ,pm your e-mail address and i will send you the how to,you might be able to do it by just removing the tensioner,otherwise you will have to remove the camshafts
i did this many years ago on a mk1 golf! but it was really hard to hand crank the engine.

[kaisersolsay]

Can't check my compression till I buy another tool. My pal has my tester and hes currently offshore in Libya! Will need to buy another tester tomw

[A4 Lad]

Just reading through your whole thread. What a bugger !!! Cars.... They do your head in !!! Good luck getting it sorted matey


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[kaisersolsay]

Carried out a compression check this evening and got zero reading from all 4 cylinders....gutted! Not sure what's gone wrong as the valves were ground into their seats and the engine timed. The only thing I can think and as someone on another forum has suggested, the woodruff key in the cam sprocket has broken which was the original cause for the breakdown. I hadn't removed the cam sprocket so didn't check.

I'll need to remove the head and inspect. How do you remove the cam belt without knackering your belt damper? The last time I removed the belt I couldn't get the belt damper piston to compress and ended up bending the tensioner.

[kenney]

A bit of bad luck then,as regarding grinding the valves,that is a thing of the past,to remove the tensioner,just keep an even pressure and it will eventually go down,let me know if you need any diagrams ;)never seen the woodruff key damaged on these engines,i fancy the one tooth out on the chain has done the damage,always turn the engine over a few times by hand before trying to start,after a major repair

[kaisersolsay]

Thanks Kenney, and thanks again for the emailed diagram you sent.

Apply steady pressure to the damper...could you explain where I should apply the pressure? I applied pressure using an 8mm allen key in the tensioner pulley but it bent the plate on the tensioner pulley.

[kenney]

Yes If you put too much pressure on it,you can bend the plate,an even steady pressure is how you do it.OR you can remove the tensioner,and put it in a vise just don,t close the vise quickly,then insert the locking tool

[A4 Lad]

Remove the damper and squeeze it closed, very slowly, in the vice and then lock it with your pin/drill bit. I cant be 100% sure but my TFSI was a tooth out on the cam chain when I bought it and had been since the last rebuild, almost 5000 previous. Its strange that you have no compression in ANY cylinder. Before ram stamming into removing the head again, what about tappets ? They could well be keeping the valves open. Did you drain them ? Im not telling you how to suck eggs but just trying to help

Edit - Sorry Kenny, we posted at the same time lol


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[kaisersolsay]

No probs Banger Lad, happy for the advise. I didn't drain the tappets.....how do I do that? I have poured a cup of oil on the cams with the cam cover removed and cranked it over. I have noticed that the cam timing is sitting on 15 rollers and not 16 so I need to sort this, however I wouldn't have thought it would show zero compression?? Can I check if the valves are opening or for bent valves without taking the head off?

[kenney]

If you remove the innlet manifold i think you can just about see the valves,if you can apply compressed air to each of the cylinders this will tell you if the valves are leaking,or remove the rocker cover and turn the engine and you can see if the valves are opening,you can also check for clearance between the lifter and the cam lob

[kaisersolsay]

I've timed the motor back up before removing the head and noted the position on the marks on the cams. Both inlet and exhaust cam marks are completely out despite the cam sprocket mark and cranks marks being bang on. Looking at both marks on the rear of the cams they are both out of time equally which strikes to me that the front cam sprocket has somehow loosened and thus bending the valves.

See pics below of cam timing marks...both are 2 chain links out to the left. I bit hard to see in the pics but you can just make out the cam marks.

If it turns out to be the woodruff key on the crank that has failed, if this a simple replacement job or is the cranks knacked?

http://i182.photobucket.com/albums/x309/kaiser_solsay/IMG00116-20110212-1051.jpg
http://i182.photobucket.com/albums/x309/kaiser_solsay/IMG00115-20110212-1051.jpg

[Crasher]

You need to pull the front pulleys of to check the condition of the cam and crank noses. The crank nose can be restored if damaged but only in situ if you have the special tool, hopefully it is not battered.

[kaisersolsay]

Crank pulley bolt will be pretty tight....any tips on how to slacken off?

[Crasher]

You need the special VAG tool 3415 or a powerful air gun if you can get one in there.

[kaisersolsay]

Just thinking.....no 1 piston sits at TDC when the crank pulley is lined up to the mark, surely this mean that the crank woodruff key is spot on? Would it not be more the case that the cam sprocket is duff? I'm going to try and crack the pulley bolt off tonight and examine.

[kenney]

According to what you say then there is nothing wrong with the crankshaft pulley,unlike some diesel engines,and i have yet so see a fault with the pulley on the same engine as yours,and they don't have a woodruff key

[A4 Lad]

Ok, just a thought but would it not be best to remove your belt, realign all your marks and turn her over by hand a few times, recheck your marks, put the belt and bottom pulley back on and see what happens ? Lets face it, what have you got to lose ?


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[kaisersolsay]

Turned her over on the crank a few times to double check and the cam marks were still out by 2 links.

[A4 Lad]

Turned her over on the crank a few times to double check and the cam marks were still out by 2 links.

No, I mean remove your timing belt and chain, realign her up properly everywhere, rebuild the chain snd belt and try her


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[kaisersolsay]

Removed the head yesterday mate.....all 8 exhaust valves are belt :mad:

[chivs]

Have you checked the starter brushes or cable to the brush plate?

[a8 tech]

Turned her over on the crank a few times to double check and the cam marks were still out by 2 links.

without seeing the engine in person I would suggest when fitting the camshafts with the tensioner you are installing the chain incorrectly and when removing the tension the chain is pulling the cams inwards


The distance between notches -A and B- on the camshafts must be 16 drive chain rollers. The illustration shows the exact positions of the 1st and 16th rollers on the sprockets. Notch -A- is offset slightly inwards in relation to chain roller -1-.

10285

10286

10287

– Insert hydraulic chain tensioner inside drive chain (2nd mechanic required).
– Place camshafts with drive chain and hydraulic chain tensioner in cylinder head.
– Oil running surfaces of both camshafts.
l Dowel sleeves for bearing caps and hydraulic chain tensioner must be located in cylinder head.
NoteWhen installing bearing caps ensure that the identification mark is readable from the inlet side of cylinder head.
– Secure hydraulic chain tensioner (pay attention to dowel sleeves).

– Tighten bearing caps -2 and 4- on inlet and exhaust camshafts alternately and in diagonal sequence (pay attention to dowel sleeves).
– Install both bearing caps next to chain sprockets on inlet and exhaust camshaft.
– Remove chain tensioner retainer -3366-.

– Check that camshafts are positioned correctly:
l The two marks on the camshafts must be opposite the two arrows on the bearing caps -arrows-.
NoteIf necessary, turn camshaft slightly backwards or forwards so that the two marks coincide.

Make sure after installing the chains are correct. the camshaft and the crank

10288

[A4 Lad]

Removed the head yesterday mate.....all 8 exhaust valves are belt :mad:

Oh no !!


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[kaisersolsay]

Going to take the easy route and buy a second hand head.
The engine is a AVJ but AVJ heads appear to be quite rare
to get hold off. Can I use another engine code head?

[kenney]

AVJ AMB BFB BEX use the same head

[Crasher]

The complete AVJ head (VW part number 06A 103 265 GX inc. cams and valves) is also the same on an AUM, AUQ, ARX, ARY, AWT, AWM, BJX, BBU and some others and that is all sorts of cars such as A3, Golf 4, Passat and even Polo GTI.