Cambelt Change Disaster....... gratefull for any help!!

Audi thru'n'thru

A2OC Donor
After 30 years a 'DIY mechanic' I felt it was almost a 'rights of passage' to undertake my 1st ever cambelt change on my 2005 BHC tdi, togethor with a new water pump and alternator belt.

The guys on here helped me find the correct kit; I read all the posts I could find, and compiled instructions from various sources and watched relevant stuff on youtube.

BUT I still managed to '**** it up' big time!! I ended up removing the crankshaft alternator pulley along with the crankshaft belt drive cog..... I'm still not sure how or why I didn't realise that would be a seriously STUPID thing to do - maybe it was the struggle I had to undo the crankshaft nut that addled my brain? I'm not even sure that I really needed to undo the crankshaft pulley nut in the first place? [photos 1 to 3]

1 Extension bars to undo crankshaft nut.jpg2 shows Extension bars on crankshaft nut.jpg4 crankshaft at TDC postion - maybe.jpg5 cambelt TDC teeth NOT at 4Z TDC position.jpg3 Should NEVER see - crankshaft WITHOUT the belt cog.jpg

I recognised the crankshaft and cambelt were NOT in their correct TDC positions for me to remove the belt - so I decided to follow the procedure to loosen the tensioner in order to get the crankshaft belt cog back on.

In the process of wrestling the belt back on, I managed to move the cambelt and the crankshaft postions - which I tried to re-position at best I could; the crankshaft cog is a 'keyed' fit onto the crank so I believe it is in the correct place?

Photos 4 shows the crankshaft pulley at what I THINK is the correct TDC position i.e. the mark lining up with the locking pin in position BUT photo 5 shows the cambelt sprocket is some way short of the 4Z (TDC position for the BHC engine). I think I have turned the crankshaft clockwise before I refitted the cog and belt [by perhaps 25 - 30 degrees].

So I'm stuck at a point where my knowledge and experience is exhausted and the risks of continuing [and making things really worse] is greater that the inconvenience of being without my daily driver until I can safely extricate myself from the enormous pile of poo that I've lept into!!

n.b. the engine does turn without any bangs or grating when I turn it by the crankshaft bolt.


MY BIG QUESTIONS:

1. Will the crankshaft still be at the correct TDC position? OR do I need to do additional checks / activities to be certain of this?

2. Is my logic correct that the cambelt sprocket will be have been effectively retarded?

3. IF I remove the belt and advance the cambelt sprocket to the TDC position '4Z'; Will I then have the cambelt sprocket in the correct position to lock it and proceed? How can I be certain it is correct?

4. have I completely lost the plot and need to phone International Rescue aka Thunderbirds!!


I do appreciate that this is a lot of info to assess but I will be eternally grateful for ANY help, obviously I'm very happy to provide more info and answer any questions.

I did look a for a suitable emoticon but could find one for 'desperate'.......

Many thanks, Peter

p.s. sorry the photos have got rotated by the upload and I can't seem to correct them.
 
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I'm not really suitably experienced on the TDI engines so I won't comment on the timing except to say the obvious, don't try to turn the engine by the ignition. What I will comment on is the crankshaft pulley.

These are, as you said, normally keyed to the crankshaft to ensure they sit in the correct position. This is normally carried out with a wood-ruff key. It is essential that the bottom crankshaft pulley is put back on in the correct position and the wood-ruff key is secure. If the key falls out while running(this has happened to me before) then the engine is kaput.

If your not sure where to go from here, I would enlist the help of a member that may be close-by for some assistance. It may be worth the wait rather than risking any further damage, as you've already said yourself.
 
Crankshaft pulley can only go on one way, thanks Topsie.

I'm not really suitably experienced on the TDI engines so I won't comment on the timing except to say the obvious, don't try to turn the engine by the ignition. What I will comment on is the crankshaft pulley.

These are, as you said, normally keyed to the crankshaft to ensure they sit in the correct position. This is normally carried out with a wood-ruff key. It is essential that the bottom crankshaft pulley is put back on in the correct position and the wood-ruff key is secure. If the key falls out while running(this has happened to me before) then the engine is kaput.

If your not sure where to go from here, I would enlist the help of a member that may be close-by for some assistance. It may be worth the wait rather than risking any further damage, as you've already said yourself.

Crankshaft pulley can only go on one way, thanks Topsie.
 
Jigsaw (Gary) lives in Norwich, although away in Melton at moment, but can pop round and help
 
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Hi Peter
Sorry to hear if your problems, in general terms you start with the crank shaft in the locked position and then line the cam wheel up and put the belt back when the tensioner is slack and then finally adjust the position with the three 13mm slotted bolts. ( not sure why you took the cam pulley off but the stack of bricks was what a great solution and proves you have the ingenuity to see this through and find the solution )

I didn't see any actual cam peg fitted (just a white mark on the cam wheel) when you have the cam peg fitted right through the wheel into the camshaft that is the thing that gives you the confidence to know that you have things right.

Not sure how far "out " you managed to get things when it all went wrong but with the crank locked the camshaft can only be in 2 positions, one correct and one 180 degrees out so if it never got that seriously out of control it should still be able to wind the camshaft back to the correct position. So then tension the tensioning pulley roughly correct and wind the engine over by hand two complete revolutions from the crankshaft carefully to ensure nothing interferes then lock the crank and try the cam peg. If the peg doesn't go in just undo the three 13mm bolts and rotate the slots with a 19mm cranked ring spanner till it goes in, tighten it up and retention the tensioner and repeat the procedure until the peg goes in first time and the tensioner pointer is between the two marks. This may take 5-6 goes but the precision is worth it.

The cam peg goes right at the back of the cam at the top at about 10 o'clock, if you had the pulley off you should have seen the slot and hole it goes into. Depending what make of peg you use it is a very tight fit and I have sanded the peg to chamfer the entry and greased it just to feel the ultimate fit.

Hope that helps and don't give up, just sleep on it and attack it when you are mentally recharged as a day of doing that really depletes your mental energy particularly if you haven't done it before.
 
Hi Peter
Sorry to hear if your problems, in general terms you start with the crank shaft in the locked position and then line the cam wheel up and put the belt back when the tensioner is slack and then finally adjust the position with the three 13mm slotted bolts. ( not sure why you took the cam pulley off but the stack of bricks was what a great solution and proves you have the ingenuity to see this through and find the solution )

I didn't see any actual cam peg fitted (just a white mark on the cam wheel) when you have the cam peg fitted right through the wheel into the camshaft that is the thing that gives you the confidence to know that you have things right.

Not sure how far "out " you managed to get things when it all went wrong but with the crank locked the camshaft can only be in 2 positions, one correct and one 180 degrees out so if it never got that seriously out of control it should still be able to wind the camshaft back to the correct position. So then tension the tensioning pulley roughly correct and wind the engine over by hand two complete revolutions from the crankshaft carefully to ensure nothing interferes then lock the crank and try the cam peg. If the peg doesn't go in just undo the three 13mm bolts and rotate the slots with a 19mm cranked ring spanner till it goes in, tighten it up and retention the tensioner and repeat the procedure until the peg goes in first time and the tensioner pointer is between the two marks. This may take 5-6 goes but the precision is worth it.

The cam peg goes right at the back of the cam at the top at about 10 o'clock, if you had the pulley off you should have seen the slot and hole it goes into. Depending what make of peg you use it is a very tight fit and I have sanded the peg to chamfer the entry and greased it just to feel the ultimate fit.

Hope that helps and don't give up, just sleep on it and attack it when you are mentally recharged as a day of doing that really depletes your mental energy particularly if you haven't done it before.

THANK YOU d4v1dsm4rt,
You've explained everything clearly and I think confirmed that my logic was correct; and you've given me the knowledge and confidence to proceed.

The cam pulley peg is 3-4cm long and I could only get it in half way which didn't feel right to me - so now I know it has to go in all the way and that I can loosen the pulley and 'jiggle it' a bit. Also, very sound advice on how to get the right fit and enable me to be 100% sure it's right.

I'll tackle it again in the evenings after work this week and I'll let you know how I got on.

Thanks again.
 
Amendment

Glad to be of some help, I have been in similar situations and all it takes is someone to give a few pointers after having a problem to spur you on to complete it and I think that is what clubs like this are for.

To correct what I said before about the peg it goes in at about 7-8 o clock
see here
A2 timing belt.JPG
 
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