audi coupe 16v timing chain

[beyerdynamic]

Hi there,anybody know when your suspose to change the timing chain on a ACE 16v ,i`ve heard from somewhere that you change them once to every two timing belts,mine sounds very rattly at moment,if i use the old listen with the handle of the screwdriver trick,i can make out alot of rattling from the timing chain end.

[scotty33]

I go along with what you said! I fitted one in my 20v at 147k and it made a lot of difference to the top end noise.
If it is noisy I'd say change it, you wouldn't want it to let go..

[beyerdynamic]

Have ordered a new chain from my local audi dealer,so will be dealing with it when it arrives,is it a relatively easy job?,i`m doing it myself with haynes manual for company;so long as i take my time it should go ok.

[scotty33]

If you are comfortable with removing the cams, it is not a hard job. You need to keep the cam caps in the correct positions and the same orientation they come off. With the cams off, the tappets are exposed, I would seriouly recommend you renew those as well, while you're in there. (£6.50 each - eurocarparts)
I found the hardest part was getting the inlet manifold bolts to undo. Some were damaged by previous mechanics, I had to hammer a torx head bit in as they had done! Even the undamaged ones were very tight, I bought a 6mm allen key bit for them, I doubt a normal allen key would work

[beyerdynamic]

Thanks,will look into it;like you said seems stupid not to do it for peace of mind

[beyerdynamic]

Have started the timing chain replacement; have removed inlet manifold,and cam cover,about to remove cams and chain,what should the sprockets look like?,they seem to have rounded teeth,not like i expected;there seems to be wear in the teeth,the engine has done high mileage and the cam lobes do appear to have wear on them;what i don`t want to do is put the new chain chain on worn out sprockets,anybody got any advice?.

[scotty33]

I've had 6 of these apart, they were all very rounded, not pointed like bike sprockets! If you can see the profile of the teeth is worn heavily one side then newer cams may be needed. From a performance point of view, now would be a good time to find some Volkswagen KR or ABF cams anyway. Other than that, have a look at it reassembled, see how much less slop there is in the new chain, hopefully you will be reassured.

[beyerdynamic]

Hi there,could you give me some pointers on replacing the cams,i`ve tried a couple of times so far,trying to keep timing marks together when torqing down bearing caps is a pain;is there a method or is it simply a case of trial and error,appriciate any tips you might have.thanks.

[scotty33]

I have changed heads over on 16v motor's not had the cams out so not run into this. I had no problems with the 20v, but it has a different relationship between the cam lobe centrelines, and the timing chain is at the front so it's easy to see what is going on.
I'm guessing the cam(s) is turning before you can get the caps tightened down? I'm guessing that the cams which are pointing 'down' and making life difficult are at the back near the chain?
I would try to torque down one cam first, if it turns as you do this, ensure that the other cam is allowed to turn by the same amount. When you torque the second cam down, they should still be timed to each other properly, just may not be at tdc? If it is too far out, you risk bending inlet valves. It might be a good idea to turn the crankshaft 90 degrees, while you get the cams right, at this point all pistons are halfway up/down their bores.
If you can't get it by that method, still do the 90 degrees with the crank, then time the cams together in your hands, but turn them until the lobes on cyl 3 and 4 are NOT down. It should be easier to torque both cams down together, without losing their timing. Then turn the cams around until the timing marks line up and THEN TURN THE CRANK BACK BY THE 90 DEGREES, VERY GENTLY WITHOUT USING FORCE, if it won't go, turn the crank 270 degrees, the other way instead.
To be honest, this is not good advice, but it is what I would try. If you are not clear what you need to do, please don't try this. I don't want you stuffing your motor because I did not type enough!

[beyerdynamic]

Success!, cams are in and spot on first try;put the chain on the sprockets on the workbench(sprockets facing down)made sure the dots were lined up then dropped them into the head,checked to made sure they were still in right position then tightened the caps down;they were off after that but once i brought the camsprocket round to the tdc mark they were bang on;put all the rest of the stuff back on,all i have to do now is run the engine to fill up the tappets,should be ok after that,will keep you posted as to final conclusion,thanks for your advice.