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I am feeling increasingly guilty about not changing the hydraulic tappets on my 20V Audi Coupe. One of the guys at work commented on it the other day. So far I have been put off by the horrendous mechanical complexity (2 camshafts, 20 valves, belt drive to one cam and then a chain drive to the other one). Has anyone done a tappet change on the 20V engine, and is it a DIY job? The Haynes manual is a little vague. The car could also use a new set of shock absorbers, so I'll probably take it off the road for a while, and buy a cheap car (NOT Martin Glover's Peugeot 309) to keep me mobile while I sort out the Audi at a leisurely pace.
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I have removed and refitted a cylinder head on mk.2 golf 16v's. Its not that hard a job. I think the Audi engine is the same apart form an extra cylinder.
VAG wanted silly money for the tappets when i rang, something like 15+VAT each! I bought mine (Febi) from Vince at Stealth Racing for 5.50 plus VAT, i think yours may use the same followers. If you work carefully , and turn the engine over by hand to check your work before starting, you should be fine. However if you get it wrong on this engine, the valve will headbutt the piston so hard it will punch a hole right through it. A friend of mine got it wrong. He also found the head of the valve jammed in the inlet port of his ported cylinder head. Its not difficult, but the cost of getting it wrong is great. Additionaly you should change the cam chain. some people change all the followers hoping it will cure the noise, when its main cause is a worn chain. The mk.2 engines tend to clatter on the inlet side when the chains are worn.
If you are going to all this trouble you might want to throw in some fast road cams. If the tappets are noisy, you could possibly have a worn cam lobe as well, although the VAG cams are very tough. kent cams are as cheap as 120 exchange from Rally design ( www.raldes.co.uk ) (thats 4cyl price). Unfortunately, i doubt they will have ground them straight, forcing you to buy a vernier pulley, so take this into account when estimating a price. Kent do cambelts as well, which you might as well change when you have everything apart.
if you want any info on getting hold of the bits and pieces let me know.
Ben
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Richard,
I did the hydraulic tappets on our A100 2.2CD (10 valve) but this is not really comparable. I never changed the tappets on my 90-20V, so I can't help there.
I have had the head off our 80-16V and this is (kind of) similar to your engine, only minus a cylinder. Like your engine, the 16V has a single cam belt pully and a chain at the rear of the engine to drive the other cam.
Ben Chapman (earlier reply) said some very useful stuff.
I think that the Haynes manual isn't bad, and at least you get the torque settings (MOST important as the bearing cap studs are weak)! Also, it's worth (IMHO) getting a new Audi original rubber cam cover gasket (the OEM cork ones are terrible and the old one will be compressed and might not seal properly).
Good luck!
Martin.
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Thats right about the cam cover gasket. Becareful what you buy, some of the cheapo ones on the market arent worth having. Usually they leak at the distributor end and cause all kinds of problems there, but they can leak at the other end and cover the cam belt in oil (this is on a 4cylinder- i think its similar). I got mine from Euro Car Parts and it has been fine. If you are tight you might wont to try resealing you existing one with Silicon, but i dont think its worth it.
One thing to remember is that the cam belt should be set tighter than for the two vale per cylinder models. Some people say a quarter of a turn compared with a half turn- but i didnt find this much use because it all depends how hard you twist the belt! Best to do it up a little on the tight side, and then go to a decent VAG garage to get the tension set with a proper gauged tool.
Additionally i would recomend you use some Valvolene 5W-50 full synthetic oil. This will quieten the tappets down on its own. I think 0W-40 and 5W-40 grade oils are too thin for this engine at normal operating temp. Get it for about 13-16+VAT from Southern Motor Factors.
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Ben and Martin
Thanks very much for your amazingly useful advice. I will definitely have a go at this job when I have got hold of the parts. I'll try German & Swedish first - they are just up the road from where I work. I might see if I can find someone to rebuild the distributor at the same time - it has a lot of endfloat on the shaft (common problem with these) and rattles. New distributor is £400 from Bosch (I didn't dare ask Audi what they wanted for one).
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Richard
On the subject of 20v distributors, I think you will find they are a whole lot less than £400 from VAG parts, at least they were a few months ago. The new unit comes with a metal driven gear instead of the original plastic item which often breaks up. Unfortuneately they won't or can't supply the gear on its own and I
don't know of any source of these so how would you get your old unit rebuilt?
Would be interested to hear if you know of any rebuilders of these.
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I have heard that Stealth Racing rebuild distribuors for people. Might be worth giving them a call. An oil seal failed in my friends VAG distributor. We couldnt find anyone that had the parts other than Stealth. They sold us a seal for £4. Cheaper than a new distributor a £100.
Ben
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Richard,
Glad to be of help....
Just remembered - don't forget a new oil seal.
On the point of tensioning, I believe that you can trust the Haynes manual on this point. But as a 'general' guide, on the longest run between pulleys, you should be able to just turn the belt through 90 degrees with your fingers.
Martin.
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David
I was going to get an engineering shop to do the work - hopefully they can remove the drive gear without breaking it. I wonder if 10V cars have the same drive gear? Lots of them in breakers yards. Anyway, I'll ask South Hereford Audi for a quote on a new distributor - they do a good mail order service and gave me a reasonable discount on a knock sensor a few months ago.
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My Audi 100 5cyl 2.0E - rattly tappets at 80,000......'they all do it, squire - leave it alone'. It disappears when warm, still wonderfully smooth and using only around 800mls per 10,000 now at 147,000. Different viscosities seem to make no difference. Wise advice!
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