Boy Wonder

My 100S had a ticking lifter that was identified by removing the valve cover and manually trying to depress the lifters, with one being very spongy feeling, while the others were stiff. I replaced it with a new lifter but the ticking is the same. It ticks all the time (not just on warm-up). Does the lifter need to be "primed??" in oil?? The bentley manual doesn't mention anything special, other than replacing the oil check valves in the engine valley if the tappets "tick" on start-up. My only theory is plugged oil passage in the head. Thanks in advance for any help.

1992 100S 165K miles
10-30 conventional oil (switched from 20-50 GTX)

ShoppingKartRacer

why replace one? might as well replace all of them...

20VT90q

You are supposed to pre-soak them in oil for about an hour or so. I'd would think if that lifter was the bad one the oil should work it's way by the lifter if you give it some time. How do you getto the lifters? I thought it was harder tan just taking the valve cover off? How long did it take you to do te one?

simply audi

Try replacing the pressure relief valves in the heads. If they have not been replaced by now I'm sure they are due.They will certainly give you the symptoms you describe. Also at this stage they may come out in pieces. Good luck Simply Audi

Boy Wonder

Procedure:

Remove valve cover
Undo timing belt (at the cam pulley for the bank of cyls that you are working on)
remove cam, noting the position and orientation of the bearing caps. (no need to pull cam pulley unless you want to change front seal)
remove lifter(s) (tappet)(s)
If you are palnning to re-use any, note which hole that they came out of.
Drop in new lifters and reassemble torquing bearing caps in the proper sequence. (Bentley manual) Reinstall timing belt (Per Bentley manual)
WAIT AT LEAST 30 MINUTES before starting the engine, in case the lifters are "overly pumped" which would allow the valves to contact the pistons; which would turn a moderate repair job into a major headache.

Speaking of valves slamming into pistons.....

At about 140K miles my idler bearing for the timing belt failed (belt was replaced regularly)causing the valves to slam into the pistons, now I have a wonderful set of mangled valves for paperweights! So, always replace the idler bearing for the timing belt, unless pulling the heads and doing valve jobs is your idea of a good time.