At one time, my S was ticking as if she had a sticky lifter.
Found that one of the exhaust gasket was leaking. Tighten the exhaust manifolds and see if that fixes
the problem. Good luck!
Ah! The sticky lifter syndrome. I've heard it on a few 928s that I have checked out. Does it sound like an old Singer sewing machine? That's it. Since the lifters are hydrolic, the only solution (other than a complete lifter replacement) is to use clean and light weight oil for awhile. As this oil will be flushed out and replaced often, I would not opt for synthetic. I would use a good quality oil with detergents (all the major brands have them). Once the noise subsides (it may never fully go away) then use a good synthetic. Mobil 1 is fine.
Occasional lifter noise is part of 928 ownership. It usually goes away on its own. If not, I've had good luck with any of several commercial "top oils", like Risolone. You add it to your oil and run the engine for a few minutes and whatever is causing the lifters to stick will disappear. This problem is especially common on cars that have been stored for a while, like over the winter, and I've seen it fairly often on both 928s and 944s, and on both two and four valve engines. I have never had one fail to respond to the above treatment.
One of the most obviuous culprit for lifter (tappet as the manual says) noise is a sticky (and leaky) Oil pressure control valve. The good news in the 928 is that we don't need to adjust the valves, because we have an hydraulic automatic tappet adjustement. This relief valve is located under the cam shafts cover. It is a tiny little metallic ball pushed on a seat by minuscule springs...Not the kind of stuff you want to drop in the depth of your engine bay! The manual has a detailed procedure, and since this is quite delicate I would suggest to take a look at it.
I have a lifter that gets noisy. I tried Risolone with no improvement. A local mechanic recommended Lucas Oil Treatment and it quiets it down. Changed oil last week and it got noisy again. Added Lucas yesterday and it is quiet again today. Guess I'll have to add it with each oil change. BTW I am not connected to Lucas in any way.
78 928 US 5 sp
78 928 Euro AT
80 924 NA 5 sp
Common 928 problem - used to happen to my 87 all the time. Add about 1 quart of automatic trans fluid to your engine oil and take the car out for an extended cruise (25 minutes or so). Drive the car fairly hard and take it to redline a few times. Change your oil within 500 or so miles and your problem will be gone!
Brian E. Buxton
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