Hi all,

I have not posted for a while as I am in the middle of my transition to Chile. You might recall I had my 928 for sale a couple of months ago. Well, turned out my brother in law decided to buy the car and let me use it until I move. Great thing since I already sold my BMW daily driver and am enjoying to drive the shark on a daily basis when I am in town. And she stays in the family.
Car has 150,000 miles, 1989 5 speed.

I am trying to diagnose a couple of things before I give him the car. I will make two separate posts not to cloud the system.

There is a ticking noise that seems like something is rattling or clicking with the engine rpm. It is not present all the time, but I'd say about 75-80% of the time and it is more noticeable between 2-3K rpm. It has been there since I bought the car, although it seems is getting a bit louder. It seems to be around the MAF on engine rear / passenger side. When I touch the fuel damper and fuel rail, that seems to be vibrating at the same frequency of the noise. I don't think it is lifters. Oil pressure is good, during recent Intake Refresh the rear cam plugs were in place and the noise happens also at idle and does not go away with higher rpm/higher oil pressure. Using Mobil 1 20W-50 I believe. I suspect injectors or fuel dampeners, but maybe air pump?

By the way, towards the end of the video you can see the metal tube (?) that runs by the side of the air filter housing shaking. It is not touching anything, so it is not the culprit.

Please review the video and help me out.


Thanks in advance

 

Sounds like a possible bad fuel injector, as it is squeaking.

If it was more of a knocking noise it would be a lifter. Get a new set of fuel injectors as you 928 is at the age where they begin to give up.

I'm sure Roger or Mark can help you get the correct set of bigger 24lb injectors the S4 should have had.

 

Sounds like something rotating, like the air pump bearing. Maybe pilot bearing?