johnu

So I finished the intake refresh including new tensioner pads and proper cam oil pins. Started the car, ran with no issues. Went for a drive to heat the oil then did an oil change. On the next start, the oil pressure was at zero for a couple seconds and there was a cam chain rattling noise. The noise stopped as soon as oil pressure shot up above "5".
I have never seen this before after an oil change. Should I be worried? Should I crank the engine with the fuel pump fuse pulled next oil change to get the oil pressure up before starting?
Thanks
John

FredR

John,

It sounds as though you lost oil pressure to the cam followers so the obvious question is why? This is typically caused by the ball check not holding so next time you start the oil pressure in the tensioner circuit has to build to stop the chain rattling. I take it you had no intervention in this circuit?

I suppose the other question working on the premise of "the last job you did", would be whether you installed the pins in the end oil galley correctly. Not sure if that would explain your symptoms but...?

johnu

Everything was fine on the first three starts after the intake refresh. It was only after the oil change that I had the momentary rattle. I guess I will have to monitor the next few starts and see if it happens again.

Mrmerlin

silly question but, why are you changing the oil is it old?
what was the new oil that you used?
did you prefill the new filter?

johnu

Oil was almost a year old. Used 20w50. Did not prefill the filter.

Mrmerlin

OK ^^^^when you change the oil in a 928 its a great idea to pour about 3/4 of a quart into the new oil filter before screwing it on.

NOTE this will reduce the amount of time the engine bearings will run without oil pressure.

johnu

Always learning something!
Thanks
John

kmascotto

John, that sounds like a brief lack of oil in the lifters....not cam chain rattle.