ThePointman

So I have been running my new to me p-car for a few days now with the radio off as someone had suggested so I can become atune to how it sounds under various conditions. While I was letting it warm up yesterday I noticed that after the oil pressure comes up the engine starts to knock a bit on what seems to be the drivers side of the engine. After it is warm the knock seems to go away. The sound is random and could be pinging maybe but I am not sure. Aparently the engine has 15-50 Moutil oil in it. I checked the levels after warm up and the oil level is just below the bottom mark on the dip stick (perhaps a bit low as it is not in between the two marks). Am I using the wrong oil or is something wrong with the engine? Seems like an oversight on my part as I never saw or drove the car cold. Even when the PPI was done. Thoughts?

Peter Zimmermann

Point: Knocking noises are never a good thing. Two points; (1) Do not garage "warm-up" the car - start and go, but keep the revs below 4K, and (2) If the oil level is not showing between the marks, with a warm engine, you should add oil until the level appears near the "min" line. Then, when the system is hot and the front cooler is open you can top it off to the correct level, about halfway between min and max. Your alternative is to drain the oil (engine & reservoir), add 9 quarts and bring the car to full temp. You mention "ping," when exactly are you hearing the noise that worries you? You can't hear a ping, define it as left or right side, while the car is in the garage. Ping usually happens during high rpm acceleration. If you hear the noise while driving try to determine the rev range when it's the most noticeable. If you hear it in the garage slowly bring the revs up and do the same. How many miles are on the car? Is the car's service history complete?
Pete

bourgeois911

I have something similar with mine (79 SC) and it drives me nuts. I have tried to locate the source of this sound and it seems to be coming from the oil tank if that's possible. I have used a pipe held against various parts of the motor (chaincase, cylinder heads, etc) and hear nothing unusual. If I place my ear to the right side rear fender it is very obvious and if I place the pipe against the tank or oil filter it is very evident. Like you've mentioned it seems to go away after warmup. It sounds like somebody dropped marbles in the oil tank or something.

ThePointman

That marble sound is exactly what mine sounds like. The engine has 240,000kms on it. The oil was changed on 7/7/2005. I do have all the service history and nothing has been mentioned about this noise. Maybe it is nothing and I am just worrying too much I have only had the car since Tuesday.

ThePointman

I think I know what is causing the noise now. If I put my hand on the plastic housing that surrounds the alternator I can feel the bumping casuing the noise. I think it is the alternator bearing that is making the chatter. I can wiggle the blades back and forth and make a simmilar sounding noise as when the engine is running. I think I will take the belt off start it up and see if the noise goes away.

bourgeois911

Interesting. I don't think my sound is caused by the same thing, but who knows. It doesn't seem to be RPM related, ie it doesn't seem to change when the motor is sped up. It almost sounds like an electric motor with crappy bearings but I don't know of any in that area of the motor compartment.

ThePointman

Meaning that when the Rpms increase your noise stays steady or goes away? With mine, as the Rpms increase the noise goes away.