The new Porsche's probably do run 0w20 Mobil 1, which is where he probably got that from... but your car's about 20 years from new...

 

My car is as far from new as could be, I've only got 5 years on it. I'm an antique!

 

Ok so I changed the oil to 20w-50 turned it on and still get noise. At anything above 1400rpm it goes away or is at least to me, not noticeable. Oil pump or rod bearings? What's easier to replace... How do you replace a rod bearing, I usually stick to the top end.

 

i really doubt these oil pumps go bad. could be a bad oil pressure relief valve? I'm not an expert.

but obviously a knock is not good and you probably have to find out first where the knock is coming from. i'm guessing rod bearings.

and yes you should run thicker oil in a 944 engine. the problem may have been caused by someone running the thin oil in it.

 

I replaced everything that was connected to the oil cooler next to the oil filter a few months ago.


HOWEVER... Looking through my records, because I'm dumb... I forgot I had the timing and balance belts done shortly before the noise happened. When it was fixed they noted that the balance belt was completely destroyed (engine ran rough prior) It ran well for about a month before the knocking, but I was getting a little belt whine, sounded like I had a big super charger on a little engine. Since the knock there is still a whine, I'm 95% sure it's something to do with the balance shaft and/or belt and was never alarmed by it.

Thoughts? (Yes this car is a barrel of fun.)

 

http://www.clarks-garage.com/shop-manual/lube-06.htm

That'll at least get you TO the bearings, when you pull off the pan, they're right there. Oil pump is on the front of the engine, under the crank pulley. When you changed from the 0W20, and put in the bigger stuff, did you have an einstein afro of metal shavings on the magnetic drain plug? any metal chunks?

Can you tell if it's coming from the top of the engine? Finally, when you had the cam tower off, did you check your lifters to find dead ones? I've confused the sound of a lifter with the sound of a rod bearing before... and a ton of money later in parts, realized the bearing didn't spin, and yeah... not happy.

 

When I drained the oil there was no metal chunks or "Einstein afros" it was for all intents and purposes normal clean oil.

I would have previously bet a large sum of money that it was coming from the top end of the engine. With the new cam and lifters I'm just not sure. Maybe its coming from the middle? I can hear the noise from the tailpipe, it's subtle, but it resonates through the whole system.

 

Make sure that the crank pully bolt is tight. If the pully was taken off while the belts were being done and wasn't torqued to spec you could have a oil pump issue. I think it is 150 ft lbs.

 

Thanks Robert! I'll take a look see. I was also recommended Marvel Mystery Oil to try and help out a little... Thoughts?