I am new here and new to the 996, but old time mechanic, mechanic at a indy porsche shop for 3 years in late 70s so these typ of cars are not really foreign to me. Well just picked up a 99 C4 with 135K miles from a dealership, no records just car fax showing it led a sheltered life on the west coast. Really clean car runs great. So following due diligence i pulled the oil filter and replaced with a LN spin on and cut the old filter open, then pulled the sump and checked to see what was inside. Looked like the pan had never been off. Picture below shows the plastic rubble 2 small aluminum chips and what looks like the corner of a piece of ferrous sheet metal. if you look closely there are stamp marks at the edges. My son (that is general manager of a machine shop) says the aluminum pieces look like chips from a drill. The oil filter had no metalic particles and some smaller pieces of the black rubble plastic, like 4 or 5 the size if a pin head.


I felt ok about this as there were no small shavings indicating an IMSB failure. Also used a stethoscope on the IMSB area of the cases with no apparent strange noises. Buttoned it up with 5900 and filled it up with JG DT-40. Took 10 quarts, is that normal after having the sump off?

Just wondering what others think?

Should i be replacing my 4 and 5 chains and the sliders? (saw this on Flat6 web site)

Thanks for any input, looking forward to my first track day.

 

SWARF like that could have been in there from the beginning. Others have found similar junk in the pan.
Although I've never seen anyone find a penny before.

 

Copper content is signs of the engine on it's last leg...

 

Wow! A 99 that had a 2006 penny in it. I'm going to go out on a limb and say that was not installed at the factory!

Seriously though, no idea what that plastic rubble would be, but it's clearly not part of that dreaded bearing!

 

The black plastic could also be pieces from seals, swirl pots, pickup, baffle, AOS/OVS, oil fill tube, cap parts, vent/baffle, possible gasket material. Don't recall what else is black plastic.

 

The bits 'o plastic could very well be fragments of a previous (or current???)wWater pump impeller

 

This would seem almost impossible and would also have to include a compromised AOS/OVS, oil cooler, or engine case. All of which would be obvious.

 

The turbos have a dime in them

 

Doesn't look all that bad to me. Given the large sizes it doesn't have appeared to gone through a scavenge pump or the high pressure oil pumps so this suggests the stuff got into the sump during the engine's assembly.

If the oil filter housing oil and filter element were free of any scary bits (finer particles of alum., ferrous, pieces of o-rings, or plastic material) what you found doesn't look all that bad to me.

You can replace the chain tensioners, guides, if you want. Trouble is ok you replace these but there are a number of other things that can go wrong with the engine, so you have to consider fixing those things, too. Then there are some more. I think the count is up 25 or 30 failure modes and to address some of these requires extensive work.

 

Probably TC guide material.

Yes, I believe the early "5 chain" engines need to have several of their chain guides replaced as preventative maintenance at some point. Looks like your car's time has come.

Don't know what to think of the other debris in there.

 

I think he could be right. Most of the guides are brown but seems like one may be more black or darker plastic. Better drop the engine, bruh!

 

Just got the car and it is now cleared for use. Next oil change i will drop the pan again (super easy with the two post hoist i just installed in my garage) and take another look. If i see more plastic debris i will consider dropping the motor for a more thorough investigation and part replacement. I think i can replace all the guides but the #1 guide on the IMS drive chain without full dissassembly.

Thanks for all the input.

 

The black plastic stuff is most likely from the Vario-Cam chain wear pads which should be replaced by 70,K miles. Unless you are confident they have already been replaced with the updated "brown" version you should replace them A.S.A.P. as that is a lot of material & somewhat excepted given your mileage. The cam chains WILL derail once the pad breaks thru. You should check the cam timing variations also. Pics show typical pad wear @ 90,K miles.

 

I was wondering about this. I am going to have the local Indy hook it up and let me know the cam timing traces and the over rev history. Then i was planning on replacing the 4-5 chains and the sliders in the near future. The valve covers also do not look like they have ever been off. From what i have seen it looks like i can just lower the rear of the motor and do this in the car.

 

Does it really matter where the debris came from. You will probably get more on the way to ****ing the car up by tracking such a well used engine anyway. So it lead a sheltered life on the west coast with 135000 miles on it DUH.