Metal in oil filter

I recently purchased a 2000 996. The previous owner told me that he had the intermediate shaft repaired about 1-2 years ago, as well as the clutch replaced in the last 2 years. I confirmed these details with the shop that did the work (Omega Motorsports in Jacksonville FL). I believe the last oil change (prior to today) was 5k miles ago, so I gave it an oil change today. When I removed the filter, I inspected in the folds and found significant metal flakes. The flakes look like pieces of bearing material (not confirmed in any scientific manner). Some of the flakes were 2mm-3mm (estimated) but very thin, like a foil. I collected an oil sample that I plan on sending for analysis (collected as a precaution while draining the pan fortunately). My question (after my verbose background) is: what is the most probable cause for the metal? Is it probable that this is residual metal from the intermediate shaft failure that was not sufficiently flushed out? I really appreciate any advice that can be offered, as I do not wish to tear down the motor to find this is just residual from a prior repair that could have used additional flushes. Also, given that the material resembles that of bearing material, I wanted to know, are the main and rod bearings (generally) replaced during the intermediate shaft replacement? I can contact the shop to confirm, but given that they did not tell me of the leaking spark plug (oil protection) tubes, which I saw after leaving there (when inspecting the car), I am hesitant to trust them. BTW I asked them about the leaking tubes after purchasing the car and they then informed me that they were aware prior to my purchasing the car. I had asked for their input on the vehicle prior to the purchase, and they told me it was a good car, no mention of any issues. Thank you very much for the input, and I apologize if similar topics have been covered in other posts. However, given the specifics of this (prior intermediate shaft replacement, etc) and potential engine issues, I thought it prudent to get a detailed answer for my concern at hand.

I don't have an answer to your particular problem but for those who do, I will add one: Are you guys using the magnet oil plug from LN engineering to trap potential metal flakes ?

I made my own magnetic drain plug and it works quite well. Consider using one of those periodically to see if you are still pulling metal out of the engine. (I made mine with high strength magnet, a regular aluminum oil plug, and some JB Weld. (I subjected it to ESS testing with freezing to oven heat--hasn't broken down in several thousand miles).

Quotes source post: 7650379

No apologies necessary. You're concerned as anyone would be faced with the same situation. Has there been any oil change since the shaft replaced? The first oil change after a shaft replaced -- and engine rebuild -- will almost certainly contain some material even if the engine healthy. Depends upon what the metal is and how much there is. If non-ferrous, alumimum, and not very much, might just be normal. Large thin flakes suggest aluminum. The oil pump will flatten any alum. pieces out like foil. All engines shed metal though as they age and run they shed less. Still a larger piece of metal might have been ingested by the oil pump and ended up in the filter. The engine repair might have disturbed something. If the metal is ferrous (less likely based on your description of the pieces) its presence could be serious. Depends once again on how much there is. Main and rod bearings not an automatic replacement. Since car a 2000 MY I'm going to assume car repaired outside of a Porsche warranty. Do you have any paperwork that covers the engine rebuild? If the bearings were replaced this would be noted in the parts section of the bill at least. Parts distributors do not give bearings away to engine rebuilders and what the shop had to buy you bet it charged the owner for these items. How does the engine sound? Quiet? If so odds are the IMS ok. An engine with a sick IMS sick enough to shed bearing material is not going to be a quiet engine is my WAG. You can't do much now. If engine quiet, change the oil, filter, clean the housing up super clean and run the engine a bit. Idle and let it warm up, or even take it for a drive. Nothing hot and heavy, just easy does it. Oil flows just fine at 2500 rpms as it does at 6500 rpms. If during this drive the engine starts making any noise at all shut it off as soon as it is safe to do so and do not start it again until noise diagnosed and fixed. But if engine remains quiet and symptom free, bring the car in and drop the oil filter housing and pour oil into clean pan along with oil filter housing and see what you see. If engine not quiet then the metal in the oil along with the abnormally noisy engine and it has to be an unhealthy noise too is very likely a sign of possible serious trouble. The engine may be salvagable but it won't get better with more running. It will almost certainly get worse. Sincerely, Macster.

Macster, thanks for the reply! I cannot say one way or the other in regards to oil changes since the IMS repair (I have had the car for a month and a few hundred miles). I will contact the shop that did the repair and see what records I can get. The engine sounds fine, and I drove it last night before and after the oil change and it sounded fine. I have been planning on autocrossing it today and I guess I will continue with those plans, as I autcrossed it last weekend also (could have loosened some material). My thought being that I have no running complaints. My hope being that the material is residual metal from the IMS repair. The repairs were done out of warranty and currently I have no documentation for them. Thanks for the input. -Tripp

You will learn a lot from the used oil analysis. Smart move to collect a sample for testing. Send it in, and your first report will serve as a base line. Keep sending in samples after each change interval, and monitor your metals report.

Quotes source post: 7650567

Autocrossing almost certainly stirred something up. A car and an engine are used a certain way for a while. I'm talking months, maybe years. The current or new owner decides to autocross the car or participate in a DE or track day or even visit a twisty road he's had his eye on for awhile. The car and engine are subject to loads and g-forces that they may not have ever been subjected too since day 1. Oil is thrown about with a vengence. And there's a lot of it being thrown about. An oil pump can output 60l (nearly 15 gallons which is nearly the capacity of the car's gas tank) of oil per minute. Under hard braking during cornering the engine's oil level in the sump will almost certainly drop some as oil is kept away from the scavage pumps (one side is worse than the other in this regard) and the oil in the sump moves around like it has never before. This action can stir up all sorts of "stuff" that had settled to the bottom of the engine oil sump and settled out in other "nooks" and "crannies" through the engine. Anything stirred up will be entrained with oil that is ingested by the oil pump. Of course everything the oil pump ingests gets pumped to the oil filter housing where the oil filter will of course catch it and in the oil filter housing it will stay until the oil/filter is changed. It is interesting to examine the oil from the housing. But what sometimes what someone sees can be a bit alarming. Almost always it is a false alarm. If you autocrossed the car and the engine's still together I daresay the IMS is not the source of that metal. I can't imagine an IMS sick enough to shed metal and yet be able to somehow withstand the rigors of auto-xing for any length of time. Sincerely, Macster.

Also it could be some remote chance its AL from when the new bearing was hammered in. What ever the case good luck with the car.

When I had my engine partially disassembled to fix a cracked head at 50,000 I took the pan off the bottom and found several flakes of metal. Never tested them to see if they were non-ferrous but as Macster said, such pieces are not uncommon, and could have been there since the engine was manufactured. I checked my IMS by puling off the flange, removing the tensioners, etc. and there was no excessive play. Also, the seals on the bearing were intact so if there had been deterioration it would have been trapped in the bearing. I did remove the outer seal based on the LN/Flat 6 recommendation and there were no signs of failure or any metal bits (unfortunately I did not install an LN bearing as I was not sure if the fix to the cracked head was going to work, I will be doing this in the future). By the way Charles at LN has recommended using a magnetic drain plug and keeping an eye on it for signs of metal now that the seal is off rather than going back in immediately to do the bearing upgrade. With the seal off any little bits of metal from the bearings and races would show up on the plug. However with only changing the oil every 5,000 there is some risk with this. When you say the IMS was "repaired" what does this mean. Other than replacing the flange, or installing a LN replacement bearing and flange, there is not much you can do to the IMS without splitting the cases. If the cases were split then a OEM bearing could have been put in, or a new IMS, or even the LN IMS upgrade. It would be good to know just what was done. And as Macster said, if the cases were split not doing new bearings would be unlikely (or just plain stupid).

Obviously you are concerned, but what if any recourse do you have if there is a wear issue with the motor? Do you have a warranty, can you give the car back, will the shop that did the repairs cover you and for what and how long? At this point, change the oil, if there was any damage done to the motor that hasn't been addressed and is on going, things will continue to wear and you will see metal next time as well. This could just be residual debris from the IMS failure. The only way to tell is a complete teardown and inspection, short of this, change the oil and filter, run it 500 miles, drop the filter, cut it open and take a look. If it looks good, get on with your life, if not put a new filter on run another 500 miles, same thing. If more metal is found, I think you have a problem, buy and extended warrant and keep driving or ??? Good luck

The metal will not always show up in the filter. In my case the flakes were in the pan, never made it to the filter. And if they are non -ferrous they won't stick to the magnet. However, for the IMS it is the ferrous bits that you want, or don't want to see. And to look at the drain plug you do have to drain the oil. I have used a 5 gallon bucket and put the oil back in when it only had 100 miles or so on it.

I just spoke with the shop that did the IMS repair. They stated that they did not go into the motor, only replaced the bearing from the rear. Having not done much work (only plugs and plug tubes, as noted about the leak) on the motor, I am not too familiar with how the repair occurs. I will continue to monitor the situation and see how things work. But since I did not have any noises or issues, I did autocross the car today and still no noises or issues (I would assume at least a knocking if I was loosing noteworthy bearing material. Hopefully the material is residual from the IMS bearing repair. I still need to get some pictures up and check if the material is ferrious. Thanks for all the info guys!!!