mklein9

Here is a twist that has us wondering what is going on. In Nov 2012 I bought a 2002 996 base model and had a PPI done. PPI showed metal in the oil filter and a leaking RMS and the seller kindly volunteered to pay for an LN Engineering IMS bearing and new RMS. I'm happy as I got a low mileage car with a fixed IMS/RMS for no additional expense.

Today, over a year, 12k miles, and 3 oil changes later, my mechanic finds metal bits in the oil filter. They are small (under 1 mm), magnetic, shiny silver, and quite a few of them (photo below). We popped the oil pan cover and the oil pan is completely clean. The engine starts up and runs without any clanking noise. I've already heard back from the shop that did the IMS replacement work and since the LN Engineering part uses ceramic bearings, they will not leave magnetic parts if they happen to fail. So it has to be something else.

Since I got the car, two oil changes showed a clean oil filter. After the last of those two oil changes, I had a good track day, and had installed racing pads and Pilot Super Sports so I know I was pushing G forces on the car that it had not had done to it before, and probably longer high RPMs than it been run before. Is it possible that some old pieces of the failing IMS bearing were being churned up and ended up caught by the filter?

Or is it something else entirely that is failing? My mechanic ran through a few other scenarios but none of them seemed to fit this type of metal particles.

In the end he said to drive it 1000 miles and come back in to inspect the oil filter to decide what to do next. He has seen lots of good and bad 996 engines and over the 17+ years I've been taking my P-cars to him has not steered me wrong.

KrazyK

Sorry Bro but theres your answer. I dont get it how people on here dont learn from others misery or at least read Jakes info before they do this.

And,,, if there were metal shavings before they replaced the bearing, it may have been too late. The engine should have been ensured to qualify for IMSB replacement before it was done.

halik

Err how would it be too late? The purpose of the oil filter is to filter the very exact material.


You very well may have picked up stuff that settled around the head pumps when you were pushing hard Gs. If there's nothing in the pan, I wouldn't worry too much about it.

Flat6 Innovations

The engine should have failed qualification if any debris was in the oil.

Material laden oil WILL take out the replacement IMSB and it will happen in a hurry, if the components shedding material doesn't break first.

Put simply, an engine with material laden oil should never be retrofitted until the course of the material is identified and corrective action is taken, with the oil system purged many times and short service intervals should always be part of that engine's future.

Shops are just throwing bearings in any engine, they don't give a damn- its not their technology.

DK570

Pretty sure it's a ceramic hybrid, the races are still steel.

kromdom

Contacted a local indy about getting my IMSB done in the near future: engine must be evaluated for retrofit suitability BEFORE simply upgrading. Having a medical background, this approach makes sense to me and agree with KK

EDIT: looks like JR already pointed this out

Flat6 Innovations

I instructed over 400 technicians all over N America in 2013 about this… But many simply did not listen, I even give absolute directives about what to do and what to do if you choose to retrofit anyway, and kill the warranty. Retrofitting an engine thats shedding material makes zero sense.

I turned down one earlier this week, packed it up and sent it home today. It was losing pistons.

KrazyK

Jake many are listening but few are willing to admit it.

Macster

Two oil/filter services with no metal trash and then one with and after a real hard track day with higher than before cornering and braking g-forces.

Going to have to guess some trash in the sump was stirred up and ingested by the oil pump through the pick up. The bits were smashed in the oil pump and caught by the filter. If something was coming apart I think your track day would have come to a premature end.

If the engine had trash in it when the IMSB was done I think the engine would have manifested problems before now.

Up to you what you do but you might listen to your mechanic and drive the car a while and check the filter again. 1000 miles seems rather high. I mean if you are really worried run the engine at idle until warm and then remove the oil filter housing and check for metal bits. If none the clean the housing and install a new filter and top up with oil and drive the car. I suspect the engine's fine -- no guarantees though of course -- but if at any time you hear scary noises shut off the engine ASAP and get the car to your tech on the back of a flat bed tow truck.

scorchpa

How does this apply to the IMS Guardian? Are you saying that once the guardian detects metal it's too late? Or is it that the first metal detected would be from the IMSB, but if metal detected is determined to be coming from the engine, then it is too late?

RDCR

Once the pistons start wearing/scoring the bore will one always have metal particulate showing up in the filter?

mklein9

Thanks for all the feedback.

I know there is a strong debate in these and other forums about LNE's conservatism, and that's fine, but that's not what I'm asking. I don't give a whit about what should have been done or didn't get done or whatever, that's all water under the bridge. I have a more pragmatic question: given what is known today about this engine, and the reality of financial constraints, what are the reasonable next steps? If I had $30k lying around, sure a top-quality rebuild would be a great option, but that's far from the case.

One poster has a medical background and mentioned his opinion. My background is engineering and I am tuned to finding a cost effective solution to difficult problems that are likely not well understood in entirety. I also know that getting to a failure rate of 0% or 1% or something that might be acceptable to an LNE is exorbitantly more expensive than getting to a failure rate of 10%, which might be more in the ballpark of acceptable to me for this case, i.e. the path I take from here might be wrong 10% of the time if I did it 100 or 1000 times. Since the engine will eventually fail and/or require a rebuild, of course hopefully 100k+ from here, that's perfectly fine.

A couple of other things:

1) Nobody has mentioned whether the flakes in the photo are in fact typical of a stock IMSB failure, and the magnitude (tiny amount, big amount, ...). Is there a typical appearance? Could this be something else? Especially considering a clean oil pan and two oil changes and 10k miles without any metal in the filter, and about 3k miles since the track day.

2) I've heard from two mechanics with a stake in this specific case, and they both say the same thing, which is it is unlikely to be a problem, but to check the filter after a little time. These are both experienced with IMS and its replacement and, maybe more importantly, know the history and current status of this engine. Which is not to say they are correct, but they are also making a cost-vs-benefit judgment.

3) I appreciate the responses from Jake (and Charles through a separate email). I understand their conservative viewpoint is appropriate for them and for LNE, but it is one of numerous valid viewpoints. Still, they've seen more cases than probably anyone outside the factory and dealer network, so they are important.

4) Macster's input is interesting that if there were a lot of junk floating around, the engine would likely have been toast already.

So at the moment I believe my next step is to drive it for a few hundred miles, inspect the oil housing and filter, and see if the info is different. What to do after that is not yet clear to me.

D6lc

Anything like this would scare the crap out of all of us, I still have the std bearing in at 45k, but still inspect my filter 3x a year ~1,500miles.
If I were in your shoes and the engine is running fine, I would run it for 50 miles and check the filter if ok then go to 250 miles and check, if that is ok then check it every 500 - 1,000 miles.
For the cost of the filters it’s either cheap peace of mind or you will very quickly see more debris and can make the decision what to do next.
Good luck, we all sincerely hope that this is a bizarre one off

KrazyK

No one can tell you what YOU should do. We can only give our opinions on what we would do.

I can tell you exactly what I would do. I would drop the engine and begin to disassamble it to check for damged/worn internals. Clean/repair/replace parts as needed. Install and be done.

Sorry to harp on this but if you DONT have mechanic ability why on earth buy a car that had metal in the oil in the first place? You are finding out the hard way, rebuilding the M96 aint cheap.

Ahsai

Are the flakes ferrous?