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Alas, time for my '99 986 to go into hibernation ... for 6 months no less. Had the oil changed out and cut up the oil filter to read the tea leaves. Catchment is pretty much the same as last several years ... nothing out of the ordinary. A few black metal fragments and some non-metallic bits ... likely variocam chain pad wear products. The car will reach the 90K mile service interval next spring ... about 1000 miles to go. Thinking I might have the cam timing and deviation checked then to see if the pad wear is becoming excessive. The top group of black particles appears to be metallic fragments and the bottom group of reddish brown particles are the suspect variocam chain pad wear products. Any idea what the source of the small black metallic fragments might be?

PS: I don't have an aftermarket magnetic drain plug ... thinking perhaps I really should install one? Do these plugs use the standard Porsche plug washer ... something the dealer would have when doing the oil and filter change? I'm sticking with Mobil 0W40 oil. My dual row LN retrofit bearing has 22000 miles and 7 summers of non-track back roads touring usage. When the original bearing came out in 2010 at 67000 miles ... it appeared to be in serviceable condition ... no issues other than a lack of grease behind the front cover which I removed for inspection.

I used to pull apart my filter every or every other change, and look inside.
Lots of shiny specs at first met the eye in the folds of the pleating , BTU they almost always turned out to be nothing more than oil bubbles.

I never recall seeing particles of metal ,plastic etc. And when i pulled my motor apart the plastic parts were all intact. The aftermarket (LNE) IMS bearing, on the other hand, was in awful shape with tons of wear on the races from the much harder ceramic balls.

So this meant either a) the parts were very, very smalll or b) i missed them (or c), both).

I do wonder if varnish or carbon could form small particles.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com
Fortunately, I've never seen any shiny fine particles in the filter since installing the LN IMS bearing so hopefully, all is well with the races. The fact that the hard black fragments are not bright/shiny and don't have any ground surfaces hopefully means the source is not a bearing.
If you are going to cut open the filter element you probably should capture a sample of oil to have analyzed. Also, you should dump the oil filter housing oil into a *clean* drain pan. You want to see what was caught by the filter but not captured/held in the filter elements.

What you are looking for is are the bits of metal just pieces of debris that that got dislodged due to the g-forces of tracking coupled with the extra violence oil get slung around in the engine or is the engine shedding metal from somewhere and is it going through the oil pump and getting pulverized to the point it shows up as a high PPM count of some kind of metal (bearing or just something ferrous)?

The installation of the aftermarket IMSB has probably as a side effect of the installation opened up the hollow void of the IMS that is behind the IMSB and who knows what bits of trash could have ended up in this backwater spot and are now over time being washed out and into the engine's oil supply?

The plastic bits are tiny pieces of chain guide composite plastic. The plastic is tough but the rigors of tracking with the very high chain speeds and rapid changes in engine RPMs really put extra stress on these. That the rails shed a few tiny bits of plastic material is not surprising. Over some time the plastic rails will wear out. Well, before they wear out down to the aluminum at some point the plastic material will get too thin and fracture/break up. But when this will occur no one can say. Only if you are very lucky will the signs of pending break up be visible in the oil filter or oil filter housing oil.

If you pour the oil filter housing oil out into a clean pan and the oil has the sheen, even if faint, of metal flake that's probably from at least one chain in partial contact with the aluminum guide rail underneath (the now missing) plastic guide. But the engine ain't there yet.

About all you can do is just show up at every track session with fresh engine oil and a new filter unless you want to rebuild the engine with track modifications to hopefully give it a longer service life even with the rigors of tracking. You still need to show up with fresh engine oil/new filter though.
If so, I never had any visible particles in my oil (cant really tell now), and I don't have the aftermarket IMS-B anymore, nor do i have an oil filter I can (easily) cut open any more :-) PArt of moving to the oiled journal bearing is an adapter that requries a spin-on metal can OF. Which i dont like as well. All gone after the rebuild last winter. I do UOA. Its quite amazing what one learns - mostly that the preponderance of oil advice is wrong. e.g.: my oil's shear down for the "hot" viscosity is nearly nil, dilution - one of the supposed killers of track and race car oil, is unmeasurable, and additives are near the levels specified on the back of the bottle. Basically i could leave it in forever (well, longer, much).

For note -this was with Mobil 1 15w50, mostly for the high HTHS (> 4.5) and the 1300ppm zinc for barrier lubrication (last ditch protection)

I do have some high chromium - which pretty must has to be rings - which may or may not indicate an issue. Runs great though.

My IMS-B is now an oiled journal bearing. Done when the motor was out for Nickasil liners.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com
Grant, you bring up an interesting point - that your oil shows very little dilution. That stands to reason since most of your driving seems to involve longer periods of time, resulting in warm / hot engine where the diluents are probably burned off. I'm sure if you did a lot of short trips, you'd find a higher concentration of dilution in the oil.
Precisely.
grant - 6 years ago
but it amazing how many experts will tell you that racing will result in high dilution from rich conditions. Bo-o-o-gus :-) ( and click and clack would have said)

Grant

gee-lenahan-at-gee-mail-dot-com
Many thanks for the useful comments. I don't track my car and just about every time it goes out for a run, the engine winds up being thoroughly heat soaked. I'll try to have the dealer let me have a look at the oil from the filter housing this time next year. Where can I get an oil analysis done up here in Quebec?

PS: Re hibernation ... I don't start my engine during the winter. The RMS seal was replaced when the LN IMSB was installed and I've not had any leaks with the car static for the better part of six months every year since 2010.

Covered bridge in Wakefield, QC

$2.50 by mail they send you sample containers. $25/shot.

G

Grant

gee-lenahan-at-gee-mail-dot-com
Quote
grant
If so, I never had any visible particles in my oil (cant really tell now), and I don't have the aftermarket IMS-B anymore, nor do i have an oil filter I can (easily) cut open any more :-) PArt of moving to the oiled journal bearing is an adapter that requries a spin-on metal can OF. Which i dont like as well. All gone after the rebuild last winter. I do UOA. Its quite amazing what one learns - mostly that the preponderance of oil advice is wrong. e.g.: my oil's shear down for the "hot" viscosity is nearly nil, dilution - one of the supposed killers of track and race car oil, is unmeasurable, and additives are near the levels specified on the back of the bottle. Basically i could leave it in forever (well, longer, much).

For note -this was with Mobil 1 15w50, mostly for the high HTHS (> 4.5) and the 1300ppm zinc for barrier lubrication (last ditch protection)

I do have some high chromium - which pretty must has to be rings - which may or may not indicate an issue. Runs great though.

My IMS-B is now an oiled journal bearing. Done when the motor was out for Nickasil liners.

Grant

No it was targeted/intended as a response/comment to the OP.

As for most oil advice is wrong I note that you in your comments appear to add to this wrong oil advice. You use 15w-50 and appear to tout this. This is contrary to Porsche as 15w-50 is not on its approved oil list. While this oil might deliver an acceptable UOA given your situation what about someone who drives thousands of miles on the street in all kinds of weather then decides he wants to play on the track? My advice is to show up at at the track with fresh oil.

I'm not done yet.

I recall one owner of an air-cooled 911 mentioned he used 15w-50 in his car's engine fpr both street and track use even though the heavier oil based on his monitoring reduced MPG on the street. This was due to the increase in friction of this oil compared to 0w40. I thought it nice of him to give other trackers an edge by using an oil that increaed engine friction and made his car run slower than it would otherwise.

In your case that 15w50 might not be doing as good of a job as you think. That the ring wear might be due to the poor oil flow of the 15w-50 at start up. Or at other times. The higher molecular friction of the oil may increase oil temperatures in some areas of the engine and at high RPMs in the small space between the rings and the cylinder walls where the oil film can be just a few oil molecules thick the oil might be breaking down.

There's a reason 15w-50 oil is not approved by Porsche, the only real authority on oil for its engines. You might be learning the hard way why.
at 230 degrees, 15w50's viscosity chart shows it to be well below where 0w40 is at more modest temperatures, such as 180deg so.
...99% of the use on this car is at quite high temperatures. Also, 20w50 was recommended for these motors during 2000 - 2003 for hot weather (presumably hot operating temps). Its in my manual, and likely yours (your car is old right?)

That said, I actually am a fan of oil that flows quickly and easily, subject to a high film strength. For any car that sees mixed use its clearly the way to go - in fact 5w30 may >>. 5w40 since the base stock has fewer compromises asked of it. I have been doing some reading recently that calls into question the correlation between viscosity and film strength, and the correlation between HTHS and film strength. If that correlation is not consistent, then I'd agree. At the moment i use what is suggested by two guys I race with, one who work's in and the 2nd at . Yet their recommendations are subject to the same ASTM assumptions I am questioning...

I actually plan to do UOA tests with the A40 oil that has the highest specified film strength.

Grant

gee-lenahan-at-gee-mail-dot-com
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