Metal Flakes Found in Oil Filter

[ubii]

Well, I went and picked up my car this afternoon, after a week at the shop. The final bill was very painful, as it ended up being about $2K in parts and $3.4K in labor. Here is a list of the items that were installed or replaced, including several additional items which were found to be defective or which I requested to be installed.

1) LN Engineering IMS retrofit kit
2) clutch kit
3) flywheel bolts
4) RMS
5) chain tensioner paddle kit
6) camshaft seals
7) vario cam seals
8) AOS vent line
9) AOS bellows
10) spark plug seals
11) drive belt tensioner
12) accessory belt
13) RSS underdrive pulley
14) LN Engineering low temp thermostat
15) LN Engineering magnetic drain plug
16) oil filter

The following fluids were changed.

1) antifreeze
2) motor oil
3) power steering fluid
4) transmission fluid

About a third of the labor was associated with replacing the chain tensioner paddles, as they ended up pulling the engine. The IMS bearing did not look bad, there was wear on the external diameter of the bearing, but no real internal damage to the ball bearings or inner/outer races.

LN Engineering stated the following on their website, in regard to this external wear.

"Shown above are three used dual row bearings, all in good condition. A normal bearing shown at far right, as we would expect to find. Note two left bearings have wear on the outside diameter of the bearing. At best, we attribute this to tolerances in the manufacturing of the intermediate shaft itself, measured as ovality, taper, or any other variations that might allow a bearing to actually move and loose its press fit. It may be that part of the issue with failing IMS bearings are that the intermediate shafts themselves are not "all made equal", where some do not have the proper press-fit on the bearing or others do not have the bearings centered in the shaft!"

source: IMS

Even though the inner/outer seals appeared intact, the bearing itself was fairly difficult to turn. What was interesting is that 2/3 of the back side of the IMS flange was extremely pitted, which I am assuming is the metal debris that they found, when they removed the bearing. I will follow up with them to see if they took any photos, during the removal of the bearing, which included this metal debris. Listed below, is a link to photos that I took after I got home, of the chain tensioner paddles, the IMS flange, and the IMS bearing (both inside and out).

Photos

[san rensho]

Thanks for posting all the pics. One set of the chain paddles were really chewed up. Were they from bank 1 (backside of the motor)? Were you able to determine definitively where the metal came from?

You're set for good long time. Drive it hard and sleep easy.

[ubii]

Originally Posted by san rensho

Thanks for posting all the pics. One set of the chain paddles were really chewed up. Were they from bank 1 (backside of the motor)? Were you able to determine definitively where the metal came from?

You're set for good long time. Drive it hard and sleep easy.

My understanding is that inner (bottom) paddles on each bank (the two on the left, in the photo below), were the two that had the most damage.

https://lh3.googleusercontent.com/-lHxIHYjsyKg/TnAu_27PK9I/AAAAAAAAAAI/dRBvZMAC2rk/s800/IMG_0300.JPG

The link below from pelicanparts.com, shows both the outer (top) and inner (bottom) paddles, with the outer (top) paddle being the one closest to the person's hand.

http://www.pelicanparts.com/techarticles/Boxster_Tech/16-ENGINE-Camshaft_Swap_and_Chain_Tensioner/images_large/Pic10.jpg

The photo below, shows the outer (top) paddle on I believe bank 1 of my car, which did not have nearly as much damage as the two inner (bottom) paddles.

[ubii]

Originally Posted by san rensho

Thanks for posting all the pics. One set of the chain paddles were really chewed up. Were they from bank 1 (backside of the motor)? Were you able to determine definitively where the metal came from?

You're set for good long time. Drive it hard and sleep easy.

As for the metal flakes, I am still waiting for feedback from the shop, as to confirmation of their source. They did say that they found metal debris when they removed the IMS bearing and I am trying to see if they took photos of that or not. Not sure, but the metal flakes may have come from the pitting of the inner surface of the IMS flange and not directly from the IMS bearing itself, as seen in the photo below.

https://picasaweb.google.com/lh/photo/2q-Fifzb5G3SXWpA6rl4Bw?feat=directlink

[ubii]

I spoke with the shop this afternoon, their feeling is that the source of the metal flakes was the pitting of the inside surface of the IMS flange, as seen in the photos below. Nevertheless, I will continue to check the magnetic drain plug and oil filter, each time I change the oil.

[WhipE350]

Interesting! That is pitted for sure. You have pics of the bearing itself to see why it might have caused that pitting?

[ubii]

Originally Posted by WhipE350

Interesting! That is pitted for sure. You have pics of the bearing itself to see why it might have caused that pitting?

Yes, there are photos of the exterior and interior of the IMS bearing (which I completely disassembled) in the photo album below.

https://picasaweb.google.com/111981285973242271059/986?authuser=0&feat=directlink

The shop thought that the pitting may have been caused by excessive moisture in the engine due to infrequent oil changes made by the previous owners. No pitting was seen on the IMS bearing nor on any other internal engine component, only the inside surface of the IMS flange. The exterior of the IMS bearing did show a bit of wear, which may have been caused by it loosing its press fit, as explained in one of my previous posts. Other than that, the bearing appeared to be in pretty decent shape, though it was fairly difficult to turn by hand.

[WhipE350]

Wow thanks for the great pics. A few thoughts - the chain tensioner had a bunch of wear, I really wonder why one car has this and another doesn't. One would think it might be the variation in the quality of the tensioners. It isn't clear what could have caused that pitting, the IMS looks like it was perfect...other then over time oil had forced its way in and mixed with the grease.

Thanks again.