Disappointed to read the Tech Q&A
01-01-2012 | 12:13 PM
#91
Drifting
Joined: Aug 2006
Posts: 2,508
Likes: 24
It's important to observe the problem in the context of the history of Porsche engines. There have been issues with almost *all* Porsche six-cylinder engines from their design in 1965. Some highlights:
- Intermediate shaft wear in the 1969+ cases
- Magnesium case head stud pulling
- Chain tensioner failing (similar to the IMS failure in the amount of damage inflicted)
- Dilavar head studs snapping
- 3.6 valve guides wearing
To use the chain tensioner problem as an example - not all engines will have chain tensioners fail. But some did, and experienced some very severe failures. In the same manner, the IMS bearing failure is somewhat intermittent - some engines will fail and some will not, as evidenced by the facts. I myself have one car with 30K in my possession that had a complete IMS failure. On the other hand, I have another engine I tore down with about 110K on the clock with no detectable IMS wear. So, the bottomline is that it *may* happen to your engine, and if you wish to help minimize this particular failure mode, then there is a solution on the market. LN Engineering's kit contains the ceramic bearing and a new, redesigned end-plate for the bearing (probably the most robust option). Our kit (on the desk in front of me), simply contains a replacement bearing (same as the original), updated stud, and some specially designed spacers (expected price to be under $200). At this price point, I think it's quite reasonable to recommend that the bearing be replaced at each clutch replacement interval (or about 30-60K miles). That seems to be a safe bet for people looking to protect their engines from this failure. Also, keep your oil change intervals to under 5,000 miles.
-Wayne
- Intermediate shaft wear in the 1969+ cases
- Magnesium case head stud pulling
- Chain tensioner failing (similar to the IMS failure in the amount of damage inflicted)
- Dilavar head studs snapping
- 3.6 valve guides wearing
To use the chain tensioner problem as an example - not all engines will have chain tensioners fail. But some did, and experienced some very severe failures. In the same manner, the IMS bearing failure is somewhat intermittent - some engines will fail and some will not, as evidenced by the facts. I myself have one car with 30K in my possession that had a complete IMS failure. On the other hand, I have another engine I tore down with about 110K on the clock with no detectable IMS wear. So, the bottomline is that it *may* happen to your engine, and if you wish to help minimize this particular failure mode, then there is a solution on the market. LN Engineering's kit contains the ceramic bearing and a new, redesigned end-plate for the bearing (probably the most robust option). Our kit (on the desk in front of me), simply contains a replacement bearing (same as the original), updated stud, and some specially designed spacers (expected price to be under $200). At this price point, I think it's quite reasonable to recommend that the bearing be replaced at each clutch replacement interval (or about 30-60K miles). That seems to be a safe bet for people looking to protect their engines from this failure. Also, keep your oil change intervals to under 5,000 miles.
-Wayne
01-01-2012 | 08:43 PM
#92
Drifting
Joined: Sep 2011
Posts: 3,075
Likes: 22
From: Ephrata, PA, USA now. Originally from the UK
I am a new owner of a 99 C2 cab and have no history of any repairs or upgrades that the car might have had throughout its life. For my peace of mind re IMS bearing I change oil and cut open my filter. Mine is clean. No silver or plasctic bits or dust particles. I have a 45000 mile 3 year warranty on the car and should I see anything in the filter that should not be there, I will photograph it and give fair warning to the warranty firm of an impending engine failure. I think that phone call should wake them up into replacing the RMS bearing. The car has just completed 53000 miles. Its thanks to this forum and to the posters that I even found out about the 996 IMS bearing fault. I didnt know when I first bought the car. I have changed from Mobil 1 5w-40w to Motul 8100 excess 5W-40W since reading this forum and driving the car as though it was stolen. haha.
