Poll, Condition of my IMS bearing - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Pominoz · 09-21-2014, 08:42 PM

Hi Everybody,

Ok I've decided to get my IMS bearing replaced with an LN Engineering retrofit. My car is a 2002 base (2.7) manual with 85K Kilometres on the clock (56K miles approx.)

I've only just got the car, and it is in great condition with nothing apparently wrong with the engine. There are no funny noises, the engine is strong, and I had a PPI done. However, the previous owner did the bare minimum of oil changes. I've just had it serviced, but the last oil change was about 4 years ago, at about 65K kilometres. Not ideal really.

Anyway, please place your bets on what condition my old IMS bearing will be in when I have it replaced on Friday!

Porsche9 · 09-21-2014, 09:38 PM

If it's not perfect the engine is already in trouble.

Pominoz · 09-21-2014, 10:06 PM

Quote:

Originally Posted by Porsche9

If it's not perfect the engine is already in trouble.

Three guesses what condition I'm hoping it's in

JFP in PA · 09-22-2014, 02:37 AM

.................

kjc2050 · 09-22-2014, 03:11 AM

More Forum clutter.

Pominoz · 09-22-2014, 03:53 AM

Quote:

Originally Posted by kjc2050

More Forum clutter.

Sorry you feel like that. It's just meant to be a bit of fun, possibly at my expense if it turns out to be bad news.

Cheers anyway.

Giller · 09-22-2014, 05:46 AM

Quote:

Originally Posted by Pominoz

Sorry you feel like that. It's just meant to be a bit of fun, possibly at my expense if it turns out to be bad news.

Cheers anyway.

Ah, don't sweat it. Personally, to me, the whole point of these forums is to talk about our cars, whether we are sharing/asking technical questions or we just want to share a funny story or anecdote. Forums are open-concept (except for cats!) and all are free to share thoughts, ideas and yes, silly fun.

thstone · 09-22-2014, 07:15 AM

My IMSB was in perfect shape after 136,000 miles and 89 track days. Instead, lifter failure was caused the engine to fail. Best of luck but odds are very high that if your bearing had a problem, you'd already know it.

Perfectlap · 09-22-2014, 07:37 AM

you say the bare minimum of oil changes were done? How many?

Another factor is how often was the car driven. a 12 year old car that saw about 4,500 miles might be good if the mileage came in somewhat frequent and year round trips. Not so great if they came from mostly summer time driving without having the oil changed after the driving season.

Did your PPI include a leak down test? That will tell you more (engine wise) than a visual inspection of just the IMS bearing, which really needs to taken apart to see what's doing (by someone who knows what to look for).

BoxsterPHD · 09-22-2014, 08:41 AM

I would bet that it's probably in pretty good shape. I just had the retrofit LN bearing done a couple of days ago. My car is a 2001 2.7 and the previous owner had only done one oil change in 3 years. The car has done 36K miles. Here's the old bearing:

I couldn't find any visible signs of scoring. Yours will probably look the same. However, the seals had leaked and there was no grease left inside, but at least it was well lubed by engine oil.

Hope you can post some pics of your old bearing when the job's done.

Jake Raby · 09-22-2014, 08:43 AM

If the tube was filled with oil and the seals compromised, then the bearing was at Stage II failure. Looks like it was caught at the perfect time, before wear increased and contaminated the oil supply. Once that happens, the health of the retrofitted bearing is seriously impacted.

epapp · 09-22-2014, 08:54 AM

I suppose the grease being washed out could be a 'stage' of failure, but if the bearing has engine oil to lubricate it, whats wrong with being in 'stage 2' failure for 150,000 miles?

woodsman · 09-22-2014, 10:21 AM

That all depends on how fast the bearing progresses through the phases of destruction and if the bearing was designed for grease oil is a poor substitute. You haven't read much about this issue have you?

epapp · 09-22-2014, 11:47 AM

Considering the DOF fix uses oil to lubricate the bearing, I would think oil as a substitute is just fine

And my point was, the bearing destruction wouldn't progress very quickly if it had oil around it to lubricate it...

Pominoz · 09-22-2014, 04:56 PM

Quote:

Originally Posted by BoxsterPHD

I would bet that it's probably in pretty good shape. I just had the retrofit LN bearing done a couple of days ago. My car is a 2001 2.7 and the previous owner had only done one oil change in 3 years. The car has done 36K miles.

Hi, I think you are likely correct. I'm sort of expecting, and hoping my bearing will be no worse than yours. It's going to be interesting to find out.
I'm going to take some pics of the old bearing.

Cheers!

Pominoz · 09-22-2014, 05:02 PM

Quote:

Originally Posted by Perfectlap

you say the bare minimum of oil changes were done? How many?

Another factor is how often was the car driven. a 12 year old car that saw about 4,500 miles might be good if the mileage came in somewhat frequent and year round trips. Not so great if they came from mostly summer time driving without having the oil changed after the driving season.

Did your PPI include a leak down test? That will tell you more (engine wise) than a visual inspection of just the IMS bearing, which really needs to taken apart to see what's doing (by someone who knows what to look for).

Hi, from the service history it looks like the car has only had 4 oil changes in it's life. The previous owner used 20K kilometres as his oil change limit, not the number of years. That's why it was a 4 year gap between the most recent oil changes. If the theories about leaving 'old' oil in the engine are correct then I might be in trouble :-)

On the PPI they did a compression test, not a leak down test as far as I know.
The compression test has 4 cylinders down 4% and 2 cylinders down 6% which isn't too bad I think.

Cheers.

Pominoz · 09-22-2014, 10:57 PM

Quote:

Originally Posted by thstone

My IMSB was in perfect shape after 136,000 miles and 89 track days. Instead, lifter failure was caused the engine to fail. Best of luck but odds are very high that if your bearing had a problem, you'd already know it.

Thanks for that, I'm keeping everything crossed!

One more factoid I forgot to mention, it's only ever had Mobil1 0w40 oil from new.

I know there are different opinions again on the best engine oil with some people going for higher viscosity. I know nothing about oil, but my hunch is that you'd be better off with lower viscosity in an IMS bearing with the grease washed out, assuming that the worst wear is happening on engine start up. Having said that, I don't think the longevity of the bearing is likely to be down to one thing. We'll probably never know.

Cheers!

roux · 09-23-2014, 12:33 AM

Not bad as it really need to replace.

Perfectlap · 09-23-2014, 08:26 AM

Quote:

Originally Posted by Pominoz

Hi, from the service history it looks like the car has only had 4 oil changes in it's life. The previous owner used 20K kilometres as his oil change limit, not the number of years. That's why it was a 4 year gap between the most recent oil changes. If the theories about leaving 'old' oil in the engine are correct then I might be in trouble :-)

On the PPI they did a compression test, not a leak down test as far as I know.
The compression test has 4 cylinders down 4% and 2 cylinders down 6% which isn't too bad I think.

Cheers.

4 oil changes in 55k miles? That's well beyond the limit of a mass market oil like Mobil 1. I would get a sample of your oil after 4K miles and send to Blackstone Labs for one of those simple oil analysis. Then move to a more expensive oil like Motul Xcess 8100 or Joe Gibbs DT40 and use a spin on oil filter, which makes sure you're only using filtered oil at all times. Do a second oil analysis after a few oil changes. And make sure you let the egine warm up with a good 20 minutes of driving before you start laying into the higher RPMs. Best to take it easy until you have better sense of the impact of such long stints with old oil.
Or ignore all of the above and roll the dice. It's kind of like investing in stocks, some people sleep fine others check the computer every 5 minutes.

Pominoz · 09-23-2014, 02:20 PM

Quote:

Originally Posted by Perfectlap

4 oil changes in 55k miles? That's well beyond the limit of a mass market oil like Mobil 1..

I don't know why the previous owner left it quite so long between oil changes, especially as he's a designer for a car company. I'm going to change the oil between services myself, and generally look after the engine as I intend to keep the car..
Assuming nothing serious is uncovered on Friday then I'll be reasonably confident about the engine going forward.