IMS Failure - Newbie information

[mike597]

1 hour ago, edc said:

I've never really read of anybody using it. £565+VAT on Design911. I guess not much change out of £1500 or more of doing a clutch too. 

Exactly 

[½cwt]

3 hours ago, topradio said:

@Cheddar Bob I'm confused.  You have an oil leak and that has been diagnosed as an IMS (intermediate shaft bearing failure)?

Normally when the IMS lets go it grenades the engine or at the very least starts making a noise and you might catch it before it causes total engine failure.

An oil leak is often caused by a RMS (rear main seal) failure.

Do you have both?

Edit to say, an oil leak on a potential purchase wouldn't necessarily cause me to walk away

If you read all of @Cheddar Bob's oil leak posting it appears that he has been very lucky to have discovered the oil leak and trace it back with Lee at CPS to what must be the outer seal of in the IMS bearing which must have a failed inner seal as well.  If this is a pointer to look out for for owners it has to be useful info, as the RMS leas are usually slower and so don't drip pools of oil in the same way.

Guys, this thread is not opening up a debate on this topic of IMS vs RMS vs .... something else leaking again but a fortunate identification of the IMS failing but not yet failed enough to trash the motor.  The moral seems to be check for leaks and they possibly have different characteristics for IMS and RMS.

[edc]

47 minutes ago, mike597 said:

Exactly 

RPM? Have you asked them how many they've fitted and over how many miles or years have they seen these cars? 

[Cheddar Bob]

Thanks all for your contributions. I wasn't however intending this thread to be a discussion over what fault I might have. I know what the fault is from a specialist and trusted diagnosis. 

I'll find out shortly if it's end ex or fixable.

What I was hoping to achieve is let new buyers know that the panic about IMS is out there and things to look out for is as I suggested. 

Some of the replies suggest my comments haven't been fully read or understood. 

I have a car with a real example of IMS failure. The symptoms of such have been signs of that failure over a period. 

If this thread helps others catch it quicker or notice it then that's a good thing. 

 

Regarding the dealership. All quiet from him. I will however follow up from my efforts of contact. I'm aware of my obligations as well as the dealers. I get the impression some will hope the problem will go away rather than respond. I'll update how that pans out also. 

 

Thanks again for the comments. 

 

 

[edc]

5 hours ago, Araf said:

Fair enough.  In that case, how was a dealer to know the IMS was weeping and not the RMS - which is a common 986 trait?  Don't beat yourself up, there's no way that you could have known the IMS was failing either.  I also wouldn't discount a perfectly good car in other respects.  Investigate if necessary but don't discount it. 🙂 

It's debatable whether any car dealer would know if there was a slow burn IMS related problem. The cars is a 2003 so could have been wearing to a point of failure for 17 years. You could say the same for say a water pump or an expansion tanks that eventually cracks. 

If they see oil, do you really expect them to remove the gearbox? If they are a general car dealer do they even know what an IMS is? They might degrease and clean, run it for a couple of weeks and see not a lot. A bit like a CEL coming on and using the OBD tool to clear it and run the car for a couple of days. 

[Berni29]

Hi

For the IMS assembly it looks to me like there are 3 main places they can leak. One is through the bolts which hold the cover on. The holes go straight through into the crankcase so oil can travel up the threads and out. Then there is the large rubber "O" ring which goes around the IMS cover. This was updated to make leaks less likely. Then there is a small "O" ring on the spindle itself. Oil can get past that and out of the spindle nut.

I guess if the bearing is on the way out and is vibrating the assembly then all three must be more likely to leak.

I think the message is that dripping oil from that area needs investigating. 

Berni

[Shazbot]

I do wonder how many cars have had a perfectly good replaced IMSB , replaced powered by the fear of IMS failure. I know they are seen by some specialists as to be replaced at the same time as a clutch but I've seen clutch life as quoted at 50k by the same places.

 

 

[edc]

37 minutes ago, Shazbot said:

I do wonder how many cars have had a perfectly good replaced IMSB , replaced powered by the fear of IMS failure. I know they are seen by some specialists as to be replaced at the same time as a clutch but I've seen clutch life as quoted at 50k by the same places.

 

 

You'd be unlucky to need two clutch changes in 100k and probably in a country unique situation of having had 2 IMS bearing changes within 100k. You would either be so cautious that you shouldn't have bought a 986 in the first place or completely had over by your indy. 

My own car had a clutch and IMS change in 2013. The original was in ok shape. 

It is somewhat of a catch22. If you need a clutch change that is the perfect opportunity to inspect and replace if wanted the IMS bearing. If you just want an IMS visual inspection then you will lay lots of labour to remove the gearbox and clutch. If you have no inspection or change then you are into the realms of waiting for symptoms by and large which it is too late and the costs are another factor higher than an IMS bearing change in itself. This is not the same as saying shall I replace the water pump or not as if that goes you (mostly) just replace and carry on. 

Knowing what I know now if I needed a clutch change I would possibly not have the IMS changed if everything in that area was squeaky clean and the cam deviation was perfect. 

[kevs]

It would be really interesting to hear what IMSB they find when they open it up - an original or an aftermarket one.

I’m at 55k miles and the clutch it still nice and light so not feeling like I want to change my IMSB.  My Indy (Porschacare) swears by the EPS one.

[edc]

1 hour ago, kevs said:

It would be really interesting to hear what IMSB they find when they open it up - an original or an aftermarket one.

I’m at 55k miles and the clutch it still nice and light so not feeling like I want to change my IMSB.  My Indy (Porschacare) swears by the EPS one.

Why do they swear by it? What gives then the confidence it is better than others? I can only presume they think it is better because if it is their favoured option and/or they don't offer other solutions there must be a reason. What data have they got showing the EPS is the best? 

I'm curious to understand the reasonings behind the choices the Indy's make.

[kevs]

10 minutes ago, edc said:

Why do they swear by it? What gives then the confidence it is better than others? I can only presume they think it is better because if it is their favoured option and/or they don't offer other solutions there must be a reason. What data have they got showing the EPS is the best? 

Said he has seen a number of LN Engineering IMSBs come in failing and never had any EPS failures.  Of course it could be because it is his preferred option (he would no doubt argue it’s his preferred option for a reason!).  

I didn’t grill him on it though as I didn’t intend to fit one and he wasn’t pushing it, I just asked him what he thought.  He said it’s a low risk.  That’s all I can add, I’m afraid. 

[villaman]

21 hours ago, K.I.T.T. said:

There are a number of specialist who actually advise against swapping out the bearing, if it's fine, and will talk you out of doing it as a precaution - it was never designed to be replaced without splitting the crankcase - although it is possible on pre 2006 cars. Believe Lee at CPS actually talked @villaman out of replacing the one on his 997.

Do your research, pay your money, take your chances. There isn't a one size fits all solution.

Engine problems exist among a number of marques. Go and read about BMW S65 / S85 engines.

Yes this is correct. I discussed last year with Lee @ CPS whether or not I should replace the IMS bearing when the car was in for its annual pre-season service. 

Lee essentially advised that as the car had done 130K and was not exhibiting any symptoms then to leave the original in situ....(another example of Lee's integrity !!).

@Cheddar Bob If this had happened to me i would look at the positives. I appreciate that there is now the unexpected expense of having to replace the IMS, but it could be significantly worse as if I've understood the thread correctly, you've caught it before the inevitable catastrophic engine failure. You could having being looking at a write off.

[edc]

I've also heard third hand on forums that LN bearings have failed. LN always seem to attribute this to bad installation or installation into an already bad engine. 

The question is sample size and reliability of data. How many LN bearings have been fitted? Lots, so is what is the proportion of failure to success? For the EPS, I rarely if ever see anyone writing that they have one fitted, so the argument follows the installed base is a lot lower hence the lack of failure data. 

[kevs]

Completely agree which is why I am keen to see whether it’s an original IMSB or not when Lee gets it out.

In a way, it’s a good job my clutch doesn’t need changing as it would be a big dilemma.

[mike597]

Yes I was surprised my indy recommended eps as I'd only really  heard of the LN being used in any significant numbers.

[Boxstercol]

3 minutes ago, edc said:

I've also heard third hand on forums that LN bearings have failed. LN always seem to attribute this to bad installation or installation into an already bad engine. 

The question is sample size and reliability of data. How many LN bearings have been fitted? Lots, so is what is the proportion of failure to success? For the EPS, I rarely if ever see anyone writing that they have one fitted, so the argument follows the installed base is a lot lower hence the lack of failure data. 

Agreed.

LN also have a ‘life’ on their bearings for replacement, if I remember correctly it’s an advised change at 40k miles. Can’t be that great a solution when you’ve got to consider it a serviceable item. 
 

Dunno if I’ve missed something here as I’ve only scanned the thread, but since when has an oil leak been diagnosed as an IMS failure? I was under the impression that you got little, if any, warning of a failure with IMS bearing.

[edc]

19 minutes ago, Boxstercol said:

Agreed.

LN also have a ‘life’ on their bearings for replacement, if I remember correctly it’s an advised change at 40k miles. Can’t be that great a solution when you’ve got to consider it a serviceable item. 
 

Dunno if I’ve missed something here as I’ve only scanned the thread, but since when has an oil leak been diagnosed as an IMS failure? I was under the impression that you got little, if any, warning of a failure with IMS bearing.

It's important to look at the context. LN is a US company and their biggest product is as a result of a corporate class action. In the US these sorts of claims and liability issues are quite different to perhaps UK and Europe. 

Manufacturers like Porsche or LN don't specify replacement intervals for these bearings but not do they do so for wheel bearings, clutch release bearings, water pump bearings, or other items like suspension arms. 

[topradio]

21 minutes ago, Boxstercol said:

Dunno if I’ve missed something here as I’ve only scanned the thread, but since when has an oil leak been diagnosed as an IMS failure? I was under the impression that you got little, if any, warning of a failure with IMS bearing.

Yes, that's confusing me as well.

[kevs]

13 minutes ago, topradio said:

Yes, that's confusing me as well.

OP clarified further down in the thread that it’s been diagnosed as an IMS failure

[topradio]

1 minute ago, kevs said:

OP clarified further down in the thread that it’s been diagnosed as an IMS failure

I know! But since when was an oil leak a symptom of impending IMS failure?

As @Boxstercol says above, the received wisdom is that there is no warning of the IMS bearing letting go.

[PaulQ]

2 minutes ago, kevs said:

OP clarified further down in the thread that it’s been diagnosed as an IMS failure

Because of metal in the oil, not an oil leak. 

[topradio]

4 minutes ago, PaulQ said:

Because of metal in the oil, not an oil leak. 

He never said that he had metal in the oil, just that the specialist said that that's one of the symptoms.  The op inferred that an oil leak was a symptom of impending IMS bearing failure.

[kevs]

18 minutes ago, topradio said:

I know! But since when was an oil leak a symptom of impending IMS failure?

As @Boxstercol says above, the received wisdom is that there is no warning of the IMS bearing letting go.

Wow, sorry I misinterpreted your questions the post you linked said they had only skimmed the thread.  I can see IMS debates going the same way they always have 😂.

[PaulQ]

6 minutes ago, topradio said:

He never said that he had metal in the oil, just that the specialist said that that's one of the symptoms.  The op inferred that an oil leak was a symptom of impending IMS bearing failure.

Ah right. I was sure he said there was. 

Might have been on his other thread. 

 

[kevs]

Mine has never left a spot on the garage floor and certainly nothing like OP showed.