Jump to content

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

RMS failure, 10 days out of warranty


Recommended Posts

I took my 07 997 in for regular scheduled maintenance. Technician found that the RMS was leaking. I am 10 days out of warranty. Only 25k miles and always serviced by Porsche.

I have opened a customer assist case with Porsche. Any idea on my chances of getting this covered or your personal experiences?

Link to comment
Share on other sites

I took my 07 997 in for regular scheduled maintenance. Technician found that the RMS was leaking. I am 10 days out of warranty. Only 25k miles and always serviced by Porsche.

I have opened a customer assist case with Porsche. Any idea on my chances of getting this covered or your personal experiences?

How did the tech diagnose the RMS?

Was the transmission removed to make a positive diagnosis as opposed to the IMS flange/bearing?

Regards, Maurice.

Link to comment
Share on other sites

I don't think the transmission was removed.

I have read about the IMS problem being more prevalent in the MY05/06 or older. Are there any other symptoms besides oil leak at the eng/tran mount?

If my case is approved should I pay to have the IMS bearing replaced?

Also, is replacing the clutch disk a preventative measure? I like the idea.

Link to comment
Share on other sites

I don't think the transmission was removed.

I have read about the IMS problem being more prevalent in the MY05/06 or older. Are there any other symptoms besides oil leak at the eng/tran mount?

If my case is approved should I pay to have the IMS bearing replaced?

Also, is replacing the clutch disk a preventative measure? I like the idea.

J:

If the transmission was not removed, AFAIK there is no positive way to tell whether a leak is coming from the RMS or the IMS because they are essentially lined up vertically with the RMS in the center of the engine and the IMS lower down.

Sometimes there will be a strong smell of rancid oil if the oil is coming from an IMS problem.

If you have a Durametric or a PST2 or PIWIS, you can monitor the cam position sensors for deviations. If the deviation between the two camshafts

remains steady at idle and does not fluctuate or bounce around, that is one indication that your IMS bearing is in good shape.

You are correct that the general consensus is that the problem is more prevalent and well-known with 2005-06 and older M96 engines, but that may be because of the age and mileage of those cars. You can only be 100% certain that your IMS will not blow if there is no IMS in the engine, which Porsche designed out of the engine in 2009, IIRC.

Also, AFAIK, there is no possibility to retrofit an IMS bearing, whether OEM or LN Engineering version without splitting the case apart in the 2006 and later M96 engines. At the very least, make sure that the IMS flange is removed to inspect the condition of the IMS.

As to the clutch disc replacement, that is a much easier situation to evaluate, this time based on whether or not the leaking oil has contaminated the surface (and, of course, how worn it is due to mileage/and or driving style).

Keep us posted on how you make out.

Regards, Maurice.

Link to comment
Share on other sites

  • Moderators

bummer. hope the dealer won't charge you for the rms repair. May want to call LN engineering for IMS kit while you are doing the RMS replacement. Heard the IMS kit for the M97 engine 997 is available. Good luck

The LN IMS kit for 06 and later M97 engines require complete disassembly of the engine to install. From late 05 on, the M97 used a rear IMS bearing that is larger than the opening in the cases, so it cannot be removed with the engine assembled.............

Edited by JFP in PA
Link to comment
Share on other sites

Maurice, (and all)....

Thanks for the advice.

Good news! Porsche approved the RMS replacement.

Will they be able to tell once they break the trans from the engine if this is an RMS vs IMS failure?

If so, I will alert them to do so.

I'm concerned as why an engine, driven light to moderate, would have such a failure at 25k miles. I'm hoping it is a lack of use that has caused the RMS to go bad. The car will sit for several weeks at a time.

If it is an IMS failure, what is the best remedy?

If I have a MY07, does this mean I have the larger IMS bearing already?

I will evaluate clutch replacement/TO bearing after they get it apart (unless this group is suggesting replace them anyway). These will be on my dime if I decide to replace them.

Thoughts?

Link to comment
Share on other sites

  • Moderators

Maurice, (and all)....

Thanks for the advice.

Good news! Porsche approved the RMS replacement.

Will they be able to tell once they break the trans from the engine if this is an RMS vs IMS failure?

If so, I will alert them to do so.

I'm concerned as why an engine, driven light to moderate, would have such a failure at 25k miles. I'm hoping it is a lack of use that has caused the RMS to go bad. The car will sit for several weeks at a time.

If it is an IMS failure, what is the best remedy?

If I have a MY07, does this mean I have the larger IMS bearing already?

I will evaluate clutch replacement/TO bearing after they get it apart (unless this group is suggesting replace them anyway). These will be on my dime if I decide to replace them.

Thoughts?

First, if you had an IMS failure, you would be needing a new engine as this one would be a boat anchor. Secondly, yes, you have the “final revision” IMS bearing, which cannot be replaced without totally dismantling the engine. LN does have a replacement for it, but it still requires taking the engine apart….

Link to comment
Share on other sites

  • Admin

These cars are made to be driven. A mechanic told me that cars that sit have more

problems. I suggest you spend more time driving your car once it is repaired.

Paul

That statement is not true. Only cars that sit for very long periods of time where the seals dry up, moisture gets into the car, and/or they get attacked by rodents have "sitting" problems.

My RMS leaks about 2 drops per week in the summer and stops in the winter as the seal expands with the temperature. Certainly not worth the trouble to replace IMHO.

Link to comment
Share on other sites

These cars are made to be driven. A mechanic told me that cars that sit have more

problems. I suggest you spend more time driving your car once it is repaired.

Paul

That statement is not true. Only cars that sit for very long periods of time where the seals dry up, moisture gets into the car, and/or they get attacked by rodents have "sitting" problems.

My RMS leaks about 2 drops per week in the summer and stops in the winter as the seal expands with the temperature. Certainly not worth the trouble to replace IMHO.

This statement was made by a Porsche mechanic. It was his observation that

cars that sit around tend to need fixing.

This is not my statement.

Paul

Link to comment
Share on other sites

  • Moderators

There is very little rhyme or reason as to why or when the RMS is going to leak in these cars. Some seem to go on forever with the factory seal, others start to leak. How much the car is driven, or even how it is driven, does not seem to matter. The only single “factoid” we have been able to identify as correlating to RMS leaks is oil weight; those using 0W-40 oils suffer more leaks than those using 10W-40 oils. We have also noted cars with very slight RMS leaks using 0W-40 oil stopped leaking when switched to 10W-40 oil; but that does not work on cars with severely leaking RMS…………

Link to comment
Share on other sites

  • Admin

These cars are made to be driven. A mechanic told me that cars that sit have more

problems. I suggest you spend more time driving your car once it is repaired.

Paul

That statement is not true. Only cars that sit for very long periods of time where the seals dry up, moisture gets into the car, and/or they get attacked by rodents have "sitting" problems.

My RMS leaks about 2 drops per week in the summer and stops in the winter as the seal expands with the temperature. Certainly not worth the trouble to replace IMHO.

This statement was made by a Porsche mechanic. It was his observation that

cars that sit around tend to need fixing.

This is not my statement.

Paul

Then I guess my point is why repeat something here that you do not know to be true. IMHO it just leads to more myths and unsubstantiated rumors about these cars.

  • Upvote 1
Link to comment
Share on other sites

Don’t mean to steal this thread, but I have a question to JFP.

You mention use of 10W40 oil in 996/997 engines. I don’t mean to start another oil thread. Believe me, I read many of them and after much reading I came to conclusion that for spring-fall driven 996/997 the 10W40 makes most sense. Would you mind expanding on this subject a bit as you seem to speak from experience.

Many thanks,

Luxter

Link to comment
Share on other sites

  • Moderators

First, and perhaps most importantly, let's please not turn this into a "Brand X vs. Brand Y" endless argument, and not divert the thread even further……..

Based upon UoA's collected over many years, conversations with a few the leading Porsche aftermarket engineering development firms, and a few of the leading Porsche M96/97engine builders; we came to the conclusion that sole reason for "recommending/approving" 0W-anything oils has more to do with CAFÉ mileage ratings than protecting the rotating assemblies' in these engines. Porsche is not the only ones to move in this direction, and in several cases (BMW and Toyota, for example) companies have ended up regretting it and moving back to heavier "W" weight oils when warranty engine replacements became excessively high, or the associated public relations became too negative. Oils with very thin "W" weights simply do not hold up to high shear or high temperature very well or for very long, and need to be changed more frequently rather than at the OEM recommended intervals. UoA's have shown that one of the most advertised brands of "full synthetic" 0W-40 was sheared down to the point It no longer could remotely be considered a "0W-40" product (technically known as “having fallen out of grade”) in only a couple thousand miles in something as mundane as a Cadillac.

Combine that with the fact that not that long ago, 10W oils were often the recommended weights for use in very cold (near arctic) climates, the rational for using such thin oils in more temperate environs becomes even more suspect. So we began testing several different brands and weights of oils, including some very hard to obtain and/or expensive products, eventually settling on a readily available full synthetic 10W-40 product for use in these engines. Ongoing UoA's, combined with the occasional tear down, have shown that the weight combination works very well from an engine preservation standpoint. For extreme climatic conditions (truly arctic), we have also found that a 5W-40 synthetic also works very well, but requires more frequent changes as it will begin to shear down more quickly than its 10W-40 cousin.

And before someone comments on the ability of 10W-40 weight oil to circulate on cold start; at 6:30AM this morning, the air temperature was 3F outside my home. My personal car, which sat outside last night with 10W-40 synthetic in it, turned right over and had nearly full oil pressure when the engine fired. You need to ask yourself, how thin does it really need to be?

Edited by JFP in PA
Link to comment
Share on other sites

Once the transmission and engine have been separated to replace the RMS will a failing IMS be obvious? I take it in Weds and would like to know what is the process for checking the IMS. I can imagine that when the IMS completely goes that it is obvious. I'm looking more for a litmus test that says it is "about to go" or has good odds that it "will go". Thoughts appreciated.

Link to comment
Share on other sites

  • Moderators

Once the transmission and engine have been separated to replace the RMS will a failing IMS be obvious? I take it in Weds and would like to know what is the process for checking the IMS. I can imagine that when the IMS completely goes that it is obvious. I'm looking more for a litmus test that says it is "about to go" or has good odds that it "will go". Thoughts appreciated.

Usually, there is really nothing physical to see. When the IMS starts to go south, the fastest way to catch it is to look at the VarioCam readings on a PIWIS or Durametric system, which will see the wobble in the bearing as swings in the cam "allocation". Unfortunately, all too often, there is no prior "announcement", and the unit catastrophically fails, taking the engine with it.

Major point is that you would be replacing the OEM bearing, hopefully before it even starts to fail, with the LN Engineering replacement unit which uses much better components.

Edited by JFP in PA
Link to comment
Share on other sites

JFP,

In addition to coleta's question....Will the technician know what the tolerance or allowable 'wobble' allowed between the cams? Do you measure the variance at accel then again at decel? I'm not planning to crack the engine open at my cost. If Porsche is covering the RMS I'm thinking they might cover IMS but it would need to be defendable. When Porsche fixes IMS issues do they replace the case? In my situation I suspect I don't have an obvious failure if any at all so a bearing going bad might be difficult to prove. To replace the bearing with the LN version as a preventative measure might be costly and risk other problems later.

Link to comment
Share on other sites

  • Moderators

JFP,

Which variocam readings are you refering to, the actual angle or the deviation?

Thanks

Both. Just be aware that strange or unexpected readings can be an indication of an IMS coming unglued, but they can also result from other issues as well, such as the VarioCam unit itself going south, very bad tensioners, or severely worn chain guide paddles. If I saw strange values, I would pull the oil and filter, looking for granular ferrous metal, a sure sign of looming failure. If I found nothing in the oil, I’d start looking at the other potential candidates.

One of the most insidious factors with the IMS is that it very often gives no warning of any kind.

Link to comment
Share on other sites

  • Moderators

JFP,

In addition to coleta's question....Will the technician know what the tolerance or allowable 'wobble' allowed between the cams? Do you measure the variance at accel then again at decel? I'm not planning to crack the engine open at my cost. If Porsche is covering the RMS I'm thinking they might cover IMS but it would need to be defendable. When Porsche fixes IMS issues do they replace the case? In my situation I suspect I don't have an obvious failure if any at all so a bearing going bad might be difficult to prove. To replace the bearing with the LN version as a preventative measure might be costly and risk other problems later.

I'd doubt that they have any experience with reading the cams and learning anything from it. Yes, we would look at both RPM rise and fall as the cams tend to get pretty erratic as the engine transitions, indicating that something that shouldn't be is moving. But, as I mentioned to another poster, this can also result from other issues as well, so further investigation is required if you encounter it. You should also be aware that by the time the engine gets to this state, it is literally "on the edge" of failure, and can go at any time.

I also doubt that the dealer is going to do anything with the IMS unless there is significant metal in the oil and filter. While it may sound like heresy, the dealer's tech's are simply not trained and/or equipped to work on the internal assembly of this engine; so they just replace the entire engine when they encounter a bad IMS. From their perspective, it just makes more economic sense to pull the engine and replace it (at last count, a full set of just the special tools required to scratch assemble one of these engines was over $10,000, and these tools have no other use. Just the OEM tool to replace your RMS with the latest version is $464 alone.). As this has been dealer practice since the M96/97 was introduced, I would doubt that very few, if any, of their staff could even do it if they wanted to, and also explains why quality aftermarket engine builders are expensive.

Lastly, and again sounding somewhat like a heretic, a lot of dealers are still in denial about IMS failures. After multiple magazine articles on the subject, many dealers still claim that the bearing cannot be changed on the pre '06 engines without splitting the cases, which is anything but true. While there are some dealers that are actually installing LN upgrade kits, many are not, and stick to trying to sell new engines..............

Edited by JFP in PA
Link to comment
Share on other sites

JFP, I was under the impression that the deviation values was calculated at cranking and was not "live" data. So if the IMS went, the only way to see a change would be to note the deviation, turn the car off and then on again and recheck to see if it changed.

Is this right? If it's not, have you ever seen deviation values change while the car is running?

Thanks again.

Link to comment
Share on other sites

  • Moderators

JFP, I was under the impression that the deviation values was calculated at cranking and was not "live" data. So if the IMS went, the only way to see a change would be to note the deviation, turn the car off and then on again and recheck to see if it changed.

Is this right? If it's not, have you ever seen deviation values change while the car is running?

Thanks again.

Both the Durametric (Pro) and the PIWIS can see the cam deviation values live (engine running). You can see the cam positions (in degrees) at idle and at RPM, which is a diagnostic for checking how well (or if) the VarioCam is working.

Edited by JFP in PA
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.