Pls help: RMS vs IMS failure?
 

Have a 2004 tiptronic Boxster S. 3 years ago (20k miles) engine was replaced due to a "sheared bolt". Now I just towed my car (30k miles) with the same symptoms to the garage and fear it is the same thing. Symptoms = thrashing noise (like tree branches wrapped around the axle) and all the oil just poured out the car like a spigot. What are the RMS and IMS failures and which am I likely to have? Any tips on getting Porsche to replace the engine AGAIN (it's not under warranty now). I don't trust the dealer garage; it's with another mechanic for diagnosis now. Love my car, but this is too much!

This does sound like the IMs failure to me.. Generaly an RMS failure will create no mechanical sounds..
I have experienced several clients that have had multiple failures, one of them is on engine #4 at the present.

It has become clear that driving style impacts the IMS failure.

The engine could be salvageable so get a second opinion from someone with the proper internal comprehension of the M96.

I can suggest shops in So. CA where is your car? :confused:

Thanks for your responses, guys.
Jake--not sure what you mean by driving style b/c the car is barely driven--usually ~15 miles to work, 70ish mph on the highway, or an occasional outing on the Pacific Coast Highway. Hardly anything I would call aggressive. I would hope Porsche can design a car for normal driving...but I'm beginning to doubt this.
BY-I'm in Thousand Oaks, Ventura County. Recommendations would be much appreciated!
S

If I'm reading Jake correctly, he's saying failures, especially multiple, may be caused by driving style. Short trips, occasional & mild usage, lugging the engine, etc. , are bad for the M96 engine, so it would be better if you did drive aggressively (after the car is warmed up).

Didn't your replacement engine come with a 2 year warranty?

Like I said, it seems that certain driving styles lead to more frequent occurrences of the IMS failure.

If I explained that in detail a flame war would probably follow...

What he is saying is........(if I am reading between the lines a bit) once the car is warmed up, Drive it like a Porsche should be driven not like you would drive your Grandmother's Buick. I remember a LONG time ago talking to a Porsche mechanic and he stated that one of the reasons that we have problems with our cars (911's at the time) is because they are not driven like they should be. They need to be driven hard after they have properly warmed up.

Due your car a favor. Romp on her today!!

Just no tickets please..

Thanks.

I will also state that very rarely do we get calls from owners that have experienced the IMS failure who had previously owned and driven an Aircooled Porsche...

being not old enough to really have owned or experienced an air cooled porsche (I do love the 993 but but I was only 10 or so at the time.)

im not sure I understand the implication here. is it a style of driving or is it an understanding of how porsches work or what it is. :confused:

Please correct me if I am wrong, but the history surrounding Porsche is of Race heritage. Porsche's were designed to see tracks or high speed highways on a regular basis. Many times, around town driving, or anemic driving does not allow the fluids to heat up to proper temperatures, thus causing damage to internal parts of the motor. When a vehicle sees tracks, higher speeds or harder loads it will burn off these impurities, thus causing less wear and tear on your parts. These vehicles will also see more fluid changes than cars that are parked in a garage and allowed to sit there looking pretty. That is why many Porsche owners will autocross or track their cars on a semi regular occurrences. The vehicles that are garage queens have a tendency to have more problems than the vehicles that are regularly driven.

tnoice. not sure if you were addressing my post but ill supose you are. I understand that completely it was just the relation between the aircooled owners and those not. It isnt that i feel offended or defensive or anything of the sort just interested in knowing the correlation.


I figure if my IMS is gunna go then so be it. but hey if jake says more RPMs a day keeps the doctor away then hell... ill take a double dose of that medicine!

This is great news! I don't need to worry about my car's IMS anymore!!

I am in O.C. & don't know much north of LA but I can recommend Callas Rennsport in Torrance. 310-370-7038 It is worth your time to give them a call. Get the June issue of Excellance magagine & read the Tech Forum on page 129 about IMS failures written by Tony Callas @ Callas Rennsport he my be helpful in warranty advice for your engine. EBS racing@aol.com had a good price on a new engine$10,000 & good to deal with if you go that route. I do not recommend any of the local engines advertised as rebuilt. I would definetly contact the dealer that installed the engine to see what they will do for you.

No engine should be started unless it will be allowed to reach its operating temperature (minimum 180 degrees) Porsches seem to need the higher oil pressures that come at higher RPMs (3500 + ) for best lubrication in the engine, IMS included. And specifically in the case of the OP Vario-Cam engines should not cruise @ 2200rpm - 2500rpm to prevent Vario-Cam advancing back & forth or off & on.

While generally true, remember that the IMS bearing does NOT receive pressure lubrication, but is a sealed bearing (and that is a good part of the problem). Also, since his car is an 04, it has the newer, vane cell type variocam, that does not change the chain tension as it works.

Is it a style of driving or is it an understanding of how porsches work?

Throw a brick on the accelerator and left foot brake :D

Just kidding, of course. Being a 911 guy, we like to drive our cars in the upper revs...power is there and it builds the oil pressure. Lugging a Box engine around town or on the highway is bad news...I rarely use sixth gear because US highways just don't allow the speeds that come with driving in the proper RPM range; i.e. >3200 RPMs.

I know you don't like to cause controversy, but I'd like to hear more of what you mean. And I understand no little ol' lady driving.

I make regular trips to 7k, but make no to effort to keep rpm up constantly. The old pre-CD ignition cars required revs to keep the plugs from fouling.

My signature says it all. I have been driving Porsches hard since 1974 and they have been very trouble free. Just yesterday I participated in a 300 mile tour where I floored my 01 at almost every start and shifted at 7000 rpms all day long. BTW so were all the other Porsches.....(30 or so).

For what it is worth I got this explanation from a respected Porsche mechanic.
The factory Bering has a plastic seal that locks in the factory grease.
The plastic seal is crappy and engine oil seeps in and washes out the factory grease.
Low engine revs, low internal pressure, long oil change cycles allows the old poor quality motor oil to stay inside the Bering rather than a pressure forced change.
As a matterof fact if you can not afford the IMS retrofit/repair, I was told to fully remove the factory crappy plastic seal entirely so that clean motor oil can bathe the berings at the very least.

Just passing along what I was told.

Again, the IMS bearing (by the way, it's "bearing," not "Bering" as we're not talking about the Bering Straight here, thus no capitalization is needed) is NOT pressure lubricated. You're absolutely correct in that the "sealed" bearing is not really sealed and that the sealed lubricant gets washed away by the thin motor oil, which is nowhere near as good a lubricant for a ball bearing. Removing the seal on the factory bearing will allow engine oil to at least get in there and provide better lubrication, but under no circumstances, regardless of RPM, is there pressure lubrication to the IMS bearing.

I understand that the bearing is not pressure lubricated by design. That's my point. The internal pressure forces past the plastic seal by accident and washes out the factory grease. The point of the post was to explain how high revs and high pressure can be good in that it changes more oil inside the bearing.



And by the way I am not an idiot. I was typing on my Iphone and it auto inserts words. I sure you understood I did not mean the Bearing strait, but thanks for pointing that out.

I generally don't post information that I can't back up with empirical data, because some jackass is bound to challenge me and I like to be prepared for that.

Lets just say the phone calls I get don't come from people that admit to driving their car hard..

Just to better understand this issue...
Jake,

The oil that comes out from a RMS leak, is the oil going around the bearing or through it?
Along those lines...If it is going through it, do cars like mine that had 4 RMS repairs prior to the IMS replacement have a less chance of failure?
Should a very leaky RMS be replaced?
Do cars that have a single leak and then never leak again have a greater failure rate because there is oil going through the bearing, but at a slow rate and therefore not washing completly through?

Enquiring minds want to know

When the outer seal begins to be compromised engine oil is allowed into the bearing. This oil washes the permanent lubrication from the sealed bearing. As time goes on the oil will seep through the inner seal and into the IMS tube little by little.

Fast forward a few thousand miles and the inner seal becomes further compromised, along with the outer seal, the release of oil that has accumulated inside the tube is what ends up on the garage floor as it bypasses the OE bearing flange in the center. This oil is nasty black because it has been caught up inside the IMS tube through many heat cycles.

An RMS and IMS leak is much different and not related.

Yes. It also must be absolutely proven that the leak is from the RMS, not the IMS as the symptoms are virtually the same. If it is from the IMS then the bearing must be changed ASAP since the release of oil is the first sign that the IMS is beginning to go.

?
Perhaps, but I still think you may have the IMS and RMS confused.

My apologies.

However, you must separate the RMS and the IMS. The RMS is simply a seal that keeps oil from leaking out of the junction of the case halves and the back of the crank, where the flywheel attaches. It is completely separate from the IMS, which is below the crank. Again, high revs and higher oil pressure have nothing to do with IMS lubrication, as the only oil that gets to that bearing is from windage and splashing. There is NO pressure feed to that bearing.

On a related note, the oil that does get to the IMS bearing does not go around or bypass the RMS (as again, they are completely separate), so you could replace the RMS seal 25 times, and this has zero impact on the health of the IMS bearing below it.

I understand the difference, I just dont know in which direction does the oil flow.

hang with me for a second:

If it works like this: the oil from the motor, goes through the bearing, and then to the rear seal, then to the garage floor... more oil on ther floor would be good in that the old motor oil is not blocked from "passing through" and does not back up inside the bearing.

OR

the oil goes to the real seal area, and then pools, then seeps into the bearing, and into the tube, and back out the tube pass the bearing. In that case the rear seal leak would have not much to do with failure.

OR

Am I wrong in both areas?


Also why does porsche not just recall the cars and fix the issues and thier reputation by doing the retrofit as a recall.

Yes. Two completely separate things.

Now, as to why Porsche doesn't do what Mazda did with the RX8 motors (where they gave the early cars, which had a higher chance of blowing up, a complementary 100k mile warranty) or something similar is beyond me, though I understand their mindset unfortunately. You would think that the company would be concerned with bad PR and pissed off owners who will never buy the marque again, but it's not quite that simple.

All companies know their buyer demographics, and who buys their products new, and second-hand. As such, Porsche knows (and I'd say at better than 95% correctly) that the people who buy used Boxsters will never buy a new Porsche, so really, despite how pissed off you are that your car blew up and that you'll never buy a Porsche again, they haven't lost a sale, as you weren't going to buy a new car anyway (aside from selling parts, they could care less who buys the cars used). Sad but true.

This also explains why there are many documented cases of original owners getting goodwill replacement motors (after the warranty expired). That's because this guy DID buy the car new, and likely will again, so they don't want to piss him off by saying "sorry, out of warranty, but here's your $15k bill to fix your car."

Oil doesn't flow to either, it is delivered via splash.

hang with me for a second:

Which bearing??

No... You are associating the seals.. They are not associated at all. Two different components..

OR

Nope... The oil that gets into the IMS isn't coming from the RMS.

That would be admission that a problem actually exists..

Deny, Deny, Deny...

This picture may help you. This is the view from the rear of the 1-3 case half, during assembly with the bearing carrier (which holds the crank) inserted. To the left is the rear of the Intermediate Shaft (where you can see the end of the bearing behind the flange), and to the right is the back of the crank. The gap between the crank and the case half is where the RMS seal goes.

As you can see, the RMS and the IMS are completely separate, and do not share oil in any way.

OH!!!!!!!!!!!!!!!!!

Got it it now. I thought that the Rear main seal was in front of the IMS. I did not realize that they where in two different spots. Thank you. I had the RMS replaced four times and the oil looked like it was coming from the IMS area, I guess it was pooling in the bell housing.

I love reading this statement. The more excuses I have to drive the hell out of this 2.7, the better. I haven't hit the rev limiter yet, but I have been about 200 rpms into the red. Unfortunately any red in 3rd gear is way over any posted speed limits.

rms
 

i have a 97 boxster 2.5 just had it serviceds and it needs the rms doing as it is leaking at 50k miles i have only had the car for 3 months done 2k miles in it plan to drive it as my day to day car once the rms is replaced will this happen agian the car has a full service history and has had the rms done before.

what is the chance of ims happening at 50k miles +

also the drive window sticks some times when openning/shutting the door garage wants to replace the door lock £125 but isnt there a senser they could check first?

love the car but this rms and ims is a bit scary

as for the window, pull the panel and shoot some spray white litium grease on gears and rails. Sometimes the soundproofing gets pulled into the rails or gears also.

For the RMS- mine has been fixed three times. finally it is holding. The RMS just leaks oil and makes a mess. unless it is pouring out or you are doing a clutch anyway, fixing it is not really needed.

As for the IMS- it can go without warning at any time regardless if the RMS is leaking or not. If the RMS or clutch is going to be fixed, it is simplely a matter of 600$ to have the IMS replaced.

The cost of the IMS replacement is in the labor to get there to begin with.

40-60K has been the "sweet spot" for several IMS failures......

IMS replacement
 

OK can some please tell me that if i get the IMS replacement for my 01 Boxster will that in fact take care of the failure of IMS or am i still in the same place. porsche service has not been very helpful !!
thanks
FTOR

Jake Raby and Charles Navarro have been "suggesting" replcement of the IMS at normal clutch replacement intervals (40-50K miles), just to be safe until a larger base of installed units can provide better data. Last I heard, to date, no replacement LN IMS unit has failed in service................

I would like to know what happened to the original car that began this thread. It is too bad that many times, someone pops on to state an issue and then no follow up. :(

Thank you, i purchased the car with 60K miles, i have the 60K service comleted and the shop said overall very good car. i do trust the shop since they have worked on my benz for years. is there a way i can check the IMS to see if it may have been changed or is this require a major disassembly. i would hate to spend 1k if the IMS has already been done?
help if you can
thanks

Unfortunately, the only way to inspect the IMS is to pull the gear box, and then remove the clutch and flywheel. Many Porsche dealers still are telling people that the only way to change the IMS bearing is to split the cases (total disassembly of the engine), even though not just independent shops, but backyarders are pulling them from fully assembled engines and replacing them with the LN unit.

Two things to consider: If the IMS bearing had be upgraded, it would have been a featured selling point when the car was sold; dealerships (in general, as LN has won some converts) would not change the IMS bearing, they would replace the engine.

You can also check with LN Engineering to see if you VIN is listed as having been upgraded…………

Unfortunately, probably like many other that have had one of these failures, the poster is no longer “part of the family”. More than one individual that has lost an M96 to the IMS while still under warranty immediately traded in/sold the car as soon as they got it back. One guy lost two engines this way, and drove the car with the second warranty replacement directly to another brand dealer the same day and traded it in….. And you can’t really blame them.