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.