Engine trouble - "Tach Jump" causing power loss - ANY IDEAS?

[jeremyc74]

Originally Posted by Night1

Update: BMW is currently doing a smoke test on my car to check for possible leaks in the vacuum tubes. They admitted today that they have no idea what is wrong with my car. Even 2 BMW field engineers have been sent to inspect it in person, and they are clueless.

If this sh*t continues much longer, I will be looking for a new car.

At this point I'm wondering if our internet diagnosis is accurate, based on the information. There's got to be something else in play here. There's no way this many experienced people have failed to diagnose a slipping clutch. I was able to do that by the time I was 16 years old, and I'm certain a BMW field engineer could do it. :iono:

[123D-M]

Originally Posted by jeremyc74

At this point I'm wondering if our internet diagnosis is accurate, based on the information. There's got to be something else in play here. There's no way this many experienced people have failed to diagnose a slipping clutch. I was able to do that by the time I was 16 years old, and I'm certain a BMW field engineer could do it. :iono:

If it's like mine it's an intermittently slipping clutch which is more difficult to diagnose. I swapped cars with the customer service manager for a night so he would hopefully experience the problem and of course it didn't do it.

[Justabanana]

How has no-one yet asked for this clarification:

Does only the tachometer jump, or do you also hear the engine revving up?

a) If the heard engine speed matches the tacho, then it has to be a powerline-issue (the clutch).

b) If the heard engine speed does not match the tacho movement, then the problem is elsewhere. Maybe in the electronics?

Let's hope for an answer a), since that'd be much simpler to diagnose. So simple - as someone already said - that any mechanic should figure it out immediately. These ecu-upgrades make me fear we have a case b) here...

[123D-M]

In my case there is no need for clarification. The clutch is slipping. Period. It's already been replaced once and they found evidence of oil leaking in there. Hence the slipping.

And the OP's symptoms sound just like mine.

[jeremyc74]

Originally Posted by Justabanana

How has no-one yet asked for this clarification:

Does only the tachometer jump, or do you also hear the engine revving up?

a) If the heard engine speed matches the tacho, then it has to be a powerline-issue (the clutch).

b) If the heard engine speed does not match the tacho movement, then the problem is elsewhere. Maybe in the electronics?

Let's hope for an answer a), since that'd be much simpler to diagnose. So simple - as someone already said - that any mechanic should figure it out immediately. These ecu-upgrades make me fear we have a case b) here...

It was asked earlier in the thread, and the OP said the engine is indeed revving up as the tach moves. Given that information (and assuming it's correct) the answer is so obvious I can't believe they haven't gotten to the root of the problem after this amount of time. :iono:

Of course, my service department has proven incapable of even properly performing a routine service, so at this point I guess I wouldn't be surprised to find out that they can't figure out a slipping clutch.

[Night1]

Originally Posted by anthony@rissracing

They will figure it out I'm sure. Do you have the service records of what they have checked. If so give me a call tomorrow I'll see if I can have our techs help nail down the problem...

If they will give me a record of what they checked I will send it to you. As for now, I can barely get updates on my car. Thanks for the help!

Originally Posted by jeremyc74

At this point I'm wondering if our internet diagnosis is accurate, based on the information. There's got to be something else in play here. There's no way this many experienced people have failed to diagnose a slipping clutch. I was able to do that by the time I was 16 years old, and I'm certain a BMW field engineer could do it. :iono:

At this point I'm as stumped as the BMW engineers.

Originally Posted by 123D-M

If it's like mine it's an intermittently slipping clutch which is more difficult to diagnose. I swapped cars with the customer service manager for a night so he would hopefully experience the problem and of course it didn't do it.

This makes the most sense to me, and so far your car's problem is the closest I can find to mine. BMW head tech (and apparently the engineers now) currently doesn't think it's the clutch.

Originally Posted by jeremyc74

It was asked earlier in the thread, and the OP said the engine is indeed revving up as the tach moves. Given that information (and assuming it's correct) the answer is so obvious I can't believe they haven't gotten to the root of the problem after this amount of time. :iono:

Of course, my service department has proven incapable of even properly performing a routine service, so at this point I guess I wouldn't be surprised to find out that they can't figure out a slipping clutch.

You're correct, as stated before, the engine revs along with the tach.

[imdanomite]

they would definately know if it were a clutch. don't underestimate a BMW tech/field engineer/PuMA

[jeremyc74]

Originally Posted by imdanomite

they would definately know if it were a clutch. don't underestimate a BMW tech/field engineer/PuMA

If the symptoms are being described correctly (and they seem to be) there's NOTHING it could be but the clutch.

[SV Concepts II]

Maybe the clutches in these cars are clutch-by-wire?

The techs will eventually figure it out. Hopefully soon...

[jeremyc74]

Originally Posted by Ali@Jlevi SW

Maybe the clutches in these cars are clutch-by-wire?

The techs will eventually figure it out. Hopefully soon...

It's beginning to look like they're also self lubricating. :biggrin:

[JB135i]

Originally Posted by jeremyc74

It's beginning to look like they're also self lubricating. :biggrin:

Did you mean the clutches were self lubricating or the TECHS? LOL

The reason I ask is most the people I have met at dealerships are indeed raging $$$K-offs.

[ML]

Originally Posted by Ali@Jlevi SW

Maybe the clutches in these cars are clutch-by-wire?

I guess that makes all those modified CDV's a complete scam... LOL

[Night1]

Update:

This isn't much of an update but I called them again today and they told me they are "currently swapping out parts between my car and another on the lot, and testing to see how that affects the problem."

They still don't have any answers.......

I've asked them to send me a list detailing everything that they have done to my car along with what they've tried, etc. If they ever send me that list (I doubt they will), I will post it.

[jeremyc74]

Originally Posted by JB135i

Did you mean the clutches were self lubricating or the TECHS? LOL

The reason I ask is most the people I have met at dealerships are indeed raging $$$K-offs.

Could go either way I guess.

[ML]

Maybe you shod suggest that, rather than swapping parts with another car on the lot, they should just give you another car and, if it happens again, then they can have both cars back.

[Riss Racing]

Originally Posted by Night1

Update:

This isn't much of an update but I called them again today and they told me they are "currently swapping out parts between my car and another on the lot, and testing to see how that affects the problem."

They still don't have any answers.......

I've asked them to send me a list detailing everything that they have done to my car along with what they've tried, etc. If they ever send me that list (I doubt they will), I will post it.

If your not getting the level of service you feel you deserve. Contact BMWNA. After you do that you will see the service get a little better :thumbup:

[gnpower]

I heard and seen guys go through a clutch within 5k miles. Some take 100K miles. It all depends on how you use/abuse it. We don't know how hard this car has been driven in the past 14k miles. So a slipping clutch could be a possibility. The question is will BMW fix even after they know you had an aftermarket intake installed. They'll find anyway out of repairing a vehicle

[Night1]

Originally Posted by anthony@rissracing

If your not getting the level of service you feel you deserve. Contact BMWNA. After you do that you will see the service get a little better :thumbup:

UPDATE:

I have about 1 minute to quickly type this but here goes. BMW's field engineers say the clutch is fine. They are currently believe it to be a wiring or programming issue. Next on the list to be checked is the DME (main computer).

In the meantime, I have followed the recommendation and contacted BMWNA. I've explained my situation to them and am awaiting their response. They were extremely helpful.
My car has been in the shop since 12/17/08! :eyebulge:

[Robert]

Sorry to hear that. Your car and mine were built around the same time period and I had an SRS sensor in the roof went out on me and caused some electronic havoc.

[Night1]

Originally Posted by robert

Sorry to hear that. Your car and mine were built around the same time period and I had an SRS sensor in the roof went out on me and caused some electronic havoc.

Yeah, that sucks. Hopefully they got you fixed up.

[Night1]

UPDATE:

I still haven't driven my car since it's been in the shop but according to the techs, the software update changed the tach/engine problem. Instead of the tach jumping up (and then back down) when you begin acceleration, the tach now lowers for a second (and then comes back up) when you accelerate. Either way, the engine hesitation is still there. The techs and the 2 field service engineers do not believe this is related to the clutch. They are currently working on the wiring or main computer.

One thing that is confusing the whole issue is that there are so many people involved in the diagnosis that I get updates from a different person each time. They have still failed to provide me with any sort of paperwork stating exactly what has been done to the car, what stock parts have been swapped out with other stock 135i's on the lot, etc.

I'm sure I will have some interesting updates soon.....

[imdanomite]

hey, atleast it's a progression. like i said before, it's some sort of programming issue. i have yet to see a clutch go bad. E9x had a rear main seal issue a while back, but even then, that didn't cause a clutch to slip.