[ace1eleven]

After purchasing my 335is I read quite a bit about the HPFP failures and subsequent warranty covered replacement being common on the N54s. Since this was a newer version of the same engine I hoped that BMW would have taken the time to fit these "HP" versions with the re-engineered pumps. Apparently I was wrong about that as I had to have mine replaced yesterday.

The symptoms of the failing unit were so similar to a clutch wear or malfunction in the DTC that this car is equipped with that I thought there was a serious issue and I brought my car in twice to get some diagnostics run (among other services). The car acted like the clutch was no longer engaging/disengaging in a linear fashion and I was getting nervous about the longevity of the DCT unit. Happily, I found today that the HPFP was the culprit. After getting the newer better HPFP my car runs and shifts butter smooth. This is great as now I don't have a lack of confidence in the quality and reliability of the DCT in the still relatively new 335is, but I did want to put this out there in case anyone else is experiencing the same behavior with their car and are going down an unnecessary path of troubleshooting when all they need to do is get a new HPFP fitted.

What you will see if it has failed or is failing is an "Engine Malfunction, Power Reduced" warning on the display. This allows you to drive the car in a limp mode, but in my car at least, I didn't notice as difference (only drove a mile or so and didn't test the limits of RPM, speed or power), but I chose to have it towed to BMW anyway. Your choice on whether or not you want to drive it in or have a flatbed come grab it. If you are seeing these symptoms and do not yet have the warning, call Suzanne at BMW Seattle and mention what I have described and she will know what you're talking about. Not sure if this can be replaced via warranty or recall without it actually having a failure, but it would be well worth the effort. You don’t want to get stuck in limp mode while on a spirited drive on 101 like I almost did.

Anyway, I will post another thread for this with a title that reflects what seems like it could be a problem with the DCT or the associated clutch and hopefully it will save someone time and headaches.

[jdhart]

Originally Posted by ace1eleven

The car acted like the clutch was no longer engaging/disengaging in a linear fashion and I was getting nervous about the longevity of the DCT unit. Happily, I found today that the HPFP was the culprit.

I'm curious if you could elaborate a little bit on this portion. My car has recently been "jerky" from take-off occasionally and I'm out of warranty so was thinking about having an indy check the trans and engine software to see if they are up to date.

[ace1eleven]

Originally Posted by jdhart

I'm curious if you could elaborate a little bit on this portion. My car has recently been "jerky" from take-off occasionally and I'm out of warranty so was thinking about having an indy check the trans and engine software to see if they are up to date.

Basically similar behavior. Jerkiness from a stop, in lower gears and more pronounced when cold and/or when in manual mode. Assuming that since yours is out of warranty you have a 335i with an auto keep in mind that I am talking about the behavior of the DCT trans.

I also had a recall applied on another service visit that addressed "shift quality" that made the shifts when not in sport mode a little snappier.

[jdhart]

Originally Posted by ace1eleven

I also had a recall applied on another service visit that addressed "shift quality" that made the shifts when not in sport mode a little snappier.

Do you know if this was just a transmission software update?

[ace1eleven]

Originally Posted by jdhart

Do you know if this was just a transmission software update?

I am not positive if it only effected the programming for the trans, but it took them several hours to complete the work so I would assume it was more than just a shift mapping update.