jacdx

Hey guys,

Over the last couple months, I've noticed that my 05 545i has started to be rough when holding moderate speed, meaning not accelerating, not decelerating, just holding speed, say 45mph in 4th gear.

It noticeably jerks. It goes away as soon as I let off on the gas or if I accelerate. It does it in more than one gear.

I took it in for service for a bunch of little things I've been putting off and they wanted me to do a "top engine clean" for $140, saying it was carbon build-up. Does this make sense to anyone. To me it seems like any drive quality issues should be covered under the warranty...but apparently if they can pin it on some fuel issue they have an out.

Thanks,

--jacdx

smarty156

Try cleaning the air filter as well.

545OH

Use seafoam in your gas tank and engine-works wonders. Seafoam.com. Decades of people swearing by this stuff, muyself included

miguex

I went to http://www.seafoam.com/ it shows a nice Motel website... lol

Anyways the website is http://www.seafoamsales.com/

Will Greer

This happens in mine as well. It never happens if I am in DS mode, though. I strongly suspect that the problem is in the transmission programming (and not a mechanical fault). The transmission seems to be initiating, but not fully executing, a shift from 5th to 6th gear. DS doesn't use 6th, so the problem does not occur.

I may or may not experience the problem less immediately after I do the "hold your foot on the gas pedal for 60 seconds" transmission programming reset trick. In any case, I suspect it is not harmful, just another little nit about these ZF transmissions.

FWIW, when I complained about it to my dealer, they claimed I had carbon buildup and charged me $180 for a cleaning. The problem occurred on my way home from the dealer that same day.

vlad_b

thanks for sharing, i suspect Software problem too. I have a 05 545 and have reprogramming scheduled for tomorrow.. will see how it goes. so far i changed sparplugs - didn't help much. Airfilter is another guess - will do it too..

btw. i noticed a lot of 545 owners complaint about rough idle and transmission slam.. hope we will find a definate cause of it soon. Dealer said "that's the wau they are, v8 on bmw are rough" but i don't believe them. someone mentioned here that it could be valve lifter's - and i hope it's not the cause

MacoBMW4life

i have the same problem in my car...i do the tranny reset once in a while and it seems to shift smoother and the jerking goes away for a while.
I think someone here once said it's the "mechatronics" or something like that...let us know what the dealership says, and which dealership are u going?

jacdx

I'm going to try some Seafoam. I doubt this is a software problem as it is a recently development (over the last 1000 miles since 30K or so). It has been silky smooth up until the last couple of months.

Any good places to get it locally, off-hand?

Thanks,

-j

jacdx

I should mention that this is a 6MT.

ADD

Save your money... for now.

Run the tank down to 1/4 and throw in two bottles of Heet DryGas, and fill up.

I just put a bottle in today before a fill up.

I have had very similar problems, and the dry gas cured everything.

I am seriously thinking that US gas producers are either a) screwing with the gas, b) adding more ethanol than is necessary to trim expenses, or c) my 535 is much more sensitive to these changes.

Never had a problem with my e39, but I have a standing order for the Heet DryGas since the weather turned colder last year.

HTH