Z4-forum.com

Hi all

Driving the sDrive35iDCT yesterday , ready to overtake an elderly gentleman doing 20mph on a national speed limit road, check mirror, all clear , indicate , foot down , nought coming out .. delayed response in acceleration and a lacklustre pause before the power came through, which never seemed as near the power I have become accustomed to.

Is this the"turbo lag / fuel pump issue previously discussed here?

Any Advice

What sort of revs?

No probs with mine although it is a manual.

Any strange noises from the engine (the turbo fault)? If it's the fuel pump you will get a warning light and reduced power warning coming up. I had this the day after I had mine!

They say that Z4's should not suffer the turbo problems as this was on engines around 2007/08.

Quote from the report:

BMW spokesman Matthew Russell says that:

The turbo complaint is much less widespread and we have had a service bulletin in place since 2007 to address it. In an effort to address specific noise concerns, BMW updated the turbocharged engine software on 335i/xi and 535i/xi models built from June 2006 through March 2008. The updated software causes a small amount of increased "turbocharger lag" under certain circumstances and, while not substantial, the lag may be perceptible to the most sensitive BMW drivers. X6, 135i, and 3 Series/5 Series vehicles from March 2008 production onward are not affected."

Hi Breaker, revs were I would estimates at 2,500 when I went to overtake and put the pedal to da metal & things just went flat for a while, then the revs raised but much slower than usual, so further up the road I pulled over, switched off, restarted and hasn't happened since. Could it be dodgy fuel? (only use Super) or just a blip??

ref strange noises, none that I can hear but I've only had it three weeks and its hard to tell with the idrive screen going up and down, up and down etc

should I be watching incase it's the fuel pump? what happened when yours went break?

regards

IwatchLive

Isn't around that RPM where there is a small bit of lag in the power curve? I never overtake from that low in my manual car.

When mine went it went into half power (came up on the sta nav screen) and a warning light came on. This was around 70 miles from home! I phoned BMW from the car and they said it's OK to drive home but take it to dealers as soon as I can. Got home OK but just felt like someone had put the 2ltr engine in!

Took it to dealers the next day. They looked at it and ordered parts. Never really said what was wrong but they re-set the computer to enable full power again. I didn't drive it much after until it was fixed. Never had a problem since and have now done around 17,500 miles.

Feel a wee bit silly because I would not know what to be listening for specifically, but I did yesterday get a couple of strange loud pops from the rear end when holding revs just under turbo level ready to let her ripo, then had this laggy experience a bit later on.

doesn't sound like your issue though pal

Could be something to do with fuel as you said if there were pops from the exhaust. Just keep an eye on it and try not to worry. BMW are aware of these problems and they do fix them if it is one of the known ones.

Also, how many miles has yours done? Mine is getting better engine wise the more miles I put on it!

Hey
only done 9K, also gets better looking every day I pop my head out to look it it, jeese louise

Waiting for a new CCC to be fitted has kept me pretty much out of it, apart from the odd burn up I've not done many miles over the last two weeks

just wish a could sleep in it buddy but the t'other alf would be all jealous an that...

If you're going to pass a car doing 20mph and you're at 2500rpm what gear were you in ? I find a bit of turbo lag under 3000 but none over it 'coz the turbo's are spooled up already and at 4000 rpm it feels like my ///M engine for response. Were you in "Normal" mode, sport or sport+ ?

Sounds a little like my experience with my 35i manual. I hadn't really noticed the change properly but sometimes thought the throttle was a little odd as the car would dip in acceleration when gunning it. When i came back from my jaunt around Europe end June/July, about a week later, the engine management light came on, BMW said this was a minor issue to do with mixture and airflow meter but while i was waiting to get the car booked in the engine began to cut out completely. BMW had the car for a week, it took 2 days for the car to take the software upload! I did ask if Microsoft did the coding and was promised they didn't
At the end of the week and £1700 pounds of warranty work later i got my baby back with a 'we're not really sure what it was but we've replaced fuel lines to injectors, plugs, air flow meter etc so she should be fine'. The dealership did say that one of the turbos wasn't functioning properly and the other was compensating for it but they didn't know why.
What you have described sounds very similar to how my car reacted before conking out altogether. I guess mine had been playing up for 6 or 8 weeks before i realised there was a real problem. Silly i know but i just put it down to me not being so smooth on the gas and poss not being used to a turboed engine.

thanks for the input folks, cars in service right now and mentioned the issue to the technician, says he will look at it. will keep you informed