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My car suffered periodically from the hesitation but it wasn't that often and I learned to drive round it. After two O2 sensors were replaced under warranty the hesitation has completely gone. Who knows if this is a cure but worth considering anyway.

Hi all,

I bought my Z4MC approx 12 months ago and experienced from day 1 the hesitation and idling issues described here. After spending a reasonable amount of money with an independent BMW specialist (who as it turns out is okay with standard BMWs but has no clue of how to work with S54 M cars) I was still experiencing this issue and getting quite frustrated with it.

With the fine work and how-to info of the good folk here I managed to resolve it myself by freeing up the ICV. The car now runs like an absolute dream. No hesitation. Idle sits like a rock on 900 RPM.

Thanks to those who give their time and expertise here. My car now runs like it should!

Cheers

Dan

Noticed an issue with me M, wondering if it's this.

When cold, the car is hessitant until 3k, and engine braking is very aggressive (it slows down very quickly when not on gas). I know it's thick oil, but I don't remember it doing this before the last few weeks. It's also due an I2 in 3k.

It's under warranty, and I'm tempted to throw it in for it's service earlier along with this issue.

I've started to note something similar to this on mine. 59k Roadster, driven a few K per year as a weekend toy. Also runs a GruppeM filter.

It starts everytime and doesn't waiver from 900 rpm on idle (no hunting). However, I find if I take my foot off the pedal around town, it will dip below 900 revs and then return. It has never stalled on me (touch wood) but if I am in, say, second gear and go WOT from 1.5k revs I can make the car jump quite violently as it seems to "catch up with" my throttle input.

From reading the (excellent!) info in this thread, this sounds like a TPS issue, so possibly should be my first port of call?

I neever had this issue with mine(posted as such on this thread,back in 2012),but it started doing it and was spoiling the otherwise excellent driving experience a wee bit...
So I took it to my BMW Indy las week,and asked him to remove and then clean the Idle control valve, which I can safely say has cured the issues I was having with hesitation/spluttering at upto about 3k rpm,as well as eractic idling.

The car is now back to driving as good as it always did,so if anyone else is having these issues,worth cleaning the icv first

craig3.2 wrote:I neever had this issue with mine(posted as such on this thread,back in 2012),but it started doing it and was spoiling the otherwise excellent driving experience a wee bit...
So I took it to my BMW Indy las week,and asked him to remove and then clean the Idle control valve, which I can safely say has cured the issues I was having with hesitation/spluttering at upto about 3k rpm,as well as eractic idling.

The car is now back to driving as good as it always did,so if anyone else is having these issues,worth cleaning the icv first

Thanks for the input, Craig. I've decided to spend a bit of time on preventative maintenance and love for mine, so have ordered a new MAF, TPSx2 and will clean the ICV while I have the car apart. Means it's given a nice new bill of health!

Resurrecting an old thread has anyone got to the bottom of the revs at idle issue? My car feels like it's about to stall when I depress the clutch and then bounces back to idle

No probs with mine but saw many with the problem when looking for one to buy.

ratty64 wrote: ↑Sat Jul 08, 2017 5:27 pm Resurrecting an old thread has anyone got to the bottom of the revs at idle issue? My car feels like it's about to stall when I depress the clutch and then bounces back to idle

One of these will be the culprit, ordered by what I would do/check/replace first.

Idle control valve. This should open and close freely to allow enough air to bypass the closed throttle flaps to keep the engine idling correctly. They gunge up and need periodic cleaning, due to their location (under the big air plenum) this seldom happens. You could try taking the top pipe off and generously spray carb cleaner down it a few times over a week or so, or remove the air plenum to then remove it and clean it up properly or replace with a new one. Whilst off you can also clean the throttle bodies. A few guides exist on the web on how to do this with pictures.

Throttle position sensors; one of the front of the the throttle butterfly bar (next to oil canister lid) and another the throttle actuator (again under the air plenum) - they are simple potentiometers and just wear out. I changed both but thinking back I suspect cleaning the idle valve made the biggest difference.

Air Flow Meter (mine was replaced under warranty a few years ago, it did not cure the idle bounce but generally drove better after with slightly better mpg too).

Hi !

Read all over the 24 pages here.

Just bought a 2007 z4m with 11.000 Km and this thing is happening.

There´s only 5 in my country and no ones knows how to fix it. I´ll just buy everything you guys mentioned here and i´ll do it by myself. By the way, thanks for sharing all the information and all the work you did.

I didnt see any links for the parts, can any of you confirm it?

This is the TPS sensor? (I need two of these, right?)

https://parts.bmwofsouthatlanta.com/pro ... 40383.html

Idle Control Valve

https://parts.bmwofsouthatlanta.com/pro ... 33090.html

Intake Camshaft Sensor

https://parts.bmwofsouthatlanta.com/pro ... 39171.html

Throttle actuator

https://parts.bmwofsouthatlanta.com/pro ... 40537.html

Thanks again!

enzotieppo wrote: ↑Thu Feb 22, 2018 4:59 pmHi !


Idle Control Valve

https://parts.bmwofsouthatlanta.com/pro ... 40537.html

That link is for a throttle actuator

Hi enzotieppo. Well done for choosing the Z4M. Where are you based? You should introduce yourself in the newbies forum and post some pics

Sure !

I´ll do that, thanks for the tip.

I´m in Brazil, we have here 5 roadsters and another 6-7 coupes z4m.

Spaniarduk wrote: ↑Thu Feb 22, 2018 11:46 pmThat link is for a throttle actuator

https://parts.bmwofsouthatlanta.com/pro ... 33090.html

Sorry... Here is !

Bump. Good thread. My car is doing this badly again after being laid up for a while.

I will remove the idle control valve when I get a chance and clean it or quite possibly just replace the poxy thing.

There is something very different between the Z4M and E46 M3 S54 implementations in this respect because E46 M3 does not do this.

I know the engine management systems are different and it must be something related to the different programmes which are running between the two cars in my opinion.