UPDATED::: Z4M S54 Engine Hesitation - POLL

Poll Poll Does your Z4M S54 suffer from the engine hesitation from idle?

  • Yes, and I'd like it fixed

    Votes: 91 35.4%

  • It did, but it's fixed

    Votes: 15 5.8%

  • Yes, but it doesn't bother me

    Votes: 13 5.1%

  • Yes, but it only happens once in a blue moon

    Votes: 39 15.2%

  • No, I've never had this happen

    Votes: 99 38.5%
  • Total voters
    257
No problem on mine. '57 39k run exclusively on super. Usually Vpower

Though I think as Sammyz mentions- it is a highly strung NA engine putting out 343, it's like a racing car engine, a lumpy idle would be expected to some degree??

The people who have this- does it actually detrimentally affect driving ?
 
'06 car with 60.000 km, runs (since i have it) on different brands of fuel, but always SP98 (that would be something like Premium unleaded RON98 to you english guys), can be Total, Elf, Esso/Exxon, BP...
And i have the engine hesitation.

It affects driving in city. I have to be careful when arriving to a "give way", so i do not stall when i want to go.
 
The cams are very aggressive so a slightly lumpy idle is unsurprising. I use only V Power unless I absolutely cannot find a Shell station, and mine is rarely a problem. When I do have any hesitancy, typically it will be in heavy traffic in the rain after a good blast.
 
Going against the grain here , but I wack anything in so not always the 99 ron, so normal unleaded and still runs great!, when I put 102 ron in europe! jezzz thats good stuff :D :driving:
 
This is excellent guys 31 votes in only 24 hours and some great info in the thread

Based on your votes / comments & info from other threads I'm to piece together some facts about the problem

Facts I believe can be deduced from information submitted:
This is not a quirk of the S54 (62% of cars have never had it happen)
Mileage (Occurs on high and low mileage cars)
If the fault is in it's earlier stages, fuel can mask the problem (owners reporting being able to eliminate the fault by switching fuels)
The issue is progressive (some cars have had it happen but are able to eliminate it with different fuel, some can't)
Fuel is not the cause of the problem (owners without the fault reporting they can run their vehicle on low octane fuel without the fault)

Confirmed NON fixes:
ECU Flash
Clean MAF
Clean Idle Control Valve
Clean throttle body
Valve Lash
Oxygen / Lambda Sensor (taken from other thread)

Potential Fixes:
Coils
Clean injectors (not with a fluid but a proper remove & clean or replace)
Throttle position sensor
Throttle switch? (is this the correct name)
Accelerator pedal module
more...?


NB - I am not a BMW technical guru. I am just compiling and making assumptions based on presented info for the betterment of all owners and the forum
I've updated the 1st post so anyone new to the thread can see our conclusions to date
 
bertman said:
This is excellent guys 31 votes in only 24 hours and some great info in the thread

Based on your votes / comments & info from other threads I'm to piece together some facts about the problem

Facts I believe can be deduced from information submitted:
This is not a quirk of the S54 (62% of cars have never had it happen)
Mileage (Occurs on high and low mileage cars)
If the fault is in it's earlier stages, fuel can mask the problem (owners reporting being able to eliminate the fault by switching fuels)
The issue is progressive (some cars have had it happen but are able to eliminate it with different fuel, some can't)
Fuel is not the cause of the problem (owners without the fault reporting they can run their vehicle on low octane fuel without the fault)

Confirmed NON fixes:
ECU Flash
Clean MAF
Clean Idle Control Valve
Clean throttle body
Valve Lash
Oxygen / Lambda Sensor (taken from other thread)

Potential Fixes:
Coils
Clean injectors (not with a fluid but a proper remove & clean or replace)
Throttle position sensor
Throttle switch? (is this the correct name)
Accelerator pedal module
more...?


NB - I am not a BMW technical guru. I am just compiling and making assumptions based on presented info for the betterment of all owners and the forum
I've updated the 1st post so anyone new to the thread can see our conclusions to date
Click to expand...

Excellent response this research is important hopefully over time a solution can be found for suffers and save a lot of ££££ in the process. More input more accurate the data :)

Mods could this be a “sticky” or something??? What the thoughts out there? e.g like the springs one??
 
bertman said:
Potential Fixes:
Coils
Clean injectors (not with a fluid but a proper remove & clean or replace)
Throttle position sensor
Throttle switch? (is this the correct name)
Accelerator pedal module
more...?
Click to expand...

Hi Guys,

here in Germany are at least 10 People that i know who have this problems:

- Engine do not rev directly from idle, like a little misfire or something. Really annoying, sometimes on my car is it so bad that it nearly stalls when you do it more then one time instantly. It feels like you say a hesitation till it goes with full power.

- The "RPM Dip" when you push the clutch when you are under ~2000rpm. The rpm falls below the idle rev without stopping and sometimes it nearly stalls. Its easy to reproduce, just a hint of throttle to under 2000rpm and then it falls. Sometimes more, sometimes just a little.

What i have done is this:

- new coils and sparks (BMW OEM) -> feels a little better on cold starts with temp <15°, there was really a little misfires with cold motor in idle. But there where never faults saved on the ECU. More like placebo effect, rpm dip and hesitation unchanged.
- MAF switched with a used one from a E46 M3 -> nothing
- idle valve changed to new one (BMW OEM) -> nothing

now we are getting closer, i changed the throttle position switch at the front of the engine besides the first throttle housing -> nothing, but..

.. a few weeks ago a guy from "our" german "M-Forum" called me and said he had the problem solved with changing the TPS under the airbox, the one on the electric throttle actuator, on two cars. Maybe it is the solution but i cant confirm it because at the moment i dont have the time to switch my TPS and i dont have the tools to get the airbox removed.

So if you want to change a TPS start with the one under the airbox.

What i noticed by the way is that a reset of the throttle adaption works for a short time of miles (maybe 400 to 1000km) but the problem will come back, every time.

Regards

Karsten
 
never had it im in 07 coupe with 56k on the clock always run on 99 tesco or v power , tried shell 102 but to be honest felt no difference as from my reading you need at least 3 fills so the ecu can "taste" the difference as it were , this was definetely the case in my major modded tt
 
Posted my response as I did have the issue. Sold the car 2 years ago, because I got really p***ed at local dealer response to issue. Dealer took car in and diagnosed "run car on V-power". Sorry, but having owned 4 M3's previously (and ran them all on regular unleaded from various sources) with no such issues (total mileage circa 135k) I wasn't convinced and the car still had the symptoms. I still browse these threads and post occasionally as I loved my MC, but the brand used to be about customer service and that seems to have disappeared over the years to the point that I won't own another BMW until they regain their old customer service values and attitude ... :( Sorry, but this is all about sharing experiences and thats how unhappy I was with the response .. didn't help that they added 2 scratches to the car and used half a tank of fuel ...


DC

p.s. they did reset the throttle and it was slightly better for a couple of hundred miles ..
 
53Fatman said:
.. a few weeks ago a guy from "our" german "M-Forum" called me and said he had the problem solved with changing the TPS under the airbox, the one on the electric throttle actuator, on two cars. Maybe it is the solution but i cant confirm it because at the moment i dont have the time to switch my TPS and i dont have the tools to get the airbox removed.
So if you want to change a TPS start with the one under the airbox.
Click to expand...

Excellent feedback, Karsten.
As I understand, the TPS on the throttle actuator which must be changed is p/n 13637840383, pos. #3 in the picture:
http://www.realoem.com/bmw/showparts.do?model=DU91&mospid=49422&btnr=12_1103&hg=12&fg=10
This is the one you suggest to replace.

The other TPS, located on the throttle bodies has the same p/n, pos/ #2 in the picture:
http://www.realoem.com/bmw/showparts.do?model=DU91&mospid=49422&btnr=13_0911&hg=13&fg=15
This is the one you replaced with zero effect.
 
Exactly, there is a third one in the accellerator pedal. This one you can imho only change by replacing it with a new complete pedal.

The part number is the same for the TPS at the front and the one on the actuator.

There is one guy in our forum, he tried to explain to me how the system "Pedal - ECU - 2xTPS" works, but i dont understand it completely. He said on the older engines (S50B30/32) that only have one TPS because of having NO E-Gas (dont know if it called E-Gas in England/US, i mean that there is a directly connected accelerator pedal to the throttle valve(s)), are running really worse when the TPS went bad, because there is no second TPS to check again and correct.

For me as beeing not a mechanic it quite sounded right at the first time someone said "Could it be the TPS?". Its just a potentionmeter who measure the throttle valve opening in percent. When the poti went bad and has some bad spots or is hanging the air fuel ratio will get to rich or lean and you got the feeling it chokes and nearly stalls.

I really hope it is the solution.

Karsten
 
This is a great thread Bertman. :thumbsup:

I have a 32k miles 07 and have never had this issue. My car runs on V-Power for 95% of the time.

Thanks to the people who have contributed their experiences I will now know where to start looking if I ever encounter the issue.
 
Some extra information for your thread.

My cars a 56 reg with 22k on the clock.

It had the hesitation at low revs, blip the throttle and it would miss.

Until today I have cleaned the MAF, throttle reset, put two fuel cleaners through it and had the plugs changed. This made the car much smoother to drive but it was still the same.

I had the car at the dealers today for something else and mentioned about the problem and they managed to find a TSB relating to this exact issue. The answer from BMW is to flash the car with updated software which he has done.

I've only driven the car home so far but as far as the hesitation goes it's completely gone?! I'm going to take the car out now for some fuel and a blast, i'll report back with any further findings!
 
40 mile update - so far so good, the hesitation has definitely gone!

So far the car revs (blips) much quicker and cleaner than before and it is also much smoother through the rev range. I initially thought it felt slower but I think it's just the extra smoothness?

Also I don't know if my car had a non standard map before as the throttle was very jerky, with the sport button on it was basically un-driveable it was like an on-off switch, now the sport button is actually useable!

I'm at Zed Fest on Saturday, I'm up for some blipping, it would be an interesting comparison.

I will report back once I get to 100 miles.
 
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