UPDATED::: Z4M S54 Engine Hesitation - POLL

TheRealDC · Post by **TheRealDC** » Sun Jul 15, 2012 8:01 pm

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 ..

RobertRO · Post by **RobertRO** » Mon Jul 16, 2012 6:01 am

53Fatman wrote: .. 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.

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 ... g=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 ... g=13&fg=15
This is the one you replaced with zero effect.

53Fatman · Post by **53Fatman** » Mon Jul 16, 2012 8:38 am

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

spareone3 · Post by **spareone3** » Mon Jul 16, 2012 9:33 am

53Fatman wrote: 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

http://www.z4-forum.com/forum/viewtopic ... 58#p523158 Yes me too..

original guvnor · Post by **original guvnor** » Mon Jul 16, 2012 11:13 am

This is a great thread Bertman.

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.

RedUn · Post by **RedUn** » Tue Jul 17, 2012 7:40 pm

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!

tomscott · Post by **tomscott** » Tue Jul 17, 2012 7:46 pm

Mines fine too 56 plate 51k

bertman · Post by **bertman** » Tue Jul 17, 2012 9:17 pm

Very interesting redun! Looking forward to an update in a few days

(Sent from my iPhone)

2dogs · Post by **2dogs** » Tue Jul 17, 2012 9:22 pm

Maybe we can have a throttle bliping at Zedfest to
see whats what

RedUn · Post by **RedUn** » Tue Jul 17, 2012 10:21 pm

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.

bertman · Post by **bertman** » Wed Jul 18, 2012 12:25 am

I think we're obto something here redun. I had my car flashed last week and Ive had word for word the same experience as you. Lets hope it keeps up as the miles build. This could be THE FIX

(Sent from my iPhone)

53Fatman · Post by **53Fatman** » Wed Jul 18, 2012 8:13 am

Please drive at least 500 miles with the new software, with some coldstarts and daily use.

If its still gone then, be happy

But a reset of the adaption (which ist definitely included in an softwareupdate) will help also for some time.

->

Karsten

daz05 · Post by **daz05** » Wed Jul 18, 2012 12:52 pm

Be good to get the TSB number listed on here to help others suffering as this proves it is an issue.

RedUn · Post by **RedUn** » Wed Jul 18, 2012 7:39 pm

bertman, Interesting that your finding is identical to mine! I noticed the colours on my sat nav were slightly different as well, the only other thing I have noticed is the exhaust sounds slightly different now, I'm sure it's less raspy? Maybe I'm loosing the plot!

53Fatman, I tried a throttle reset on it's own and it made no real difference so I'm hoping this flash has worked. I do use the car daily so the miles will soon rack up and I'll post updates to let you guys know if anything has changed.

daz05, I will wait to make sure it has worked first then I'll find out the TSB from the dealers? I don't want to give people false hope if it just goes back to normal

Shooter · Post by **Shooter** » Thu Jul 19, 2012 4:24 pm

Found this : http://www.automd.com/tsb/bulletin_b310538/ and this : http://www.automd.com/tsb/bulletin_b340127/
No further indication of the engine type, so...

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