mad4slalom
Senior member
lllu m pppy tttckover --- d--d--dd--ont kn kn--ow wwwh -at yyyou mmean 
UPDATED::: Z4M S54 Engine Hesitation - POLL
- Thread starter bertman
- Start date
mad4slalom said:lllu m pppy tttckover --- d--d--dd--ont kn kn--ow wwwh -at yyyou mmean
"Computer can't find any problem to fix but we agree from the test drive that something isn't right" helpful Cooper Chelmsford... Very helpful.
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I always ran with she'll v power and had no problems at all. With the snow and bad weather I started using she'll fuel save instead of the v power as I wouldn't be using the power, now my car doesn't feel as it did before and there is slight hesitation on throttle, next full up I'm going back to v power!
Mine has hesitated once or twice whilst I've owned it, 27 months, and only when it's cold
Adam D said:Replaced the front sensor on the throttle bar and the throttle is very smooth now but not a night and day change like when the switch on the throttle actuator was replaced (this one seems to cause the stumbling and idle issues).
Any chance you could link a picture and part no. (if different) for the front TPS? I only replaced the one on the actuator under the air box.
spareone3 said:Adam D said:Replaced the front sensor on the throttle bar and the throttle is very smooth now but not a night and day change like when the switch on the throttle actuator was replaced (this one seems to cause the stumbling and idle issues).
Any chance you could link a picture and part no. (if different) for the front TPS? I only replaced the one on the actuator under the air box.
Hi there,
It's the same part number but if you are looking at the oil filter housing then the front switch is bolted to the end of the throttle bar just behind it
the wire should give it away.Will try to get a photo if you still have trouble finding it.
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Hi everyone. Have a 57 plate Z4M, done 25,000 miles in it taking it to 35,000 miles. The hesitation is indeed irritating. Doesn't do it on sport mode, but that setting is too manic for me. The splutter is everything people say here, and I generally go careful on roundabout take-offs in any gear. Stalls in reverse sometimes, but never stalls in forward gears. I found it pretty much went away for about 3,000 miles with new plugs, but could have been the throttle reset. I've never been able to get any improvement from resetting the adaptive throttle but may not have been doing right. Petrol makes no difference, all types and even 95 the same. Notice no difference in different weathers. A few times it caused a misfire type effect slowing in third and taking off again, transmission bang. Had 2 stroke motorcycles with mich better throttle response from idle, expected better from this car. Get some relief after thrashing it for 40 miles or so, very fast, then all seems to tighen up and hum, until 10 miles of urban driving then back to its ways. Good luck everyone!
Tony
Tony
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Anonymous
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Just stumbled across this thread whilst trying to find out about an issue with my Z4MR.
I think my car has this issue. I do not have any problems with idle stability or quality however . . . . . . example would be if I am approaching a roundabout in second gear on the overrun, clutch fully out and engine speed at idle or 100RPM above . . . . . when I quickly feed in a bit of throttle . . . . . . nothing happens and then the car splutters into life again and jerks nastily into action . . it is like a severe hesitation when transferring between a closed throttle to a reasonable throttle opening at low RPMs.
I will try resetting the throttle adaptations tomorrow and see if that resolves it for a while.
If it does, chances are I need to change the lower TPS?
I think my car has this issue. I do not have any problems with idle stability or quality however . . . . . . example would be if I am approaching a roundabout in second gear on the overrun, clutch fully out and engine speed at idle or 100RPM above . . . . . when I quickly feed in a bit of throttle . . . . . . nothing happens and then the car splutters into life again and jerks nastily into action . . it is like a severe hesitation when transferring between a closed throttle to a reasonable throttle opening at low RPMs.
I will try resetting the throttle adaptations tomorrow and see if that resolves it for a while.
If it does, chances are I need to change the lower TPS?
Before I changed both my TPS's I had the issue above, which has now disappeared for good (for over a year now). I also cleaned out the ICV & throttle bodies at the same time so this may also have helped sort out the issue. The TPS's feel pretty fragile so I wouldn't be surprised if the wear out after a few years.
ChawenHalo said:
UPDATE: had the valve clearance and shim done. Car runs perfect and very smoothly. Still stalls from time to time with no warning but apparently that's a known bug to do with the idle control or as you guys mention the TPS.
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Anonymous
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So, I did this on Saturday. The car was significantly improved but still not perfect.
Today I decided to investigate further, so I swapped the upper TPS, on the end of the throttle rail with the (lower) one removed from the throttle actuator.
The throttle hesitation issue immediately worsened.
Seeing as they are the same part and one has definitely worn out somehow, it is very likely the other has too.
I have therefore taken the plunge and bought another TPS. With the right voucher code plugged in, euro car parts are doing them for 25% discount at the moment so they work out under £40 each.
Today I decided to investigate further, so I swapped the upper TPS, on the end of the throttle rail with the (lower) one removed from the throttle actuator.
The throttle hesitation issue immediately worsened.
Seeing as they are the same part and one has definitely worn out somehow, it is very likely the other has too.
I have therefore taken the plunge and bought another TPS. With the right voucher code plugged in, euro car parts are doing them for 25% discount at the moment so they work out under £40 each.
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Anonymous
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So, a couple of months down the line and we are back pretty much to where we were before.
Hesitation and splutter at low RPM in second gear which can be very disconcerting when coming up to a roundabout give way on the over-run and then command some power, upon which the car splutters for a second then thrusts violently into life again.
Quite annoying to be honest and spoils the car.
So the throttle position sensors have NOT cured this issue for me. At the time, things were much better but this is probably down to clearing the adaptations as the issue slowly re-appeared over the next 500 miles or so with each TPS change.
After many hours of research and mucking about, I have today used WINKFP to update my cars DME software to the latest version available, from the 2013 Daten V50.2 files).
For information, my car is a March 2007 build.
Just before the update, the car showed the current DME software version what would be the new DME software version. I did not take a note of the old version ( :x ) but I can say that the current Software had a much lower revision number than the new software I installed (7840449).
I am pleased to say that it installed OK and throttle response is immediately totally different.
I will update this thread after 500 miles or so but looking good so far.
Hesitation and splutter at low RPM in second gear which can be very disconcerting when coming up to a roundabout give way on the over-run and then command some power, upon which the car splutters for a second then thrusts violently into life again.
Quite annoying to be honest and spoils the car.
So the throttle position sensors have NOT cured this issue for me. At the time, things were much better but this is probably down to clearing the adaptations as the issue slowly re-appeared over the next 500 miles or so with each TPS change.
After many hours of research and mucking about, I have today used WINKFP to update my cars DME software to the latest version available, from the 2013 Daten V50.2 files).
For information, my car is a March 2007 build.
Just before the update, the car showed the current DME software version what would be the new DME software version. I did not take a note of the old version ( :x ) but I can say that the current Software had a much lower revision number than the new software I installed (7840449).
I am pleased to say that it installed OK and throttle response is immediately totally different.
I will update this thread after 500 miles or so but looking good so far.
I'm guessing that if you updated the ECU you will have overwritten all the fuel trims, adaptions and any other learning by the ECU and gone back to a start situation. However, unless it is a software issue, whatever sensor that is giving duff info to the ecu which is then 'learning' from duff info that creates the poor running is still providing duff info and the problem will just come back over time.
I had a complete ecu reset at my inspection 1. All the adaptions the ecu had made to the fuel trim and throttle maps etc were wiped and the car felt amazing. Unfortunately the same running problems started to reoccur over the next 3-4k miles.
I had a complete ecu reset at my inspection 1. All the adaptions the ecu had made to the fuel trim and throttle maps etc were wiped and the car felt amazing. Unfortunately the same running problems started to reoccur over the next 3-4k miles.
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Anonymous
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Lower said:
Yes I agree with what you are saying and time will tell. It is possible that some of the ECU programmes had a "glitch" however in terms of the learning and this is what gives the problem.
For the moment the car is running great.
It is another issue I know but the newer programme is definitely MUCH better in cold start conditions.
I have an intravee fitted which I can use to see the coolant temperature. On a cold start, the car used to be very "jumpy" and juddery when under load until the coolant temperature hit 50 degrees. It felt like the car was running too lean somehow for a short time during warm up and gave some jumpy behaviour.
Since the software update, this warm up bad behavior is almost completely gone and it is driving like a different car so I live in hope for the moment.
Your car sounds exactly like mine. Its pretty lumpy when its cold, particularly around 2k revs and then has the hesitation when warm, although mine is not so bad when warm.
However, when i had the ecu cleared of all learning the engine felt like a different engine when cold and warm. Unfortunately the unpleasant symptoms came back as the ECU 'learnt' again. In fact i could feel them start to come back in a very minor way within 250 miles.
I had the specialist that did my recent oil service check the outputs from both o2 sensors (i'm on the originals at 35k miles) and the throttle position sensors and the outputs were correct and linear. I've also had a new MAP sensor and that didn't make any difference either.
Lets hope your fix is permanent! Please keep this thread updated.
However, when i had the ecu cleared of all learning the engine felt like a different engine when cold and warm. Unfortunately the unpleasant symptoms came back as the ECU 'learnt' again. In fact i could feel them start to come back in a very minor way within 250 miles.
I had the specialist that did my recent oil service check the outputs from both o2 sensors (i'm on the originals at 35k miles) and the throttle position sensors and the outputs were correct and linear. I've also had a new MAP sensor and that didn't make any difference either.
Lets hope your fix is permanent! Please keep this thread updated.
Although my car doesn't have the hesitation problem, I'm interested in the idea of having my DME updated to the latest software version. Are you able to give me a couple of pointers to where I can find the latest version of WINKFP and, more importantly, the Daten files? (I already have an OBDII cable and have used SSS and NCSexpert in the past).sniffer said:
Also: I assume that BMW dealers wouldn't update this software as part of a service, but only in response to a particular problem?
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Anonymous
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ZedFourM said:
Let google be your friend to get daten 50.2 "bmw daten 50.2".
BMW dealers would not update the cars DME software unless they really had to, as you say, probably if they were trying to resolve an issue and were advised by HQ / PUMA, etc to do so
Thanks, that's helpful. I think that I probably need to do a lot more reading up on the topic before I have a go at updating my DME - I don't want to risk "bricking" my car
How is your car? Have the improvements that you noticed when you upgraded the firmware remained, or is it gradually going back to its bad old ways?
How is your car? Have the improvements that you noticed when you upgraded the firmware remained, or is it gradually going back to its bad old ways?
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Anonymous
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ZedFourM said:Thanks, that's helpful. I think that I probably need to do a lot more reading up on the topic before I have a go at updating my DME - I don't want to risk "bricking" my car
How is your car? Have the improvements that you noticed when you upgraded the firmware remained, or is it gradually going back to its bad old ways?
Absolutely. Do not do anything until you are totally comfortable with what you are doing. The last thing you would want is to break the car.
In terms of my car, it is is a different car in terms of the cold warm up jerkiness issue and general drive-ability since the DME update.
However, the issue we are talking about on this thread, the engine hesitation / flat spot at low RPM had come back once more.
I took some time to think about it this morning and believed that it must be related to the inlet set-up and some degradation over time of something, perhaps the airflow pattern through the throttles.
I therefore today took the time to disassemble and clean the inlet manifold, throttle bodies including the mechanism and springs, inlet trumpets and all of the idle control system pipework. I took it slow and took several hours, with a toothbrush, kitchen roll and two cans of carb / inlet cleaner.
Nothing looked to be too bad in the first place (2007 car with 35K miles) but it all cleaned up very well, like new in fact. I used a lot of cleaner down the removed idle control valve and pipework which is of relatively small diameter in places and more likely to gum up. The cleaner did not run through easily at first and when it did, came out very black. After a few minutes it was much better.
For the record, I have not had any issues whatsoever with my idle speed or control but I wanted to make sure everything was totally clean because the idle bypass system is a bit different on these cars because of the individual throttle bodies. We don't really know what the DME is telling the idle control valve to do at low RPM when you jab the throttle. . . . .
Anyway, I have put it all back together and fired it up, it took a while to start as I guess the cylinders had some carb cleaner in them.
I have not cleared any adaptations or anything. Immediately, when revving in the drive the pickup from idle was significantly cleaner.
I took it for a 15 mile drive just now and pretty much continuously trying to recreate the issue was unable to do so over various engine oil temperatures.
I would be surprised if this has resolved it, but after having it all apart I guess it is very possible. The entire engine, it's airflow in particular is really pushing the envelope for a day to day car so perhaps a small degradation or change to the airflow characteristics could throw this fault. As I said earlier, the idle by pass setup is quite complex in terms of the air routing due to the individual per cylinder throttles and we do not know what the DME is getting the idle control valve to do at low RPM's. . . .
Also, in the process of cleaning the inlet trumpets, the fuel injection ports are also cleaned together with the tips of the fuel injectors where they fire into the inlet of each cylinder.
I will keep this thread updated but am currently hopeful that this has now cured it.