UPDATED::: Z4M S54 Engine Hesitation - POLL
- Thread starter bertman
- Start date
Do you have first hand experience of this then?ph001 said:
In the 4 years I had my m3 I never came across this symptom on any of the various boards, some which I still frequent and I still don't hear of it?
My z4m had this problem when I bought it, thankfully I fixed it shortly after although I'm still not quite sure how. 4 years on still good.
It's a horrible problem though, really detracts from the experience.
I'm also of the opinion that it's the dme used in these cars which causes the problem and is very different to the e46 dme.
TomK said:
...ah, apologies. Yes can confirm that when the E46 M3 warms up there is no hesitation. Like you say though, all the engine hardware apart from the ECU and exhaust is the same so makes you think software related. Has anybody had a remap from the likes of Evolve? If that sorts it then it confirms software really.
Ok so Hi everyone.. Car=Z4MC. I came upon this thread whilst looking for a fix to my problems which appear to be exactly as headlined. I only just purchased the car and it has 77,000km. During the test drive the car performed flawlessly but after a couple of weeks this hesitation started happening and has progressively gotten worse.
Once my car has had it's hesitation from idle then it purrs and screams like it should! So when stopped I usually give the car revs earlier than normal prior to releasing the clutch just so it has it's little hissy fit before the clutch is released. Once its had it's fit then all good.
The day I purchased the car I scanned it for faults and 002C9D (Lambda heater fault) showed up. The car has low k's and is in pretty clean shape under the bonnet. At least the car is reliably hesitating after warm up,,, well up until today anyway. I was so happy that the car wasn't doing it today and it was a pleasure to drive again. The only thing I did was to remove the engine cover and disconnect the 2 lambda sensors from the harness, and remove all coil packs to inspect them. Sure enough one of the Lambda sensors measured open circuit across the heater element. The coil packs looked ok and down the holes looked nice and dry. I re-installed the coil packs and re connected the lambdas. I went out for a drive and I noticed that the car was behaving and responding nicely to throttle activation, making heal & toe simple again. I can't for the life of me understand why this problem has gone at least for now but I suspect the problem will raise it's head again soon.
I have ordered new lambdas, TPS x 2, Spark plugs, Coil packs x 6, just because I want these new now. Last week I changed the MAF sensor. Later this week or weekend I will be replacing the other parts and will also give the ICV a good clean. If the car starts playing up again then I shall replace each part progressively to try and learn something. Until this morning I was pretty convinced it was the ICV.
Will try and keep the forum updated with my progress, or lack thereof.
Once my car has had it's hesitation from idle then it purrs and screams like it should! So when stopped I usually give the car revs earlier than normal prior to releasing the clutch just so it has it's little hissy fit before the clutch is released. Once its had it's fit then all good.
The day I purchased the car I scanned it for faults and 002C9D (Lambda heater fault) showed up. The car has low k's and is in pretty clean shape under the bonnet. At least the car is reliably hesitating after warm up,,, well up until today anyway. I was so happy that the car wasn't doing it today and it was a pleasure to drive again. The only thing I did was to remove the engine cover and disconnect the 2 lambda sensors from the harness, and remove all coil packs to inspect them. Sure enough one of the Lambda sensors measured open circuit across the heater element. The coil packs looked ok and down the holes looked nice and dry. I re-installed the coil packs and re connected the lambdas. I went out for a drive and I noticed that the car was behaving and responding nicely to throttle activation, making heal & toe simple again. I can't for the life of me understand why this problem has gone at least for now but I suspect the problem will raise it's head again soon.
I have ordered new lambdas, TPS x 2, Spark plugs, Coil packs x 6, just because I want these new now. Last week I changed the MAF sensor. Later this week or weekend I will be replacing the other parts and will also give the ICV a good clean. If the car starts playing up again then I shall replace each part progressively to try and learn something. Until this morning I was pretty convinced it was the ICV.
Will try and keep the forum updated with my progress, or lack thereof.
Got the problem but not on my Z4MC. E46 330CI MSport has behaved this way for some time. M52B30 engine same as in the non M pre-facelift 3 litre Z4. Misfire when picking up from idle or on the overun. The blogs all reckon it is a leak in the crankcase breather system. I have done:-
New DISA valve;
New CCV valve;
New crankcase breather pipes.
Still no cure. Thinking plugs next or maybe airflow sensor.
New DISA valve;
New CCV valve;
New crankcase breather pipes.
Still no cure. Thinking plugs next or maybe airflow sensor.
An update..
Have just replaced the spark plugs, coil packs, throttle body TPS with all new genuine parts. Car is still doing it. Next on list hopefully sometime this weekend is cleaning ICV, replace lower TPS. And on Monday when my new o2 sensors come then those.
I really feel it's the ICV as it can sometimes be good on one blip of throttle but most the time it is bad, which makes me think the ICV is a little sticky. Would have done it first if were not quite such a pain the backend.
Report back soon...
Have just replaced the spark plugs, coil packs, throttle body TPS with all new genuine parts. Car is still doing it. Next on list hopefully sometime this weekend is cleaning ICV, replace lower TPS. And on Monday when my new o2 sensors come then those.
I really feel it's the ICV as it can sometimes be good on one blip of throttle but most the time it is bad, which makes me think the ICV is a little sticky. Would have done it first if were not quite such a pain the backend.
Report back soon...
Another update..
Thoroughly cleaned ICV, hoses, throttle bodies, butterflies. Replaced the throttle actuator sensor, inspected all lines. Problem persists. Bugger!
The ICV didn't really feel a concern when I initially removed it but once or twice I thought it was a little hesitant to move when shaking from side to side but that could have been where it was balance at the time and direction of the shake.
The procedure is not as bad as I thought. It probably took about 30 minutes to remove / disassemble, 60 minutes to clean, 60 minutes to reassemble, 10 minutes to feel disappointed about wasting my time.
Tomorrow my Lambda sensors arrive and will do the pre and post cats. If this fails to cure the problem then I don't know, maybe I will focus on the VANOS. FU&^^&%^%$%45.
Thoroughly cleaned ICV, hoses, throttle bodies, butterflies. Replaced the throttle actuator sensor, inspected all lines. Problem persists. Bugger!
The ICV didn't really feel a concern when I initially removed it but once or twice I thought it was a little hesitant to move when shaking from side to side but that could have been where it was balance at the time and direction of the shake.
The procedure is not as bad as I thought. It probably took about 30 minutes to remove / disassemble, 60 minutes to clean, 60 minutes to reassemble, 10 minutes to feel disappointed about wasting my time.
Tomorrow my Lambda sensors arrive and will do the pre and post cats. If this fails to cure the problem then I don't know, maybe I will focus on the VANOS. FU&^^&%^%$%45.
Ok so today I replaced the 2 pre cat Lambdas and the problem persists. Now it feels like 
The Lambda sensor that had a faulty heater as I mentioned in my initial post had quite a bit of carbon deposit on it when the good one was fairly clean which suggests to me that the faulty heater had caused damaged eventually to the sensor so it reports incorrect values to the DME and therefore the DME is running that bank rich when it thinks it is not. Thought I was on to something there until
.
The Lambda sensor that had a faulty heater as I mentioned in my initial post had quite a bit of carbon deposit on it when the good one was fairly clean which suggests to me that the faulty heater had caused damaged eventually to the sensor so it reports incorrect values to the DME and therefore the DME is running that bank rich when it thinks it is not. Thought I was on to something there until
.What I have noticed though is that if I disconnect the MAF sensor then things are perfect but I guess doing this just means the DME is running in open loop mode. But it's interesting and probably points far away from there being a VANOS problem and more likely to be a sensor or leak problem.
Spaniarduk
Member
Buzzard88 said:
[ref]Buzzard88[/ref], I'm following your progress with interest! As for the VANOS.... you may want to have a look at the following link and subsequent pages after that one. In particular the comments from [ref]Attilio[/ref] .
Let us know how you get on after youve replaced the pre- and post-cat O2 sensors
So I still haven't done the post cat sensors yet, but today I replaced all injectors with new units and still the same which is what I suspected would happen.
I can't help but keep going back to disconnecting the MAF sensor and everything is fine. From my understanding disconnecting the MAF sensor should run the DME in open loop mode??? Can anyone confirm this? Can anyone also confirm what sensors are ignored in open loop mode?
This week I will get around to doing the post cat sensors but I think they have no feedback on how the DME prepares the fuel & air.
I can't help but keep going back to disconnecting the MAF sensor and everything is fine. From my understanding disconnecting the MAF sensor should run the DME in open loop mode??? Can anyone confirm this? Can anyone also confirm what sensors are ignored in open loop mode?
This week I will get around to doing the post cat sensors but I think they have no feedback on how the DME prepares the fuel & air.
Spaniarduk
Member
I always thought the post cat sensors are there to feed back to the ecu and, if required, the ecu will make the engine run incrementally leaner for a given amount or air (there is the feedback from the air mass sensor) until such post-cat sensors are 'happy' with what they 'sniff' past the catalytic converters... i could be wrong, though.