UPDATED::: Z4M S54 Engine Hesitation - POLL
- Thread starter bertman
- Start date
AndyBeech said:
I think that there must be one solution for this. There are many cars with this fault and many without, that could not be accidentally.
Sometimes i think the hesitation from idle and the dip when the revs going down is quite the same problem, sometimes i think its not related. Fact is, when you disconnect the MAF the hesitation is completely gone. At least my car revs freely then. But the dip occurs unchanged. And the hesitation on my car was really bad, and the dip is still bad and not a slightly symptome like on other cars.
I disambled the complete air intake many times, and the hesitation is definately better than it was. Like 10-20% as bad. This could be the bad connector contact. But maybe this is not the reason for the hesitation, maybe its just curing the symptomes.
The faulty earth that he mentioned could affect all electrical components, maybe the MAF is the only one that is so sensitive to a slightly higher resistance?
I will not give up the hope. Love the car to much for that
Regards
Karsten
Did a nice drive today because of the nice weather (10°C and sunny) and thought i should test that thing with the MAF connector.
The drive was "okay", like it was before the winter. Slight hesitation from idle and of course the idle dip...
After the car was back in the garage i turned the engine off und disconnected/reconnected the MAF a few times to see if there is a difference. There was, the hesitation was now really bad again :thumbsdown:
I closed the garage and went away :x
There is definitely something wrong with this part/connection. But the idle dip was unchanged.
Regards
Karsten
The drive was "okay", like it was before the winter. Slight hesitation from idle and of course the idle dip...
After the car was back in the garage i turned the engine off und disconnected/reconnected the MAF a few times to see if there is a difference. There was, the hesitation was now really bad again :thumbsdown:
I closed the garage and went away :x
There is definitely something wrong with this part/connection. But the idle dip was unchanged.
Regards
Karsten
Did we ever hear any further on the faulty earth situation? I have noticed some odd behaviours, albeit very small, in some of my cars electrical bits and pieces. I had a number plate light flickering after the car was turned off and locked, I had the brightness of all my dash lights dim for about 1 second and then pick up again. It could also explain a slightly unenthusiastic start-up.
An electrical issue could be a possibility.
An electrical issue could be a possibility.
53Fatman said:
Yup, there is deffo something up with the MAF/MAF connector. Usually my cold start has always taken a couple of cranks, nothing out the ordinary to be fair.
Today as I have a spare MAF hanging around, I tried the bending the pins on the MAF by about 5 degrees trick mentioned earlier in the thread, took the new one off and connected the 'bent pins' one. Connection was slightly tighter putting it back on but all good. Car was stone cold, not used for a day, so turned it over and literally didn't even crank once, a split second from turning the key and it started, sounding good! Massively taken aback by this as I've never known a car start so quick from cold!
Might have been a fluke but from 8 months of ownership that's never happened, took it for a drive and it all seemed excellent, even the idle dip seemed to disappear. It slowly came back though, and by the time I got back home the slight dip had returned. Bizzare, but there's deffo something in the whole MAF connection probably deteriorating over time. Might give the contact enhancer a shot when I get a bit of time as I genuinely thought the 'problem' was fixed.
Seeing as I've been quite active on this topic, I can now report my hesitation is fixed!
Using the technique described by I think 'Meeko' earlier in the thread, I got myself some Stabilant 22, quite expensive but turned out to be worth it!
I disconnected the MAF, used a load of contact cleaner on the MAF side and on the connector, let that dry out then added the Stabilant 22 solution to both the MAF male connectors and the female connector, then re-assembled. I noticed straight away the car pulled better with no hesitation, started better and it's got better every time I've used the car since, just as Meeko described. After about a week of occasional driving, the car now starts straight up from cold instantly every time, barely even has to turn over now, and no hesitation at all (apart from when the TC kicks in
) and pulls strongly throughout the rev range, noticeably much better than before, really flies. I spoke to Phil at CPC not long ago as my car was in for the brake change, he mentioned that electrical connectors in general on BMW's are quite poor and he wouldn't be surprised at all if a connector to a critical DME sensor was causing issues.
So basically the car is now perfect just before summertime, so pretty happy chappy! Cheers to Meeko for the original idea earlier on in the thread, and I now have a spare MAF for sale if anyone is interested!
Andy
Using the technique described by I think 'Meeko' earlier in the thread, I got myself some Stabilant 22, quite expensive but turned out to be worth it!
I disconnected the MAF, used a load of contact cleaner on the MAF side and on the connector, let that dry out then added the Stabilant 22 solution to both the MAF male connectors and the female connector, then re-assembled. I noticed straight away the car pulled better with no hesitation, started better and it's got better every time I've used the car since, just as Meeko described. After about a week of occasional driving, the car now starts straight up from cold instantly every time, barely even has to turn over now, and no hesitation at all (apart from when the TC kicks in
) and pulls strongly throughout the rev range, noticeably much better than before, really flies. I spoke to Phil at CPC not long ago as my car was in for the brake change, he mentioned that electrical connectors in general on BMW's are quite poor and he wouldn't be surprised at all if a connector to a critical DME sensor was causing issues. So basically the car is now perfect just before summertime, so pretty happy chappy! Cheers to Meeko for the original idea earlier on in the thread, and I now have a spare MAF for sale if anyone is interested!
Andy
Sounds very positive. Is this the stuff? You're not kidding about it being expensive for the volume!
http://www.amazon.co.uk/Stabilant-5ml-Kit-Makes-30ml/dp/B001E50GQS
What size did you buy\need?
http://www.amazon.co.uk/Stabilant-22-N-A-0-5/dp/B00L37JRQ2/ref=pd_sim_sbs_ce_1?ie=UTF8&refRID=1G7KQYN8XCMR7B6ZYBTR
http://www.amazon.co.uk/Stabilant-5ml-Kit-Makes-30ml/dp/B001E50GQS
What size did you buy\need?
http://www.amazon.co.uk/Stabilant-22-N-A-0-5/dp/B00L37JRQ2/ref=pd_sim_sbs_ce_1?ie=UTF8&refRID=1G7KQYN8XCMR7B6ZYBTR
gwatson said:
The top link you put is the exact one I brought, shipped from Germany but had it in 3 days from ordering. Need some isopropyl alcohol 99% or above to mix with it but it makes loads of the stuff. Was a bit of a sceptic about it at first but without doubt this is most certainly the problem for the majority of people I imagine. A new MAF doesn't cut it by the way although I'm sure it wouldn't hurt, its the female connector where the problem is, at least for me anyway but I've no doubt this would also work for others as well. Bearing in mind I overhauled the VANOS, new ICV and a full clean of the whole intake side and this was the only thing that worked.
Stabiliant is used by BMW, VW and others if you google it so it's an 'approved' fix if you like.
gwatson said:
Yes instructions come with it plus a bottle to mix it in and the brushes, so all you need is the isopropyl.
Just to be clear, most of the hesitation I experienced was in the 3k revs and above range and a spluttery cold start up on occasions, both of which are now gone. If you have other issues including the rev dip, I think they could be an issue elsewhere and I don't know if this will fix it. But for me the main thing was the hesitation I experienced which is now gone
I'm happy to help anyone around london that suffers from the "rev dip" hesitation at idle speed, I solved the issue in mine. All it takes is 20min to access the Idle control valve, 20min to clean it (ultrasonic bath + carb cleaner) and another 20 to fit everything back again. (Plus two 25mm jubilee clips to replace the ones on the ICV connecting hoses, which are not reusable)
Cheers,
Gustavo
Cheers,
Gustavo