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
Wonder if it's similar to this stuff Z4M-2006 was on about the other week.

http://www.ebay.co.uk/itm/ACF-50-ANTI-CORROSION-SCOOTER-SPRAY-PROTECTION-ACF50-/400593415495?pt=UK_Motorcycle_Parts_13&hash=item5d453a6d47
 
srhutch said:
Wonder if it's similar to this stuff Z4M-2006 was on about the other week.

http://www.ebay.co.uk/itm/ACF-50-ANTI-CORROSION-SCOOTER-SPRAY-PROTECTION-ACF50-/400593415495?pt=UK_Motorcycle_Parts_13&hash=item5d453a6d47

Not quite, Stabilant is a contact enhancer and I believe one of the only of its kind. I believe the problem is the contact between the male and female pins can widen over time, I would imagine more so as the MAF is connected / disconnected with servicing and maintenance. Stabilant basically bridges that gap and provides better contact, in liquid form. That's how I understand it anyway.

Regards ICV cleaning it certainly can't hurt and would be a good first stop measure but having had a brand new unit I believe for some the problem can lie elsewhere.
 
Having nothing better to do this afternoon I popped the bonnet to try and see if I could cure this hesitation problem.

My symptoms are:-

The idle dip when blipping the throttle. Idle normally runs at around 800 and when blipped drops to about 600 before climbing back to 800. Interestingly though, before the initial first blip the idle remains unchanged at 1000 rpm. When blipping it seems lumpy and lethargic unless you blip harder where it does become responsive.

The normal kangarooing when dropping into second to either race something, drift round the roundabout etc etc

When stationary, blipping the throttle between 1000 and 2000 rpm it seems to misfire, hesitate etc and get the occasional popping between blipping. When over 2000 rpm it's as sweet as a nut 'race ready'

When in fifth or sixth gear at about 20-25mph, when you put your foot down slightly it drags before jumping forward.

I checked the MAF and noticed the terminals were all differently spaced so I closed the gaps and sprayed with a contact enhancer but no joy. I did the same with every connection I could find under the bonnet - but no Joy.

I disconnected the battery and thought I would look for earth cables. I found one on the offside under the manifold although not sure what it was for I disconnected the side I could reach and cleaned up, there looked like another connection on the bulkhead on the passenger side so I did the same with this one.

I reconnected the battery but the fault was still there although not as bad.

I sprayed WDF on the throttle linkages and then noticed that if you try to blip the throttle by just pushing down on the knuckle in the centre of the throttle bar it doesn't Rev but just hesitates- could this be a clue.

Frustrated at this point I though I would go for a quick spin to see if there were any improvements. I turned everything electrical off that I could and tried the high gear low Rev thing and thought it had improved but sadly not.

On the return journey I kept the revs high and it just made me smile, these cars are truly amazing driving machines with shattering performance - 5 secs to 60, rear wheel drive and two seats no doubt about it definitely a future classic.

Hopefully we will find this hesitation problem as it is the only flaw on these cars.
 
So ive had my M for 2 weeks now and this morning from cold the engine hesitated and felt like it was misfiring a little, it was fine when warm.

Is this the same symptoms as you guys have had on here? or is something else wrong that i should be taking it to an Indy to get checked?

I'm going to try a throttle reset later today and keep an eye on it. From what i've read - having the TPS? changed seems to clear this issue.
 
Well bond is practically ready to be retired so good to see you've bought a suitable vehicle :poke:
I had the issue when I got my car, it was fixed when the engine was rebuilt with new cams. None of the sensors were changed or touched, nor was the air intake system or maf wiring touched. Mysterious, but glad it's gone as it was bloody annoying.
In regards to the nickz4's post, that doesn't sound to me like the same issue. Typical scenario when you might notice the symptom would be pulling off out of a junction or some such, revs will die briefly.

jamesbond said:
Hi

This issue still going on .. I thought this would have been sorted now by some one ?


Anyway I am glad to say I have solved this problem with a 100% cure ...... wait for it .... I purchased a 35is ... :rofl: :poke: :fuelfire:

But seriously I had this on my 2007 Z4M .. never got to the bottom of it ? but my other 2 where fine and my Z3M S54 (2003 reg) was all ok as well, would be good to have a 100% systemic fix for this well known issue ..
 
I think all this thread has highlighted is that there is no single fix, which I've said before. There's no way it can be.

For example, Tom, you say that your issue was fixed when the cam's were replaced and engine rebuilt, to what extent of 'rebuilt' that means I don't know but maybe your shimming needed doing previously, or your timing was slightly out, was the VANOS re-adjusted? All those could cause the issues people are experiencing. Conversely, I've had a full VANOS rebuild using Beisan stuff, cam timing checked TWICE to make sure it's spot on, which it was, shimming done and cam's inspected for wear all of which were absolutely fine and I still had some of the issues.

These are extremely complex and sensitive engines, using lots of different inputs from many different sensors to calculate idle, throttle position and mixture control, and one of these being even slightly off could make the engine run differently. We have a much more complex and sensitive DME unit compared to the M3 as well which probably doesn't help. When an issue like this is highlighted we become hyper sensitive to it. Every garage I've spoken to, even high profile Indy's have mentioned the rev dip as being not something to worry about, which in the grand scheme of things, it makes little odds unless its actually stalling. It just becomes more annoying to us as we know it's there. That hasn't stopped me wanting to fix it though!

I suspect a lot of people could solve some of these issues by taking apart the intake side of the engine and giving everything a bloody good clean. The ICV does get very dirty after a while and even a very slight sticking of the valve would affect the idle momentarily. Eliminate the easy stuff first is what I'm saying before spending more money on expensive sensors. Taking apart the intake sounds daunting at first but I have no doubt the majority of us being car enthusiasts it should be well within most people's grasp to do, just put a day aside to do it and you'll save yourself a lot of dough and know that if cleaning the easy bits up doesn't solve it you can definitely eliminate it as the problem. Get a garage to do it and they may just spray a bit of carb cleaner down the hoses which isn't really the same as getting a cotton bud in the ICV and doing it properly if you see what I mean.

I'll do a separate thread next week on a few other 'easy' fixes that I've done recently that may help people's issues. The MAF connector for example, after speaking to an auto electrician, is a totally serviceable part and after watching him do it, it's very straightforward to clean the connectors and push the connectors back together. Basically what happens is the connectors push apart from each other over time making the connection to the MAF less solid. What they should look like is pinched together at the ends (inverted) so they have a firm grasp on the male MAF pins. Over time these connections will widen, especially so if the MAF connector is on and off a lot. This is NOT the same as pushing the connections together while it's still in it's plastic holder, this is not the best method. You can actually easily take each pin out of the holder and do it proper, 5 min job.

A chap (Meeko I believe) posted earlier on this thread about 'bending' the pins on the MAF itself, to try and make a 'better' connection. This is totally not necessary and I wouldn't recommend doing it, as my auto electrician guy mentioned, it's a 'bodge' and will work for a while, but all it will do is end up pushing the actual MAF connectors further apart so you end up with an even worse connection eventually.
I've concentrated on the MAF a bit there, but again it's an absolute integral part of the breathing of our engines and if it's giving even a slightly wrong reading while stationary or at speed or wherever, it will throw the engine totally out, perhaps even causing the hesitation some of us experience. It pay's to make sure this is working correctly first before going further in depth replacing other parts. A good method, although not fool proof, and it's been mentioned many times before is disconnect the MAF and go for a drive. The car won't feel perfect by any means, but you should be able to feel if your still getting similar hesitation issues or not and or an idle dip. If both these problems are improved/solved with a disconnected MAF, you can be pretty certain something is up with either the MAF or the airflow to the engine in the intake area.
Those of us with aftermarket intakes having issues, it's worth putting your standard airbox back on and seeing if that fixes the issue as again this can affect the smoothness of the engine, BMW actually released a service bulletin relating to our engines and this issue stating intakes can affect the normal operation.

Another thing to look for, any pipes relating to the intake side of the engine. Splits, cracks, perished hoses, hoses that should be round and not flat! I solved my idle drop with the simplest of fixes that I missed for ages. One of the smallest hoses which connects to the brake booster lines/vacuum lines at the back of the engine, it's an elbow shaped hose, had flattened if you like, don't know how or why, just perished over time I guess. Ordered a new one from BMW, nice round hose as it should be, fitted it and boom, idle solid as a rock. A £3 hose! Also had the affect of firming up the brake pedal as not enough air was getting to the master cylinder and instead just going back to the engine. If you look at the brake vacuum pipes, you have a sucking air pump and an air return valve coming off the intake elbow. The sucking air pump leads straight to the alloy air control bar at the top of the engine. As you can imagine, too little or too much air than expected up here and your idle's going to be off, as in my case. The engine will effectively choke, causing the rev's to dip slightly before the engine can adjust the fuel it's putting in to compensate, hence the rev's jumping back up.
I noticed my issue was much better before I cleared the adaptions set by the DME. This is because over time the DME will automatically (learn to) add or subtract the amount of fuel at certain throttle/load adjustments (more complicated than that but basics) to compensate for whatever the issue is. If you have the benefit of INPA or DIS, you can see what the DME has learnt in this respect, the 'multiplicative' fuel adjustments. This can help massively with diagnosing issues. If for example you have a minus 'learnt' fuel adjustment, the engine believes it's not going to ever get the air it expects and will automatically cut the fuel in for the less air it's getting, masking the problem to a degree if you like but in return potentially leaving performance on the table.
Basically, if you have a 'minus' value multiplicative learnt, it could mean the air measured at the MAF is consistently getting out somewhere after the MAF and the engine is now putting less fuel in to compensate for that air disappearing. I've been told by an expert on these engine's that more than a couple of percent adjustment could indicate a vacuum leak in this instance.
A 'plus' value means the engine is getting more air than it expects after it's measured by the MAF, and put's more fuel in....you get the idea! Either way, it can affect the overall running of the engine slightly but more importantly it can help to tell you where a problem might lie. In my case, I could eventually see that my engine was adding more fuel to mix when dropping from rev to idle, I can only assume that this was because of the flattened hose pipe to the brake system which was not getting air fully to the master cylinder and going back into the engine unexpectedly, causing the rev dip.
I stupidly when I first got INPA deleted all my adaptions hoping that magically it may solve the issue. It doesn't, it just delete's the useful adaptation information that have been gained over time and reset's it all to zero, making the car learn again. If you know you've fixed a problem and your engine is sweet as a nut, then great, it'll probably make it run better as it'll relearn it's fuelling adjustments. If not, you just delete useful info, and these DME's take some time to relearn apparently. It doesn't happen in a few runs put it that way.

I've lost my train of thought slightly so I'll leave at that for now, basically I've done a hell of a lot of research into this issue, consulted many different specialist indy's and studied the live data on INPA and DIS thoroughly to try and see what the engine's actually doing. It's kind of interesting actually if your a bit of a geek like me, but it's still incredibly difficult to diagnose issues, especially when you don't get EML lights telling you exactly what the problem is, and many of us don't.

Basically, my advice would be, eliminate the easy (cheap) stuff do first, cleaning bits up (moving parts), throttle bodies, ICV's, that kind of thing. Check ALL hoses on the intake/vacuum side, including all lines leading to the brake master cylinder as these all form the 'vacuum' in the engine and any irregularities even small one's could affect the idle and potential hesitation issues. Then go from there, as when you start replacing sensors and other parts, the bill's will mount up pretty quick believe me! The VANOS can affect all aspects of the running of the engine, if it's leaking slightly, a perished seal, can all lead to a bad idle, hesitation/power issues. The list can go on and on, just depends how badly you want to fix it I guess! :)
 
I recenetly developed a misfire on cylinder three during a track day. I changed the plugs and the misfire cleared.....and the engine ran with much more enthusiasm than it has in maybe six months. This made me realise that I was insidiously developing the dreaded hesitation problem and driving round it without giving it conscious thought. For those of you with hesitation or an engine that just doesn't seem quite as keen to rev as it should, include changing the plugs on your list of 'Basic things to do before throwing money at it'.
 
My car has just had its inspection 2 so plugs were changed and the adaptions cleared. Nor error codes recorded and nothing out of tolerance in the diagnostics.

The flat spot below 2k rpm has gone again (probably due to the adaptions being reset). However, the rough running when cold hasn't changed.

I suspect the flat spot will gradually come back as whatever sensor is telling the DME to change the adaptions will still be outputing the same info.
 
I have just took the intake off and given the ICV a clean along with the throttle bodies etc.
It has helped with the idle dip and hesitation, however I must have caused another problem now..

Under full throttle at around 4-5k it seems as it my throttle actuator closes, giving a tremendous amount of hesitation.
I have purchased a used m3 one off the net, changed it along with changing the throttle sensor, still having the same problem.

I took it to the garage and they say it is the throttle actuator but BMW say the actuator is part of the throttle bodies so all need to be purchased at once, then a possible re-programme (total quote nearly £650) but I am reluctant to go down this route as a new actuator didn't fix the problem.....

Has anyone else here had the same sort of problem and did they get to the bottom of it?
 
What did BMW say needs changing all at once?

If you change the actuator you should do the throttle alignment as well. There is a guide on doing this but to be honest there's a few specialist tools you will need and it's quite fiddly so probably better off letting BMW do it. Can't remember if there's anything in DIS that needs doing on top of that but don't think there is.

As for your actual problem, are you using BMW hose claimps for the intake manifold to throttle body connection or jubilee clips? Anything else none standard? Sounds like the throttle bodies aren't opening fully which could be a number of things, but check the basics first such as making sure they have total free movement. Have you changed the TPS sensor on the throttle bodies as well? If you put a wrench on the end of the actuator you can gently check its movement manually to see if it's sticky at all and if it's opening all the butterfly's correctly and fully, obviously you need the intake manifold off to do this.
 
They said I need all new throttle bodies aswell as the actuator (can only quote for the pair apparently).

Yes I have replaced the intake clips with jubilee clips, I've had it on and off a few times and check the actuator moved freely, I believe one of the jubilee clips may have been in the way to begin with but I have now moved it round.

I haven't tried aligning the throttle bodies as didn't realise I could have knocked the adjustment while cleaning them, they mentioned reprogramming which I wondered what they actually meant by this?

While I was there I fitted an eventuri intake, which I don't think was the problem as I put the oem box back on and the problem remained the same.

I am tempted to just have the alignment checked and just a 'reprogramme' as it can't be both actuators with the problem...

Let me know your thoughts :thumbsup:
 
darkpker88 said:
They said I need all new throttle bodies aswell as the actuator (can only quote for the pair apparently).

Yes I have replaced the intake clips with jubilee clips, I've had it on and off a few times and check the actuator moved freely, I believe one of the jubilee clips may have been in the way to begin with but I have now moved it round.

I haven't tried aligning the throttle bodies as didn't realise I could have knocked the adjustment while cleaning them, they mentioned reprogramming which I wondered what they actually meant by this?

While I was there I fitted an eventuri intake, which I don't think was the problem as I put the oem box back on and the problem remained the same.

I am tempted to just have the alignment checked and just a 'reprogramme' as it can't be both actuators with the problem...

Let me know your thoughts :thumbsup:

Erm, I think there's some confusion here, are you sure they said throttle bodies?? If so, that's shite, I've never heard of them being replaced ever, and why would they be, they're not a complex part as such that fails. I think what they mean is the throttle position sensor, the actuator comes with one all as one part, which actually is fine as if you've already replaced that one you can whip it off and replace the other TPS sensor on the throttle body arm. Just to clarify there is only one actuator, not two.

You wouldn't have disturbed the calibration of the throttle bodies and the actuator unless you went out your way to do so. If you install a new actuator it does need recalibration though, they might be referring to the software side of it in terms of reprogramming as you can check in ISTA that it's working correctly I imagine.
Sorry getting a bit confused here myself now!
 
Well I purchased an actuator which a had the sensor on the end, so would imagine that sensor to be fine.
The problem remained so I just swapped out the other sensor near the front with the one from the other actuator, trying to rule one of the 2 original sensor out..... however the problem remained.

They said it was the throttle bodies needed ordering aswell, hence the steep price for £500 for parts alone.
I nearly went ahead and let them buy the part and do the job, but had a feeling it wouldn't have fixed the problem.

I may just have to purchase 2 brand new sensors then get them to recalibrate the throttle, just seems weird they worked absolutely fine before I took the intake apart to clean....
 
darkpker88 said:
Well I purchased an actuator which a had the sensor on the end, so would imagine that sensor to be fine.
The problem remained so I just swapped out the other sensor near the front with the one from the other actuator, trying to rule one of the 2 original sensor out..... however the problem remained.

They said it was the throttle bodies needed ordering aswell, hence the steep price for £500 for parts alone.
I nearly went ahead and let them buy the part and do the job, but had a feeling it wouldn't have fixed the problem.

I may just have to purchase 2 brand new sensors then get them to recalibrate the throttle, just seems weird they worked absolutely fine before I took the intake apart to clean....

For the price of the sensors your best off just buying new and replace both, only way to really rule them out as an issue, if your near the Reading area I'll happily plug in diagnostics for you and take a look at what's going on if you like.

Ask them what part of the throttle bodies has failed and why they need replacing, they're talking rubbish!
 
Something doesn't add up here..
One throttle body is about 300,- (there are 6 and lots of add on components) so 500,- for the 'throttle bodies' would be a bargain.
 
Rene_Z4MC said:
Something doesn't add up here..
One throttle body is about 300,- (there are 6 and lots of add on components) so 500,- for the 'throttle bodies' would be a bargain.

Aye that's also true, even for that I still wouldn't get them replaced though. Can't see what would possibly go wrong with them!
 
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