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
Hi All,

Another update. Sort of. Had a call from the dealer today. Still not fixed. Instruction from BMW was to go "in-depth into the electrical side of things". Apparently it will still be days. So looks like they will have had the car for at least 3 weeks to a month trying to sort this.

In all seriousness, what happens if a car is under warranty, and can not be fixed?
 
Meeko said:
Hi all,

Yesterday I found time to clean my MAF connector. I have to say though it looked as clean as the day the car was built. Nonetheless, I used Deoxit as recommended to clean it (no dirt came off on the cloth). I also bent the contacts to ensure a better connection. It didn't make any difference at all. The revs still dropped when revving from idle (when warm), almost like a misfire. There is also still the flat spot up to around 2k RPM.

I didn't reset the DME adaptations as I suspect this is what actually makes the difference, not cleaning the connector, which is a red herring. Lets's hope that PSZ4Mc has some luck with BMW and we get to know the real cause!
Click to expand...

My "potential" solution is for the hesitation problem, which is what this thread was initially about, nothing to do with idle drops/etc. Sorry if this was not clear from my post.

Also, you did not really try what I recommended - i.e. clean and then use a contact enhancer.

I also did not have any luck with just using the cleaner or "bending" the contacts (male terminals is probably a better name). What did work with my original connector was twisting the male terminals on the "sensor" about 5 degrees - I also used the contact enhancer at the same time so not sure if twisting alone could have been enough (but I think so). My avatar pic clarifies what I mean by twisting, this would be the view when looking straight into the terminals of MAF sensor. If this picture helps anyone please feel free to upload somewhere and post a link, I haven't figured out how to do this yet and will probably not keep this avatar forever :-)

I am 100% sure that "my" hesitation/stumbling and loss of power problem was due to the bad MAF connector. I have conducted several experiments over months that proved this before I posted here. I have only reset the DME first few times, then I figured out it was not necessary - you get some immediate relief right away and then it gets better every trip till it comes back to full normal power in 3-4 trips.

Google "stabilant 22 MAF" and you'll find some good reading....

I'm guessing BMW will probably end up replacing electrical parts on your car one by one till they fix your problem.

Good luck.
 
Hi Masz4m, I cleaned the connector but I haven't purchased any contact enhancer yet, the problem has gone at the moment, how long do you reckon it will take before it comes back, if it comes back?

I will obviously then try the contact enhancer and twisting.

Cheers
 
stealthy21 said:
Hi Masz4m, I cleaned the connector but I haven't purchased any contact enhancer yet, the problem has gone at the moment, how long do you reckon it will take before it comes back, if it comes back?

I will obviously then try the contact enhancer and twisting.

Cheers
Click to expand...

The DME will usually 're-learn' the problem in a few hundred miles. If the problem is still there that is.
What would be great is if people with INPA or get INPA and post up results from their cars on values such as the Fuel Adaptations and VANOS readings, or anything that looks out of spec. I guess this might be a PITA for some people though :(
 
AndyBeech said:
stealthy21 said:
Hi Masz4m, I cleaned the connector but I haven't purchased any contact enhancer yet, the problem has gone at the moment, how long do you reckon it will take before it comes back, if it comes back?

I will obviously then try the contact enhancer and twisting.

Cheers
Click to expand...

The DME will usually 're-learn' the problem in a few hundred miles. If the problem is still there that is.
What would be great is if people with INPA or get INPA and post up results from their cars on values such as the Fuel Adaptations and VANOS readings, or anything that looks out of spec. I guess this might be a PITA for some people though :(
Click to expand...

I have INPA so can take a reading if you tell me exactly what you want to know :)
 
stealthy21 said:
AndyBeech said:
stealthy21 said:
Hi Masz4m, I cleaned the connector but I haven't purchased any contact enhancer yet, the problem has gone at the moment, how long do you reckon it will take before it comes back, if it comes back?

I will obviously then try the contact enhancer and twisting.

Cheers
Click to expand...

The DME will usually 're-learn' the problem in a few hundred miles. If the problem is still there that is.
What would be great is if people with INPA or get INPA and post up results from their cars on values such as the Fuel Adaptations and VANOS readings, or anything that looks out of spec. I guess this might be a PITA for some people though :(
Click to expand...

I have INPA so can take a reading if you tell me exactly what you want to know :)
Click to expand...

Awesome! Have you got any settings that are 'out of spec' as in, in the red?
Also a screenshot of the general sensor values, fuel adaption values, believe it's all on the same screen?
And also a VANOS settings screenshot? With the set points for inlet and exhaust side?
Hope that makes sense, I'll post up an example when I get a chance!
 
Hi All,

Another update.

Electrical side now checked. All is fine. But nothing cured.
Awaiting further instruction from BMW.......................
Getting bored of this now. :|
 
PASZ4Mc said:
Hi All,

Another update.

Electrical side now checked. All is fine. But nothing cured.
Awaiting further instruction from BMW.......................
Getting bored of this now. :|
Click to expand...


Join the club! :lol:
 
By acknowledging the problem exists, BMW have rather lumbered themselves with resolving the issue (unless they backtrack and try to claim it's a characteristic). I wonder if they realise quite the magnitude of the task they may have set themselves! Can anyone else envisage this scenario continuing until they eventually replace the engine? :?
 
stealthy21 said:
Hi Masz4m, I cleaned the connector but I haven't purchased any contact enhancer yet, the problem has gone at the moment, how long do you reckon it will take before it comes back, if it comes back?

I will obviously then try the contact enhancer and twisting.

Cheers
Click to expand...

I don't know how the DME relearns, but in my experience it seems to relearn in a few trips (3-4). My average trip is ~15 miles.

If the problem ever comes back for me I will definitely collect data and report back. But, I am pretty sure it is fixed now. I have been driving the car with new connector and stabilant for a few days (8+ trips), it is just perfect :-)

Few more things worth sharing:

- So far, I like stabilant better than the deoxit spray, can't speak for other forms of deoxit. Stabilant, once mixed with isopropyl alcohol is applied like eye drops, you put a couple drops (no idea how much is really needed but 2 seem enough) into each hole (or whatever it is called?) on the connector, then apply some on the terminals on the sensor using the brushes that are supplied with stabilant.

- I took apart the old connector, it is not like other connectors that you can crimp or tighten (at least I can't think how), it is quite delicate. Each wire from the harness goes into a silverish outer shell inside the connector and inside that shell is sort of an insert that has gold plated (?) contacts. So, the male terminals on the sensor go into this insert that then makes contact with the outer shell. I will try to get some pics some day. I think putting drops into the connector makes more sense then spraying since the drops can get between the outer shell and the insert.

- I wonder if there are other such connectors in the car that could benefit from the treatment. I checked a few (like TPS) but they seem to have the "normal" sort of connectors and not these fancy gold plated connectors with inserts and such.
 
The engine will run quite happily without the MAF connected and will revert to its base map rather than using learnt settings and input from the MAF.

For some people, this might be an improvement though fuel economy suffers.

When the DME was reset at my inspection 1 the symptoms vanished for approx 500 miles and then gradually reappeared over time.
 
If anyone with a Z4M that has INPA, if youve got the symptoms or not, it would be massively useful if you could take a screenshot of the below readouts on INPA:
2CF59857-6C85-4026-B92C-171BE8D65330.jpg
vanos.jpg

Post your results here and we can start comparing any differences between healthy and non healthy cars. Maybe there's an obvious pattern that isn't obvious when just comparing your own results!
 
Hi All,

Well after a month of tests and BMW looking at my car and replacing a multitude of parts, it's........fixed!

Apparently it was down to a faulty earth causing a voltage drop. Nothing more technical than that after all. I now have the car back and it's perfect. Happy days. And to give credit where credit is due. BMW stuck with it and sorted. I'm happy.

Cheers!
 
PASZ4Mc said:
Hi All,

Well after a month of tests and BMW looking at my car and replacing a multitude of parts, it's........fixed!

Apparently it was down to a faulty earth causing a voltage drop. Nothing more technical than that after all. I now have the car back and it's perfect. Happy days. And to give credit where credit is due. BMW stuck with it and sorted. I'm happy.

Cheers!
Click to expand...

Congratulations, basic fault but obviously a swine to find :thumbsup:

To help others check for similar problems any idea which component or earthing connection was bad ?
 
Hi PASZ4Mc,

Did you have any joy getting the report from BMW? If they aren't forthcoming, perhaps the technician who worked on the car coudl advise where the poor earth was?

It would be a great Christmas present for us all to know where to look!

Regards
 
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