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
For anyone that's interested, BMMINI have the idle control valve priced at £190+ VAT and the inlet clips that you might break when removing the plenum at ~£3 each.

However, engine still seems to be running well so i don't intend to replace the valve unless it starts misbehaving again.

I wonder if there is any correlation between mileage and the problem starting. I bought my car with 13k miles on it at 3.5 years old so it hadn't had much use. It is possible that the valve gums up with low use.
 
For the first time ever in over 4 years of ownership mine displayed some of these symptoms tonight. It's an 07 car with just under 38k miles and does about 2-3k pa these days. I had a bouncing idle, really rough and it was running with a lot of hesitation/kangarooing from cold initially. However I had to stop only a mile in to my journey so whilst I was stationary I did a throttle reset and the car was fine from then onwards. I'll keep my eye on it though. At least this thread provides a useful body of reference for me to look at if it does reoccur. Thanks to all contributors so far :thumbsup:
 
Improvement hasn't been sustained :(

I've done approx 500 miles since i cleaned the valve and i think its now sticking again. The problem has not come back gradually, its come back suddenly. I'm going to disconnect the same electrical connections that i undid when i removed the valve on the off chance that that reset something, but i think the ultimate fault lies with the valve and the cleaning was a temporary fix.
 
I had similar results cleaning the ISV on another car-really frustrating after it seeming like a job well done :(

Still, and without wishing to jinx anything, perhaps replacement might be the permanent fix you're looking for :thumbsup:
 
Lower said:
Improvement hasn't been sustained :(

I've done approx 500 miles since i cleaned the valve and i think its now sticking again. The problem has not come back gradually, its come back suddenly. I'm going to disconnect the same electrical connections that i undid when i removed the valve on the off chance that that reset something, but i think the ultimate fault lies with the valve and the cleaning was a temporary fix.
Click to expand...

Shame but interesting.

My improvement has basically been sustained.

Today I felt it do it very, very slightly when I was bored and trying to get it to do it whilst in a traffic jam.

My test conditions were second or third gear slightly uphill on the overrun and when the revs get down to around 900 quickly half depressing the throttle.

There was a slight hesitation but it is sooo slight that only the driver would feel it if really looking for it like I was. Absolutely nothing like it was before, which was a disconcerting kangaroo where you felt for a second the thing was going to die and would then shunt forwards again - utterly horrible.

However, it did make me think pause for thought because when I cleaned everything out a few weeks ago, it did not do it at all.

So the thought crossed my mind today that it could be the start of a slow degradation process. . . . . . .

I will monitor mine. Let us know what you do with yours.

How about putting the ICV in a bowl of petrol for a while and then using brushes right into the throat of it either side to really clean it?

I wonder if it would be possible to "drive" the ICV between closed and open whilst off the car so it could be more effectively cleaned?
 
I'm inclined to think that cleaning the valve is akin to putting WD40 on a seized bearing. It'll run for a short time but its not a long term fix. Same with sticky brake callipers. Once they start sticking cleaning them isn't a permanent fix.

I presume that the valve is gummed up with oil and fuel deposits so unless it can be properly cleaned its only going to be a matter of time before it sticks again. I could strip it all down again and this time disconnect the hoses so that i could see inside the valve and make sure that its properly cleaned, but if it doesn't work its going to be a third strip down to replace the valve. I can't really be bothered to strip it a third time so i'm going to throw some cash at it and fit a new valve.

Ironically, the car was fine for a while again this morning. But its become intermittent and has good periods and bad periods within the same journey.
 
So it seems my Z has caught this disease :(

What is the general consensus for a fix/remedy? What items are best to check or replace firstly?

Going to have a read through this thread now but it is 10 pages long so thought I would ask before hand to perhaps save the reading to some extent :)

Thanks,

Chris
 
You could try cleaning your idle control valve as it's only just started happening for you. I'm 90% certain that it's the root cause of the problem. However I cleaned mine and the problem vanished. Unfortunately it's still an intermittent problem so I'm going go replace mine with new when I get a spare 2 hours.

Still much better than before though even with it intermittently sticking.
 
Lower said:
You could try cleaning your idle control valve as it's only just started happening for you. I'm 90% certain that it's the root cause of the problem. However I cleaned mine and the problem vanished. Unfortunately it's still an intermittent problem so I'm going go replace mine with new when I get a spare 2 hours.

Still much better than before though even with it intermittently sticking.
Click to expand...

Mine is still good, I can feel it a little bit on a rare occasion but nothing like it was.

Let us know how you get on with the ICV swap when you get round to it. :thumbsup:
 
Hi all,

My 07 Z4MR hesitates too and does stall sometime if you're not caredul. I had the DME software upgraded on mine in attempt to cure it but it made no difference. Is it worth paying my local Indy to clean the ICV? I don't want to spend anothe £150 or so if it's not the cause.

Also, from about 1500RPM the power comes in a surge - a bit like when a turbo spins up. Is this normal? I presume it's just theb VANOS changing the timing but could be wrong.

Cheers,

Steve
 
I still haven't got round to replacing the ICV. But since the initial improvement after cleaning its got substantially worse than it was before i cleaned it.

To my mind its clearly faulty and i've actually made the problem worse when the engine is cold by washing through solvent to clear out any muck. It is still slightly better when the engine is warm.

I still intend to replace the ICV, i just need to find the time to do it!
 
I also cleaned the ICV a few months ago, wasn't very dirty to begin with. Still slight improvement in the hesitation issue. Behaviour is quite constant after the cleaning session, not perfect but very acceptable. Previously I also replaced both TPS'es and still feel that they need a calibration of some sort however my garage says that this happens automatically...
 
Finally got to clean the ICV. And... it worked ! no more hesitation on throttle blip, and rev drop is largely improved (but not completely removed).
I've tried it all for this problem : reset the throttle (no improvement), replace both TPS (close to no improvement), have the valve clearance checked (no improvement). Finally, clean the ICV and all relevant hoses, big improvement.
I haven't made a lot of km since the cleaning, if it gets bad again, i'll keep you posted.
 
Shooter said:
Finally got to clean the ICV. And... it worked ! no more hesitation on throttle blip, and rev drop is largely improved (but not completely removed).
I've tried it all for this problem : reset the throttle (no improvement), replace both TPS (close to no improvement), have the valve clearance checked (no improvement). Finally, clean the ICV and all relevant hoses, big improvement.
I haven't made a lot of km since the cleaning, if it gets bad again, i'll keep you posted.
Click to expand...

Good news! :) From what I've read on the issue though O2 sensors seem to be a culprit as well so that would definitely be a port of call personally if it still didn't improve. Costly part though is the most annoying thing about that.
 
Has anyone tried to clean the ICV in a ultrasonic machine/bath?

I normally use mine to clean the carbs on my RS250. Works perfect!

For the record, mine is suffering form the blip throttle.
 
Anchefonk said:
Has anyone tried to clean the ICV in a ultrasonic machine/bath?

I normally use mine to clean the carbs on my RS250. Works perfect!

For the record, mine is suffering form the blip throttle.
Click to expand...

Not that I am aware of.

It could be a good way of cleaning it and resolving the issue.

My symptoms have started to re-appear, a few thousand miles since I cleaned the ICV by squirting carb cleaner down the pipes either side. The symptoms are bearable and not too bad yet, but are definitely on the way.

I may therefore take my ICV apart in order to give it a more "intensive" clean.

If that does not work, the solution may have to be a new ICV, which would indicate the ICV should perhaps be seen as a "consumable" item on the S54 powered Z4. :cry:
 
In october I'll work extensively in the car, got a long list to do.
I might dismantle the IDV and give it a little spa...
If it doesn't cure my idle problem, will look for a new one.
:fuelfire:
 
How's everyone's "fixes" doing? Still going strong or has it returned? Just bought my z4m last month and would like to get the problem sorted, I feel like I can't 100% enjoy the car till the hesitation goes away..
 
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