Not idling well..

UK forum for general and technical discussion about the Z3 roadster
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chris1984_99_99
Joined: Sat 01 May, 2010 17:24
Posts: 200

  Z3 roadster 2.0
Location: Troon

Not idling well..

Post by chris1984_99_99 »

Hi guys.. its been a while since I was last on here... thats 8 years i've had the Z3 and she still makes me turn my head every time I walk away from her!

Unfortunately...shes starting to show her age a bit... but for over 125k miles and being my daily drive... I REALLY cannot complain! Recently however i've noticed every now and then..and now more and more often she seems to be idling roughly. I put it down to bad fuel and it used to be switching her off.. letting her sit then firing her up again solved it, but this is rarely the case now.

The last service I had all the spark plugs replaced. Looking through some threads on here it seems a fairly usual culprit is the ignition coils. Is that worth looking into or has anyone else had similar issues and of so what was the remedy? Basically she sounds rough, like not firing on all cylinders and there is excessive vibration.

Also in the last day or so the central locking has just stopped. The keys and batteries are fine. Would that maybe just be a fuse? Again if anyone has had this happen before?....

Thanks in advance guys! I hope you are all keeping well and still enjoying your Z's!!
Image

This sideways motion is feeling all too familiar...
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colb
Joined: Sat 05 May, 2012 22:46
Posts: 690

  Z3 roadster 1.8 TU
Location: Newport South Wales UK

Re: Not idling well..

Post by colb »

Since you have changed the plugs best to look elsewhere, might be an idea to check if any codes have been set before you start doing anything else, get a code reader on it.
What state are the plug leads in, at 125k they may be past their best by now letalone coils breaking down.
Would be worth checking all the rubber hoses on the intake side for split causing air leaks, replace any suspect rubbers.
Might also be an idea to flush out the idle control valve, they get gummed up and stick, wash out with carb cleaner.

What engine is in yours?

Bad idle and crap running on the move turned out to be a bad Maf on my M43 1.9 and that didn't set any codes. If you need new sensors or Maf do not buy pattern parts always go for oem brands Bosch or Seimens. You could try and find a good used Maf as they tend to be a tad expensive oem. Try disconnecting the electrical maf plug, the car should go to default settings, if things improve with it disconnected that points to a bad maf. Cleaning Mafs in my experience fails to fix them and kills tem completly.
Report back what you find when you check all these suggestions.
Colb
1999 BMW 1.8 Z3
2003 BMW 2.5 Z4
1998 Honda Deauville NT650V
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Gazza
Joined: Tue 04 Oct, 2005 20:58
Posts: 9521

  M roadster S54
Location: Romford Essex

Re: Not idling well..

Post by Gazza »

Coincidently my zed started running rough today with a misfire, I had this a few years ago and it was a coil pack.
Gazza

"Understeer is when you hit the wall with the front of the car, oversteer is when you hit the wall with the rear of the car. Horsepower is how fast you hit the wall and torque is how far you take the wall with you"

Z3 S54 M roadster Image, BMW Z1, BMW M3 CSL, Z4M Coupe
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Beemer Man
Joined: Wed 27 Apr, 2011 12:17
Posts: 80

  Z3 roadster 2.8
Location: Harrogate

Re: Not idling well..

Post by Beemer Man »

Two years ago my W-plate 2.8 required a new electric throttle body due to irregular running and loss of power. BMW-supplied at a cost of ~£524 plus fitting by my Independent, it transformed the car, which drove much more smoothly than at any time during the previous six years of ownership.

Beemer Man
Joycey
Joined: Mon 11 Jul, 2011 22:15
Posts: 290

  M roadster S52
Location: Basingstoke

Re: Not idling well..

Post by Joycey »

Start simple, clean the idle control valve under the manifold.
deni2s
Joined: Mon 25 Mar, 2013 22:02
Posts: 761

  Z3 roadster 2.8

Re: Not idling well..

Post by deni2s »

First thing to do is to read ECU error codes, that should narrow possible issues.
John Wilson
Joined: Fri 12 Jun, 2009 12:11
Posts: 252

  Z3 roadster 2.0
Location: Diss

Re: Not idling well..

Post by John Wilson »

I’m with Joycey here. The fact that it is rough idling only some of the time. Cleaning out the idle control valve costs nothing even though it’s a bit fiddley with getting the boots off and on down the inlet side. It’s a also good way to check the condition of the boots while you’re doing it.
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