Engine Light and strange idle.

UK forum for general and technical discussion about the Z3 roadster
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dCatch
Joined: Thu 17 Nov, 2016 13:12
Posts: 12

  Z3 roadster 2.2i

Engine Light and strange idle.

Post by dCatch »

I have a 2002 2.2i M54B22 Z3 with around 85k on the clock.

Recently when starting the car the idle has been slightly strange sometimes at a higher rpm than usual and sometimes fine. It sometimes feels like the idle is rough with the car shaking up and down with the engine. The engine light comes on when the ignition is on but when the car is started it turns off.

I recently got a D900 OBM tool and it reads all the live data fine and pulls no error codes.

Any thoughts?
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lightning
Joined: Tue 27 Nov, 2007 08:15
Posts: 818

  Z3 roadster 3.0i
Location: Stockport

Re: Engine Light and strange idle.

Post by lightning »

When were the spark plugs last changed?
dCatch
Joined: Thu 17 Nov, 2016 13:12
Posts: 12

  Z3 roadster 2.2i

Re: Engine Light and strange idle.

Post by dCatch »

The car had a full inspection 2 service at 817400. Now on just over 85k. Not sure if inspection 2 includes spark plugs?

I bought the car at just under 84k. It has done about 5k in the last 5 years.

So maybe a full service with spark plugs would be a good idea.
Del
Joined: Sat 19 Nov, 2011 18:35
Posts: 2136

  Z3 roadster 1.9

Re: Engine Light and strange idle.

Post by Del »

Inspection 2 would normally include the spark plugs. Sounds like a vacuum leak to me - typically a leak would raise the idle speed and if the leak enlarges the other sensors would struggle to correct the situation. I believe on your car you have an upper and lower rubber bellows on the inlet side, either side of the MAF sensor. It is extremely common for one or both of these to split/perish with age on BMWs.
dCatch
Joined: Thu 17 Nov, 2016 13:12
Posts: 12

  Z3 roadster 2.2i

Re: Engine Light and strange idle.

Post by dCatch »

Thanks for the advice. I will give it a check over in the morning and see if I can find anything wrong with the lines.
John Wilson
Joined: Fri 12 Jun, 2009 12:11
Posts: 252

  Z3 roadster 2.0
Location: Diss

Re: Engine Light and strange idle.

Post by John Wilson »

Theres the idle control valve. It could need cleaning. Its not a bad job except for access to the jubillee clips around the boots. While the inlet side is off, also check that the butterfly is not sticking when closed. Search the forum for how to do it.
dCatch
Joined: Thu 17 Nov, 2016 13:12
Posts: 12

  Z3 roadster 2.2i

Re: Engine Light and strange idle.

Post by dCatch »

Just had a look around the bay.

Seems like the air intake boot after the MAF is perished.

See image:
20170408_105942o.jpg
I think that this is the part on realoem: http://www.realoem.com/bmw/enUS/part?id ... 3541705209

But the part that is perished doesn't seem to be on this part or any of the images I see on Google?

This one seems to be a better match: https://www.google.co.uk/search?q=air+i ... affhr6L_6M:

I am going to patch it as best I can with some tape for the time being and see if that helps.

Any other thoughts?
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Del
Joined: Sat 19 Nov, 2011 18:35
Posts: 2136

  Z3 roadster 1.9

Re: Engine Light and strange idle.

Post by Del »

Very common fault on Z3s which are now 14+ years old - new BMW rubber bellows are not particularly expensive
Does this diagram help with part numbers etc?

http://www.realoem.com/bmw/en/showparts ... Id=13_1747
therealdb1
Joined: Tue 25 Jun, 2013 21:47
Posts: 263

  Z3 roadster 2.0

Re: Engine Light and strange idle.

Post by therealdb1 »

Just contact a stealer with your chassis number.
For the rubber air hoses they do not live up to their name and the hoses are often cheaper and better quality than what you can get from fleabay.
Also if they supply the wrong part it's down to them to get you the right bits without you being out of pocket.
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