E30 Zone

My wife owns an H reg 316i Automatic. The same problem has persisted for years. On start up the engine hunts and blows blue smoke. I appreciate the vehicle is fuel injected but the only way I can describe the problem is with a carburrated vehicle the choke is left fully out. Before pulling away the vehicle has to be reved up but once the engine is warm the problem goes away. We used to send the vehicle to BMW for servicing and they were not successful in finding the problem. Does anyone have any ideas. Any advice will be much appreciated. Thanks.

have you tried changing the ICV (Idle Contol Valve)?

BTW: do you have one of these by any chance?

http://www.google.co.uk/imgres?imgurl=h ... CB8Q9QEwAA

This sounds like a common fault, my 318i has a similar problem, starts from cold, chugs away, will die if revs. aren't kept up. Once its been going for a couple of minutes, its fine, it doesn't seem to blow blue smoke though, I suspect the Blue sensor, but it probably needs a service.

We removed the ICV with the intention of replacing it. Unfortunately, we were supplied the wrong part. A mate of mine checked the old part and appeared ok. It was washed completely and refitted. The problem persisted but as the vehicle became warn the revs dropped, so appeared that it was working ok. The problem is especially noticeable in very cold conditions and much better in summer time. Do you think the problem is still the ICV? Thanks for your input, much appreciated.

Sorry what I meant to say was, the smoke is black not blue (blue being oil rings). It is, therefore, running rich at start up. Prior to this last service - very recent, the car used to hunt - very bad in winter but improved dramatically in the summer.

Thanks for the info about the blue sensor. Can you advise what it does and where I can find it?
Thanks.

if you test its resistance you should get around 3500ohms cold and 350ohms at running temp..it should be in the thermostat housing

Thank you, will look into it. will keep you updated.

leaking inlet manifold gaskets are common, try spraying the manifold ports with wd40 with the engine running, if the gaskets are leaking the engine idle will chance

Wish I could say that is the problem but gaskets are ok.

Thanks for the info about the blue sensor. It is now running sweet thanks to your input. Much appreciated.Problem solved.

Regards,

Nick

Hadn't noticed this thread before, and I see your initial description of the fault was spot on: " the only way I can describe the problem is with a carburrated vehicle the choke is left fully out". This is exactly the effect of a failed blue sensor.
Would you like to name and shame the BMW dealer who couldn't diagnose this most common and simple fault?

i have exactly same problem,changed the blue sensor to a new one,still the same

vokietis wrote:i have exactly same problem,changed the blue sensor to a new one,still the same

Valve cover and plug gaskets sound? ICV? Checked for other air leaks?