BMW 318i cold performance

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Thu 11 May 2006 01:38
BMW 318i cold performance - debugslife
Hi

I got rid of the old Laguna and got myself a shiny E46 BMW 318i SE. I am really pleased with it but it has one strange habit. It starts great, pulls when stone cold like a tug but when the temperature gauge hits the top of the blue mark the car acts like the accelerator pedal is disconnected. It does not respond at all for a few seconds and then goes immediately back to normal, driving perfectly right up to when normal driving temperature is reached. I have been caught out a few times pulling out of slow junctions to find that I am trickling along at 5mph with a bus in my rear view mirror approaching rapidly. Luckily the seats have been scotchguarded.

It is in the BMW dealers being looked at under warranty but I have the feeling that (after telling 4 people my story and e-mailing them so that it was readable only to find the mechanic telling me that "that's not what I was told on my sheet") unless a diagnostic tool reads out a code that they can look up, they haven't a clue where to start. Closest guess when road testing it with a mechanic (alright vehicle technician) was that it may be the air-mass flow sensor.

Any of you guys seen this before? Any ideas would be appreciated.
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Thu 11 May 2006 10:45
BMW 318i cold performance - Aprilia
The MAF sensor doesn't 'know' the engine temperature - whereas your problem seems to occur at a very specific engine temperature. Obviously they will need to pull the codes, but I would start with the CTS.
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Thu 11 May 2006 23:39
BMW 318i cold performance - debugslife
What's the CTS? I actually got the car back today and they said that after driving the car again from stone cold they did indeed encounter the problem. They stuck it on some machine and started checking things (this is almost a direct quote from the service advisor chick) and they found that the chassis number wasn't being picked up by the VTC. They reprogrammed it all and said it was all smashing now. On my journey to work today the car seems to behaving perfectly. It also idles about 750rpm which is a lot better than before which was about 600rpm. I am sure that was not right. I will find out in the morning if the cold running behaviour is still there or not but at least the flatspots are gone and it is driving with the performance I was hoping for.

There you go 2 new acronyms that I don't know, CTS and VTC. Any clues?

Thanks for your reply.
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Fri 12 May 2006 00:49
BMW 318i cold performance - Aprilia
CTS is coolant temp sensor.
VTC is presumably for Valve Timing Control (BMW Valvetronic).
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