Rough idle at cold start

[zman]

I noticed in the past few days with a cold temp outside my car has a rough idle.

When I am at the red light or make a stop, the rpm needle tends to drop below 500rpm, and the car responses with increasing the rpm. The rpm needle has been jumping up and down as high as 1500rpm. If the rpm needle idle, sometimes the mpg needle moves down to 25mpg.

does any one experience this?
Is this normal? or, is it something I should be concern about?[???1]

 

[dzervit]

I'd contact the dealer about it. There is a recall that describes your issue. Only way to be sure is contact the dealer.

Make : BMW Model : 325I Year : 2003
NHTSA CAMPAIGN ID Number : 03V124000 Recall Date : MAR 14, 2003
Component: VEHICLE SPEED CONTROL
Potential Number Of Units Affected : 1056

Summary:
ON CERTAIN PASSENGER AND SPORT WAGON VEHICLES WITH AUTOMATIC TRANSMISSIONS, WITH THE ENGINE RUNNING, AND THE VEHICLE AT REST, AN INCREASE OF ENGINE IDLE SPEED (UP TO 1,300 RPM) MAY OCCUR.

 

[zman]

At this time, thing seems to back to normal. I hope this doesn't come back again.

However, I notice that as when I am driving and making a stop, as the RPM needle is approaching idel and as soon as I press the clutch pedal, the MPG needle drops to 30MPG or lower.

This seems odd to me since a car should take less gas as you slowing down to an idle.

Do you all have experience this too?[???1]

 

[bahnstormer]

well it might be the recall it might be the cold weather. i know my car and most cars don't perform well nor do they idle well when the engine is cold.

the mpg needle works on a vacuum, don't be too concerned with it as you are stopping, so u're gettin 0 mpg anyway. =]

its just a neat gimmick that works when u are cruising, not braking

 

[sketch]

hey, glad someone mentioned these issues. i too have the wierd idle thing and the mpg thing too. i asked the dealership, and they said that the mpg thing was normal. the idle thing, they ended up re calibrating the gauges. since then it did it like twice but only after i gased up at shell . also my girlfriend said that the car died with the clutch all the way down plus another time in neutral coming to a stop because of the odd idle thing. hope someone has an answer.

 

[brahtw8]

There are a number of potential issues that could cause a rough idle during a cold start.

Most recently, I had to have the temperature control sensor replaced on my E36 when the car was having problems starting and hunting at idle.

Summer weight oil can also lead to problems with starting a car in winter.