1 series idling speed

[kenny c]

I have a 58reg 1 series 118d,the idling speed seems too high.When approaching lights or a junction I take my foot off the accelerator but the car carries on at almost the same speed,so I change down a gear and the car still surges forward.So I have to dip the clutch and brake,if the road is clear I release the clutch and the car still goes forward without my using the accelerator.When stationery the rev counter shows just over 8000rpm and it sounds too fast.This is my first BMW and I have been driving for over 53 years (motorbikes, cars and hgv trucks),but I have never experienced anything like this before. As a newbie, I would really appreciate some advice on cause and cure.I hope that I have posted this correctly..

[The Nur]

I really do hope you mean 800RPM

[thatdude]

What is the engine temp? I.e. is this during a short journey (engine still on a cold running cycle) or during a longer journey ( > 15 minutes)?

It could be indicative of:

-some sort of temp issue meaning the ecu is running on a cold-start map (thermostats are known for going a bit iffy)

-possible air-leak

See if you can find out what the engine idle speed should be when warm (a haynes manual, for example, might tell you)

[bomma220]

Welcome to PH! If it was my car, I'd look for a good local independent garage to help as without diagnostic equipment it may be very difficult to pinpoint the problem.
Try re-posting on the PH BMW forum, the guys on there may be able to point you in the right direction.
Good Luck!

[AJB]

doogz said:

800rpm doesn't sound excessive for a 4 pot diesel engine.

^This.

When it's accelerating on its own, what are the revs? If it's down near 800, then that's perfectly normal. The car knows it doesn't want the engine running below 800rpm, so will accelerate to try to keep the revs up. You just need to be in a lower gear whilst slowing, or press the clutch down.

If it's accelerating on its own whilst the revs are above say 1000rpm, then there's probably something wrong.