engine drops below idle??1.9 cdti 150

[rozzer2006]

hi guys, my 08 car drops below idle when i either coast or dip the clutch in. mabe between 10 and 0 mph when slowing down. has any body had this problem with their car or know what may be causing it? got the car cheacked with vx they said nuthin wrong with it they said it may be the erg? but the car runs totaly fine apart from this problem the cars only done 31000 and i use it every day. im totaly baffled

[Homer]

Does the engine actually stop or hesitate etc?

My old Astra's 1.7 used to dip to about 500rpm if I put the clutch in and coasted, but it recovered OK

[cont1204]

My Corsa used to do some of this when it had a MAF problem. I can't remember what the best thing to clean it with was off the top of my head but some form of 100% alcohol that will evaporate. Maybe nail polish remover? Sure someone on here will know.

[Ste]

I am not sure I fully understand what you are saying.

Are you saying that if you depress the clutch pedal (or knock into neutral) the engine revs go below what would normally be stationary idle? Or do you mean that if you watch the revs they stabilise at idle when you are moving and then drop to a lower idle speed when the vehicle stops?

"Driven idle" speed will be higher than stationary idle - perfectly normal and correct


Does the engine stumble or mis-fire or show any issues?

[mark_647]

Think what he means is, that when slowing down to stop, if you depress the clutch and coast to a halt, the enigne revs drop below idle, the engine slightly shudders untill the vehicle comes to a complete stop - where the engive revs increase to a normal idle.

Ive experienced this before in mine. Not sure what it is though, definately does not effect the drivability, just a weired one I think !

[john_k_sri]

The facelift 1.9CDTI has 'anti-stall' where the revs are held at the idle speed of about 800 rpm.

[rozzer2006]

hey guys thanks for ure input, Ste---"Are you saying that if you depress the clutch pedal (or knock into neutral) the engine revs go below what would normally be stationary idle? " ---this is it, like what mark 647 said the revs go back to normal when i stop, so iguess it is just a weird one :S. just want to get it sorted b4 the warranty finishes! the car dose do it alot but as i said no one found a problem and the car drives fine, i'm so baffled haha

[rozzer2006]

oh ment to ask whats a MAF? lol

[mark_647]

Mass air flow sensor mate..