low/unstable RPM?
08-30-2008, 05:45 PM
#1
low/unstable RPM? This morning when I was going to pickup a friend before heading to work I noticed my RPM were acting a bit funny.
I was idling like at 400rpm (didn't realize it until I went to go backup and stalled the car, something I rarely ever do). Once I started up the car again I noticed my rpm idle was extremely low <500. My RPMs also dropped very quickly after letting go of the throttle making smooth shifts nearly impossible. When I reached my friends house I turned off the car, popped the hood and checked the air filter but it seemed fine. After I started it up again it was acting fine.
But, my RPM still seems to be erratic, the rpms are usually constant but occasionally you will spot them drop like 100rpm for like 1-2 seconds then jump back up to normal while at idle.
Don't know if this helps any, but my gas mileage is also very sucky and my car doesn't seem to be very smooth at idle( i've been told this may be normal) (like 150-160 a tank), and just replaced my front 02s.
Car is a '99 m6 with 45k miles pretty much bone stock except for the exhaust I installed. Don't know what was done to it maintanance as I just bought it.
I was idling like at 400rpm (didn't realize it until I went to go backup and stalled the car, something I rarely ever do). Once I started up the car again I noticed my rpm idle was extremely low <500. My RPMs also dropped very quickly after letting go of the throttle making smooth shifts nearly impossible. When I reached my friends house I turned off the car, popped the hood and checked the air filter but it seemed fine. After I started it up again it was acting fine.
But, my RPM still seems to be erratic, the rpms are usually constant but occasionally you will spot them drop like 100rpm for like 1-2 seconds then jump back up to normal while at idle.
Don't know if this helps any, but my gas mileage is also very sucky and my car doesn't seem to be very smooth at idle( i've been told this may be normal) (like 150-160 a tank), and just replaced my front 02s.
Car is a '99 m6 with 45k miles pretty much bone stock except for the exhaust I installed. Don't know what was done to it maintanance as I just bought it.
09-02-2008, 07:47 AM
#4
if nothing else is wrong, check your fuel filter.
i had that exact same problem where it would idle low and if i blip the gas the rpms would drop so low that the engine would stumble. it started off as once every blue moon, then then a few months ago it started happening every other start. replaced the fuel filter and never again.
i had that exact same problem where it would idle low and if i blip the gas the rpms would drop so low that the engine would stumble. it started off as once every blue moon, then then a few months ago it started happening every other start. replaced the fuel filter and never again.
