View Full Version : Low RPM idle, then engine light turns on.. what could it be?
phomp
May 28th, 2009, 10:26 AM
Hey everyone, just a quick problem I have been trying to figure out.
Once in a while when I am idleing, the rpms shoot down to under 1000 rpm and then the yellow check engine light turns on. Nothing seems to be wrong once I am driving be the light stays on. Sometimes, it does not happen at all.
Also, when I fill up my car with gas, the light comes on and when I drive for a while it turns off. What should be checked here?
Cheers!
fastlayne
May 28th, 2009, 10:38 AM
You don't mention the make, model (and engine) or year of the vehicle, but I'd start by seeing what codes are being thrown.
Borrow a friends OBD2 reader and check for any trouble codes which will greatly help in zeroing in on what the cause could be.
belgiangenius
May 28th, 2009, 10:47 AM
This happened on my Civic awhile back and it was an oxygen sensor in the exhaust manifold.
The problem was not intermittent, though. It idled rough all the time, and the light stayed on.
KawaiiTentacleBeast
May 28th, 2009, 11:22 AM
Either the MAF sensor or the connection to the MAF sensor.
gherikill
May 28th, 2009, 11:26 AM
Partially clogged cat converter.
chadjustine
May 28th, 2009, 11:44 AM
EGR valve possibly?
fleabaggs
May 28th, 2009, 11:51 AM
I'm guessing MAF (Mass Air Flow Sensor)
Pull the code and see wht it is.
belgiangenius
May 28th, 2009, 12:08 PM
As many have suggested, the code reader will tell you which of the above it is. You can buy these fairly cheaply these days at Princess Auto.
m4gician
May 28th, 2009, 12:10 PM
Hey everyone, just a quick problem I have been trying to figure out.
Once in a while when I am idleing, the rpms shoot down to under 1000 rpm and then the yellow check engine light turns on. Nothing seems to be wrong once I am driving be the light stays on. Sometimes, it does not happen at all.
Also, when I fill up my car with gas, the light comes on and when I drive for a while it turns off. What should be checked here?
Cheers!
Does it jerk? It sounds like misfiring. Usually that's what happens when there is a misfire. If possible, you can check the spark plugs yourself.
phomp
May 28th, 2009, 12:27 PM
I'm starting to think it is the gas cap... I will check that real quick.