I have a 2002 cavalier 2.2L which has developed a unique problem over a year ago.
First, no codes are being set and engine runs well.
It has a random knock that sounds like pre ignition, at idle. When it occurs it makes 1-2 knocks every 3-4 seconds.
Map at idle is around 10.5 and varies with acceleration, but at 2500rpm in neutral, map stays around 10.5. The only reading which seems high is load which is around 25% at idle in park. The problem is the AC compressor runs fine in park, but when it is put in drive while standing still, it may randomly cycle on and off about every 2-3 seconds and the load will increase 5-10% each time it cycles on. Pressure AC readings are normal so it is not an AC problem. It seems to be because the load % is too high. Any ideas will be appreciated.
Its not a rod knocking is it? Ecotec or OHV?
Thanks for reply. It is 2.2L OHV It is random and not in sync with the engine so I don’t think is is a rod, It sounds like dieseling when it occurs. The main problem is the high OBDii load reading which is causing the a AC compressor to shut down. I can not find why Load reading is so high. And yes I have replaced the MAP sensor.
does the oil light come on when fully hot at idle?
- Your not-so-local, untrained, uncertified, backyard mechanic. But my @!#$ runs
An OHV that sounds like a diesel sounds like a timing chain to me.
i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick
Oil pressure light does not come on at idle or any time. It is not a jumped timing chain since the engine runs well, no pinging under load and there is no lack of power. It has an odd condition of high OBDii load reading. I can not find why the load reading is so high. Thanks again
What the hell is ODBii load reading??
Engine load readings of 20-30% will be seen quite often on may cars, especially automatics. Your A/C system may actually be low even with "normal" readings.
Did you really need to post in multiple areas??
J M wrote:Oil pressure light does not come on at idle or any time. It is not a jumped timing chain since the engine runs well, no pinging under load and there is no lack of power. It has an odd condition of high OBDii load reading. I can not find why the load reading is so high. Thanks again
Seriously though. My OHV sounded like a diesel really bad, timing chain needed replaced. It never jumped or seemed to lose power, but the chain did need replaced.
If you're not having problems with pinging, missing or anything, and the engine seems to run perfectly fine, why worry about it and make a post?
i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick
The hardest part of working on a car is diagnosing a car online. So no one can really answer correctly to your problem. Maybe the AC compressor is going bad...?
could be the ac compressor i would remove the belt and see if the noise goes away just cause theres no load on the compressor it still spins its uually a growl but i would say remove the belt that will tell you if its a belt driven issue if its still there i say timiing chain and tentioner
JBO since July 30, 2001
