P0300 Service Engine Code, GM dealer repair before code, problems!
I sent my 2006 cobalt LS into the local chevy dealership about 2weeks ago because the timing chain broke. Of course when it broke it cleaned out the entire top end of the motor. They put new heads, valves, timing chain, tensioners, guides, etc. They fixed the car and called me to come pick it back up. Gave me 12 months or 12,000 miles warranty on everything and the reconditioned head has 2 years. I went to get it and the check engine light was on. Told them that it was kind of ridiculous that I just gave them almost $2400 and they return it to me with the check engine light on. It wasn't even on when I gave them the car. They hooked it up and read the code, said the O2 sensor was giving the problem. They cleared it and claimed that it was because they had the motor apart. Said it shouldn't come back on. Two days later, it's back. Took it back, code P0300, random misfire. They claim that there is nothing wrong with the car and they clear the code again. Pick it up later the same day. Fine, drive it home and park it for the night. Start it up this morning and immediately the check engine light is back on! I'm going to take it to someone else and let them use their code reader on it to make sure they are not lying to me about the code it is throwing and then I am taking it back again. Am I wrong to tell them that it is ridiculous that I just paid for them to fix the car and now they keep returning it with this issue? It has never had this problem before and I am afraid I am going to end up having to pay to have this fixed when it is not something that is my fault, it is something that occurred while they were fixing it. The car hesitates for several minutes and then runs normal after that whenever it turns the check engine light on. Any help/suggestions?
Code P0300 means random/multipule misfires
A code P0300 may mean that one or more of the following has happened: Faulty spark plugs or wires
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector(s)
Burned exhaust valve Faulty
Stuck/blocked EGR valve / passages
Faulty camshaft position sensor
Last edited by minihorse927; 05-22-2013 at 07:14 AM.