I have a 2002 GMC Sonoma Highrider with approximately 144K miles on it. The vehicle is no longer my daily driver, as driven a few times a month for moderate distances. Last night the check engine light came on. I checked the usual suspects (gas cap) and nothing changed. I did notice the RPM at idle had dropped to about 500 from a normal 700. After a brief under hood inspection I noticed a significant amount of oil leaking from the top of the engine (I would describe it as around in the intake manifold, but this may not be 100% accurate). This was not a new leak. There is oil in the engine and oil pressure was not off. Are these connected to each other in any way and how would one go about fixing this?
For the check engine light, you need to take the truck to Autozone or some similar place and have the codes read. Post them here (P0123 or whatever) and we’ll go from there.
As for the oil leak, the location makes me think that the valve cover gaskets are leaking. Maybe one, maybe both, hard to say. They’re not difficult to replace.
Thanks for the feedback. I haven’t had a chance to get the codes read yet, but I’m going to get that done soon.
I’ll have to double check on the source of the leak. Head gaskets make more sense, but it just didn’t look like it was the source when I checked. I do know it is on the top of motor, and not below. Hopefully they aren’t too difficult. The newer engines w/ac have so much crap on top of them.
P0440 - EVAPOARATIVE EMISSION CONTROL SYSTEM