Hey guys, took car to dealer after getting p0304 code at oreilly's and auto zone. Always good to make sure so i double checked. 10 minutes after dropped off car at dealer. Engine light wasn't even on upon drop off. Came and went the last few times upon starting. Was getting rough idle and sputtering when lightly accelerating. Came and went for a little over a week. Took it in and awaiting word expecting new plugs were needed. Haven't put new plugs In yet. 136,500 miles on it. Just had battery replaced under warranty a few weeks ago. Could this be a head gasket issue?
No, a head gasket issue would result in the engine overheating after a short while and the oil looking milky due to coolant contaminating it. p0304 means Cylinder 4 is misfiring, which could be the ignition coil pack for that cylinder, or the plug
I'm pretty sure mine didn't go to overheating when the head gasket issue was a thing. Also, the milky looking coolant is hard to spot. My head gasket was fucked up on 2 cylinders, and I couldn't even see any milky stuff from coolant, or the engine oil / cap. Posted via the PriusChat mobile app.
Not replacing the plugs at its interval change may contribute to head gasket leak and not just limited to that.
You mean spark plugs? Can you elaborate on how that affect the gasket? As far as I understand, head gasket issue is mainly caused because of overheating, or it simply just wear out specifically on Prius Gen III. Posted via the PriusChat mobile app.
