2013 Prius 4. I cleaned the intake manifold, and replaced the gasket. I replaced the EGR valve and tried to clean the cooler, cleaned the EGR pipe to the IM. Oil looks good, No smoke, No fluid loss. Still getting P0301. Changed the spark plugs. Error went away and then came back. Shutters a low speed... you know "that" sound. Any ideas other than a head gasket? TIA Justin
What’s the miles? try swapping the coil/plug on cyl one with four, see if the code follows. once the head gasket starts letting go, all the EGR cleaning won’t turn back the clock.
looks like I may be losing coolant afterall. I swapped the coil/plug on cyl one with four and the code went away, but there is a p0301 pending, so it's probably a blown head gasket. I used a borescope and looked at cylinder 1 and it was not steam cleaned. It had all carbon on it. it was all black.
Typical of a head gasket. They start slow and sometimes can be weeks or even months between rattles. But its kind of like cancer, you have a chance the save the patient if aggressive work is done early. Later it will be engine time, which it may need anyway at 253k if any oil leaks or burns. New rings are recommended if you wait for an engine. A rebuilt head even with a simpler gasket job. Give it one more cold start rattle. Just don't use chemo, it will clog up your arteries.
