Howdy,
I have a 2005 scion xb manual transmission vehicle with 174000 miles on it and just the other day i got a p0301 code and the car was idling and running super rough at low rpms, luckily enough i was close to a place i could park it for a bit to get it figured out.
First i assumed it was a spark plug, so i pulled the plugs and sure enough, the number 1 plug is covered in oil.
I was hoping it was just the gasket, could not see obvious signs of wear. purchased a new gasket anyhow.
looked at all of the pistons by eye through the spark plug tubes the first is moist with oil the other 3 are dry and black with carbon.
my question is where do i go next with this? i have limited tools, time, and money.
any advice will be more than appreciated, thank you in advance!
have a wonderful day.
If one plug is getting oil fouled (tip oil covered, not just the outside of the plug) you probably have worn or broken rings in that cylinder. Do a compression test.
Also do a leak down test to see if it might be a bad valve stem seal (hopefully not the piston rings).
