Ideas welcome P0300

Phaeton · Post by **Phaeton** » 29 Aug 2010, 23:15

I have an intermittent CEL code P0300, it tends to go away when it's warm out. I've taken it to the local Volvo shop 3 times. He can't find the reason for the cel. It's missing on cylinders 4&5. I've had new plugs,rotor,cap, wires, coil they all check out the right voltage.
I did a pcv job and tune up before this problem started, so I guessing it's something I did wrong.

Post by **Ozark Lee** » 30 Aug 2010, 13:58

It is a bit unusual to have a P0300 by itself. It is a multiple misfire code that is normally accompanied by the codes that identify the cylinders that are misfiring.

What kind of spark plugs are you using and did you gap them to 0.028?

...Lee

Phaeton · Post by **Phaeton** » 30 Aug 2010, 19:15

Yeah, it's got a multiple misfire code, I used oem volvo plugs. The mechanic checked them and said they where gapped perfectly.

Post by **Ozark Lee** » 31 Aug 2010, 04:34

Since you serviced the PCV just before the problem cropped up I think I would check the intake manifold gasket to make sure it is sealed.

...Lee