Cadillac Catera and Cimarron Forum Discussion, 01 Catera getting P0300 code in Past Cadillac Vehicle Discussion; Hi,
My in-laws car had a P0300 code come up (random misfire detected). Where do I start? Could it be ...
That's the only code that showed up on my scanner. The car has new timing belt, water pump and serpentine belt. These were replaced early this year. I don't think there is any vibration, but will check and see what exactly is going on. I think it may be the valve coer gasket leaking oil and going into the plugs.
The car has about 135K and the plugs were changed early last year. I'm think it could be the coil pack or the plug wires, because once I started it the other the day, the car had a slight shake and when I accelerate it, the car would run fine and then it was okay. So far it is running fine, but will keep an eye.
Whenever I get this code, its because there is water in the sparkplug hole between the boot and the plug. It grounds out to the head giving you a random misfire. Sometimes I hose off the engine and forget to blow the water out of these areas.