We have a Winnebago Outlook 331C Class C with the 2006 Chevy Express 3500 chassis. On a 400 mile round trip over the past few days, we have been getting a check engine light. OBD scan indicates P0300, "Random / Multiple Cylinder Misfire Detected." We recently replaced all 8 the spark plug, plug wires, and ignition coils. The plugs were gapped correctly. This evening, I plan to check that all these connections are secure, to rule out something simple.
The "Check Engine" light seems to have started flashing just after we filled the gas tank.
This Post suggests that it might be bad gas, or gas with insufficient octane. The vehicle manual recommends a minimim of 87 octane, though some say that 89 is better. We therefore decided to alternate between 87 an 89.
We also had a brief incident where to coolant temperature gauge got into the red zone, but there were no other indication of overheating , such as smoke or steam. Slowing the vehcle speed remedied the problem quickly. Coolant level seems to be ok. Not sure of this could be related to the misfire code, but I though I would mention it.
Another anomaly: the check engine light appears to only light when the vehicle speed exceeds 65mph. It goes off at slower speeds. The OBD "Freeze Frame" indicates the fault occurred at 66mph / 2543rpm. Refer to the following pictures:
OBD Code 1OBD Code 2Freeze Frame Page 1Freeze Frame Page 2Freeze Frame Page 3Freeze Frame Page 4Any ideas?
Cartersville, Georgia
2007 Winnebago Outlook 31C Class C
(Chevy 6.0L 6000 Vortec Chassis)
