so my dads 97 has been giving us some problems latley. the check engine light came on with a PO0305 (cylinder 5 missfire) when the light comes on it starts to run really rough. we changed the plug and the coil pack, the plug had alot of carbon build up on it. after we changed them out it ran better but after 5-6 miles the light came back on and the missfire was back. this time it had 3 codes PO0305, PO0000, PO0000. i looked in my clymer manual and it has no code listed for the PO0000. also i dont kno if its related but the coolant keeps blowing out of the resivoir but its not over filled or overheating, any ideas? and thanks in advance

 

How many miles are on it? Sounds like you might have a head gasket failure and if the engine is very high miles you might just want to replace it with a fresher one.

 

well the engine has 140000 miles, i did a compression test on that one cylinder because we had the plug out and it had 160psi, later im going to do a test on all 8 to get a real reading, do you have any other ideas of what i can test???

 

Take it to a shop and have them test the coolant for exhaust gasses.