P0300 2006 Nissan Altima Sedan -w

Question

Ok my 2006 Nissan Altima service light is on and from time to time it
Blinks. I scanned it and the code came back p0300 multiple misfire, I replaced the plugs got new coils and still the same it runs really ruff a lot of shaking loss of power and hard too start. I started the car disconnected the coil wires one by one they all changed the way the car was running to rough to rougher except number 3 ..what could it be ??? Are the wires just bad to that harness ,, also my AC stop blowing cold air I charged it but it was full this all happened in a matter of a couple of weeks.HELP please..

Answer 1

HI there,

It's possible you have a bad head gasket issue on this. You need to check the coolant level, then pressure test the cooling system for one hour. Remove the #3 plug and look into the cylinder. If the head gasket is leaking usually there will be coolant pooled on the top of the piston. If the radiator is low, this will also cause problems with the air conditioning and make it blow warm.