firewall
4 - 8
3 - 7
2 - 6
1 - 5
front
That would be an engine cylinder misfire , but either more than one or it can't determine which engine cylinder is misfiring
The number 5 engine cylinder is misfiring
For a 2002 Mercury Mountaineer : With engine oil filter change the 4.0 litre SOHC , V6 engine takes : ( 4.7 litres / 5.0 U.S. quarts of 5W-30 engine oil )
The P0300 code indicates random engine misfiring. The P0303 and P0304 codes indicate the cylinder #s where excessive misfiring is occuring.
1: Replace the injector. 2: If still misfiring, replace the engine.
most likely misfiring cylinder(s) and/or worn engine mounts.
On a 2002 Mercury Mountaineer : The 4.6 liter V8 engine uses ( 2 timing CHAINS / 1 CHAIN to each cylinder head )
Clogged injector, burnt valves, blown head gasket, bad intake gasket. spark plugs.
This means that your engine is misfiring on cylinder #3. It is either a bad sparkplug, wire or coil.
It could be (a) misfiring cylinder(s). Check the condition of your plugs and wires. Also, check if your engine mounts are not worn.
Number 2 cylinder is misfiring.
For a 2002 Mercury Mountaineer , 4.0 liter , SOHC , V6 engine : With engine oil filter change : ( 4.7 litres / 5.0 U.S. quarts of 5W-30 ) According to the Owner Guide