P0300 and other issues.
 

2000 V70 nonturbo
Getting P0300
Car runs a little ruff at idle, hesitates pretty bad at acceleration.
Have NGK plugs in at the moment, Will be getting EOM plugs soon. Used NGK for 5 years with no problems.
Iv checked the coils and they look fine. Wires look good. The wire wrap is pretty much gone on all wires.

Also having to add water/coolent every other day as it disappears. No water on the ground. Thinking it could be blown head gasket?
Would a blown head gasket give me the P0300?

Get a rotten egg smell sometimes also. catalytic converter?

Got to get this car running better as its a taxi for the wife and kids.

Please give me your suggestions.

Did you resolve this problem?

Hi and welcome to the forum.

I missed this thread, sad to see you are having issues.

Those could be 2 different issues, however, playing coolant roulette is not good. You need to find the coolant leak and get it fixed before you blow the motor.

The most common place for coolant to leak is under the drivers side carpet from a leaking heater core. You need to pull the carpet back and see if coolant is under there.

As for your misfire, you need to trouble shoot that and visually inspecting coils usually is not enough.

The smell is the converter. Check underneath front driver and passenger floor mates, if there is no water, then possibly the head gasket is leaking. Remove the cap on the coolant reservoir slowly (don't have it overfilled) and ask a helper to rev the engine, see if there's air bubbles inside the reservoir. You may also check each spark plug for color variation on the cylinder where is leaking.