Hello everyone!
I have a Mercury Cougar V6 2002, and its engine has been acting up lately.
Me and my brother have been trying to figure it out, but we're not quite sure what to think.
First of all, I thought my problem could be solved by changing the spark plugs, which I did. I found quite a lot of oil on some of them (not burnt residue, actual oil).
Because of that I thought that my problem could be coming from there; oil excess might have perturbed somehow the combustion. We think the problem is more electrical, I'd like to know what you guys think before we proceed to try and fix it.
The engine is running very irregularly, I have an intermittent problem. In idle, the engine sometimes stalls by itself. When it doesn't stall, I often get big RPM drops; most likely caused by missfires.
While driving, I often get missfires too. If I'm pressing on the gas when it happens, the engine starts right back up and the whole thing feels as if I tapped the brakes.
If I'm going downhill, not pressing the gas pedal, the engine doesn't start back up, but a little tap on the gas is enough to start it up again.
I don't have any coolant leak problem, the oil is of a normal color, although the engine does drink up oil.
We are not sure if the problem is in any way linked to that oil leak in the combustion chambers. I'm ok with an engine drinking up a bit of oil, I'm less OK with an engine stalling when it feels like it.
I do not own an OBD2 scanner, so I can't provide any diagnosis from that for now. I will manage to get one if necessary, but before that, I'd like to have you guys input.
Did any of you have/has heard of a similar situation?
Any of you have an idea what we should look into first?
I don't think it's linked to the fuel system. The pedal always answers perfectly.
Thanks in advance!