I have a 2002 Ford f150. The engine in it is a 4.6 l V8 Triton XLT. I was told it has the motor from a Ford expedition in it.

AutoZone said when I get parts for it I have to look up parts for the expedition 4.6 l with a (W).

265,000 miles on it. New timing chain in 2017. I am experiencing a misfire on cylinder 2 and occasionally on cylinder 5. I have a check engine light come on that alerted me to something going on.

Shortly after the check engine light started to flash. I have replaced all spark plugs and all coils and still have the misfire. I took out the fuel injectors and cleaned them and put them back in and still a misfire. I even swapped out fuel injectors to different cylinders to see if anything changed but nothing did.

I suspected low compression so I checked it out and I do zero compression on cylinder 2 and low compression on cylinder one. I looked it down inside of the spark plug holes in I don't see any water but some of my spark plugs have oil on them.

Also I have really dark colored antifreeze but it is not sludgy. I do not have any milky or peanut butter look in my oil.

I recently had to change both valve cover gaskets that were leaking and I had a rear main seal that was leaking. A bottle of rear main sealer fixed that problem.

I have low oil compression when stopped at stop lights but the low oil pressure gauge goes back to normal when I hit the gas pedal or put it in park. I also have a bit of a loss of power when accelerating. Engine don't stall.no vacuum leaks I can find.

Sorry about the long post and all the extra things I added but I wanted to make sure everyone understood exactly all the problems just in case they were connected.

I don't know if it's just a bad head gasket or what. I do not overheat and as far as I remember this vehicle has never overheated. There is a very small amount of what looks like white smoke or maybe could be slightly blue. I can't really tell but it's coming out of the exhaust in the mornings but usually goes away after the car heats up. I can't afford to have the head gasket replaced.

My question is would head gasket sealer in a bottle fix a problem like this? Or should I try ring seal in a bottle since there is oil on spark plugs. Or both. Or am I going the wrong direction here. Please help!