#3 Cylinder misfire code

have a 2006 Forerunner SR5 6 cylinder and check engine light came on, # 3 cylinder misfire. I replaced the ignition coil and spark plug on #3, started it up, ran fine, cleared the code, drove about 50 miles, all good. Next morning, check engine light comes on, same thing, so I took the coil back out, put it back in, cleared the code, ran fine. Not sure what is going on. Seems kind of random. If I clear the code it runs fine for a while.

 

While plugs and coil could be the most common could be a number of things.

Tried the plug wire?

 

Only replaced the coil and plug. Thought I had it fixed. Haven't had time to dig too far deeper. Will check wire as well as compression.

 

Bad head gasket

 

Just watched video on how coolant can leak into the cylinder and cause rough start, but then clears and runs ok when warm, and in my case, after I clear the code. Not really sure, just assuming that with a bad head gasket it is possible for coolant to get into cylinder, does that make sense?

 

Welcome.

Yes the head gasket will keep things where they should be. Even the smallest leak can seal when engine is warm and it expands with the heat. Just a sign to replace it before totally blown and engine damage.