Help me diagnose my engine problem!!!

[z71bam]

My 1996 Ford Explorer 4dr XLT with 4.0 OHC V6 is having an engine issue.

Whenever I start the engine, I feel abnormal shaking from the engine... as if one of the pistons is hesitating or sluggish.

Typically, I'll let the engine idle for about 10 seconds and it stops, but I once tried driving with the shaking and the *Check Engine* light came on.

I had the light checked and it returned [CODE P0303 3rd cylinder misfire]. I was told it's probably the plugs and/or wireset. The wireset is original and the plugs are 10 yrs old, so I had replaced them.

The explorer ran fine for about a month and now it's shaking again upon starting.

What do you guys/gals think the problem is and your recommendation? Thanks in advance.

 

[swetrid]

Pull spark plug and check to see if it getting coolant on it. Cracked heads are common on 4.0L OHV and usually start as cold start miss.

 

[z71bam]

Thank you for the response.

That 3rd spark plug is difficult to get to... before I spend money to go that route, I'd like to hear a few more potential fixes that I may be able to do at home.

 

[z71bam]

Pull spark plug and check to see if it getting coolant on it. Cracked heads are common on 4.0L OHV and usually start as cold start miss.

On second thought... this diagnosis may be spot on. I recall having an empty radiator fluid reservoir a few months ago. I replaced with more antifreeze and it seems level as of now.

What would be your recommended fix on this issue, Swetrid???