Missifire detected in cylinder 3,5,6

[OHMedic]

I have a '97 XLT 4.0L SOHC with 132k on it. Last night while driving began to run rough, started to backfire, sounded like a lawn mower, lost a lot of power. pulled the codes and I got P0303,P0305,P0306. I know those are missfire codes for cylinder 3,5 and 6 I am trying to figure out what would be causing this. it started to idle rough about 2 weeks ago, I thought it was a cheap gas thing at first but the warmer the engine got the rougher it idled, it ran ok at speeds just the idle was rough, then last night it got real bad. and real loud.

any help would be greatly apreciated.

 

[mcG]

i know bad spark plugs or plug wires can cause a misfire, but if it happened to 3 cylinders at the same time i'm not sure what it could be...good luck though, misfires suck

 

[OHMedic]

thanks, I am going to put a new coil,wires and plugs on it and hope that it does the trick..

 

[Eneurb]

I hate to say it, but it sounds like you may have timing chain problems.

 

[OHMedic]

welp I just dug into it, new coil, cleared codes fine, however found a broken off spark plug in cylinder 5. so now I know at least know why it got so damn loud. hopefully it just worked its way out, havent dug into anymore yet, dont have the space to take the tire off to get to the damn thing.looks like it didnt break into the block so hopefully am good there.

 

[Eneurb]

Well, if that's the case, I'm glad I can withdraw my previous statement.

 

[OHMedic]

well here is the bad news. I tried to retap the head for the spark plug, no go. looks like either a good machine shop or a new head. unless anyone out there has a better way to fix it.

 

[jimbo74]

why were you unable to retap the head?

 

[OHMedic]

tap just slid through it.