I purchased the truckused last year, and almost from the beginning it has had what feels like a misfire. I had the standard 60,000 mile service done - new plugs, flush injectors, etc, and still feels the same.

No codes displayed - and I just bought an Autoenginuity ScanTool to check it out. No misfire detected, though the O2 sensor signal looks a bit funky, but fuel trim is not out of line.

Am I nuts? I can FEEL the vibration at idle and through any RPM range. I'm not getting great mileage - like most of the posts around 14 in daily driving- short 7 mile commute. The dealer says they are not sure what they can do if it is not throwing a code. Any suggestions?

 

A buddy of mine at work has a '01 with the 4.7L and his "seems" to misfire at idle. Drives him nuts. Dealer cannot figure it out. He's had it in twice. The truck has done it since new, he said. They told him they see this problem on occasion and there's nothing wrong with the truck. However, the difference is that his only does it at idle, not through the RPM range like yours.

The only advice I can give you is to check your motor mounts.

 

know whats funny mine does this too...never thaught about fixing it...mabie i have a bad coil pak

 

Thanks - I'll check the mounts. One other thing - on a level surface, with the truck in drive and just enough brake to keep it barely rolling, I can feel shudder through the drivetrain - like a pulse at one half rpm frequency (cylinder firing frequency). That's why I'm thinking its a misfire and not a balance issue.

Anyone else got any ideas?

 

checked mine, no misfiring just has the feeling that it does, mine does that at a crawl too..