mis on # 6

[timmy]

I have a 02 ranger with a 3.0 and 120,000 hard miles that I use to tow and haul more weight than I should. It is showing a miss code on the # 6 cylinder. It had this problem before and it was do to a burnt and sucked exhaust valve. I replaced the head with a rebuilt one (from autozone I think) and that fixed it for the last 4 months. I have also replaced the plugs, wires, coil pack, fuel filter, fuel pump, and injector with in the last 7 months wile chasing this problem. I wont have a chance to run a compression test til this weekend, but assuming it is the valve again and not something like a fouled plug or burnt wire what would be the cause of the valve burning? Also any other thoughts on what it might be if its not a valve?Thanks for the help.

 

[bg@f.ord]

I have a 02 ranger with a 3.0 and 120,000 hard miles that I use to tow and haul more weight than I should. It is showing a miss code on the # 6 cylinder. It had this problem before and it was do to a burnt and sucked exhaust valve. I replaced the head with a rebuilt one (from autozone I think) and that fixed it for the last 4 months. I have also replaced the plugs, wires, coil pack, fuel filter, fuel pump, and injector with in the last 7 months wile chasing this problem. I wont have a chance to run a compression test til this weekend, but assuming it is the valve again and not something like a fouled plug or burnt wire what would be the cause of the valve burning? Also any other thoughts on what it might be if its not a valve?Thanks for the help.

I have a 02 ranger edge with a 3.0 and 120,000 miles.It had a burnt and sucked valve.I replaced both heads with a rebuilt ones. I have also replaced the plugs, wires & fuel pump within the last 7 months.My truck runs good for now.I hope for a while.Posts worry me about synchro.?? I hope it's not your other head.I had a bad plug wire cause a bad miss once.If ur lucky u need better wires.Also maybe bad lifter.Good luck

 

[timmy]

Thanks for the response. How do I check to see if my synchro is bad? I've noticed a squeal recently, could that be coming from the synchro? Also is this the same as a Crank Angle Sensor or camshaft position sensor? That seams to be what comes up when I search it. What brand / model plugs and wires do you all recommend? Its not the other head because Its on the same side as the new head and it is actually the same cylinder it was the first time around. Also It seams to run rougher when its cold and even out some when it worms up. Thanks again.

 

[Big Jim M]

Howdy Tim

Thanks for the response. How do I check to see if my synchro is bad? I've noticed a squeal recently, could that be coming from the synchro? Also is this the same as a Crank Angle Sensor or camshaft position sensor? That seams to be what comes up when I search it. What brand / model plugs and wires do you all recommend? Its not the other head because Its on the same side as the new head and it is actually the same cylinder it was the first time around. Also It seams to run rougher when its cold and even out some when it worms up. Thanks again.

Valves don;t burn all by themselves! They need a little help. The help comes in the form of too LEAN of a mixture being burnt in that one (or more) cylinder.

So with that in mind we have to look at HOW that one cylinder can get LEANER than the others..

Well first thing that comes to mind would be the INJECTOR for that one cylinder NOT placeing enough fuel at each spray. If that were to happen that ONE cylinder would be lots hotter than the others amd MIGHT burn a valve.

The other possible problem, and most common, would be a fresh air leak. This could be a vac leak at the intake runner to THAT cylinder. Also it could be an exhaust leak at that ONE cylinder. BTW this is the cause of most exhaust valve burns!

The plugs/wires have little to do with burnt valves. But since you asked... Stock wires and stock motorcraft plugs are far away the best you can put back into that engine. Wires themselves make little difference in engine running... They either work or they DON"T! PLUGS can be a real problem if the wrong ones are installed. So those that KNOW always use the factory plug in their engines.

Do that compression check and let us know. Hopefully all you need is a tuneup with the factory plugs and maybe wires too.
Big JIm

 

[timmy]

Thanks Jim it was an exhaust valve the first time but I can't find or hear an exhaust leak. Would an exhaust leak at the connection from the manifold to the pipe cause this or would it only be a blown gasket or crack in the manifold I'm looking for? I still haven't had a chance to run that compression test, but I'll let y'all know what it is. Like I said I replaced that injector already and when I replaced the head I replaced all the top end gaskets and torqued every thing to spec. out of my Haynes book. Also all the vacuum hoses looked good. A vacuum or cold air leak was my first thought also because it is worse when it's cold and gets better as it warms up, but I just can't find one. Are there any common places on these motors where I should be looking for one? Thanks again for the help guys.

 

[bg@f.ord]

Thanks for the response. How do I check to see if my synchro is bad? I've noticed a squeal recently, could that be coming from the synchro? Also is this the same as a Crank Angle Sensor or camshaft position sensor? That seams to be what comes up when I search it. What brand / model plugs and wires do you all recommend? Its not the other head because Its on the same side as the new head and it is actually the same cylinder it was the first time around. Also It seams to run rougher when its cold and even out some when it worms up. Thanks again.
How do I check to see if my synchro is bad? I've noticed a squeal recently, could that be coming from the synchro? .........................................................Yes.Remove serpentine belt.run engine for one minute.If it squeals probably synchro.http://www.therangerstation.com/tech_library/camshaft_position_sensor.html