Misfire in cylinder 4.

[HarryM]

They did extensive testing and determined that the exhaust valve on cylinder 4 was not seating correctly. Their recommndation was to just drive it as is. The vibration is just slightly noticeble at idle, so shouldn't be a big deal. He said at this time he would not recommend opening the engine up and reworking the heads, but if it gets worse, then I should pursue that. He said they were not able to do that kind of work. They did clean the throttle body about 1000 miles ago, so he it would't really be useful to do it again. He wasn't sure why the valve wasn't seating, but said it may be a stray piece of carbon. Who knows.

So, recommendations? Think it's safe to drive? Should I take it to a machine shop and have the head redone? I hate to give up on this expy, it's been such a great vehicle and I really love driving it.

Thanks

Harry

 

[1955moose]

Harry, just drive your vehicle for now. The thing that confused me, is in your first post, your mechanic stated that compression was good. When a valve is not sealing 100 percent, you'll usually have a compression loss on that cylinder. What's rattling around in my head is how your compression is OK on that suspect cylinder, and yet the valves leaking. The only time that could happen is if a valve spring breaks, and wedges the valve closed. It would be popping like crazy, if that was the case. Had that scenario years back, on friends girls Ford tempo. Fooled me due to compression OK on all 6 cylinders. Pulled valve cover, and #2 spring lying inside. I tend to think you have another issue, but for now, I guess just drive it.

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[HarryM]

Yea Moose, that confused me too. But the second garage with better mechanics and better diagnostics figured it out.

After having it for almost two weeks and spending untold hours on it, they are just charging me for the oil change they did. That's pretty nice.

 

[1955moose]

Boy I'll say! You don't find a shop that honest. Where are they located? I'm sure any of our members near your location, would enjoy their services. If you could post their business name for others. In this age of crooks, its nice to find an honest shop still around.

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[HarryM]

Moose, the shop is AAA Tire and Service at 3870 Kemp Rd, Beavercreek, OH 45431. I've gone to them a long time.

Unfortunately I got my Expedition back and it's shaking a lot harder. Almost undrivable. Looks like I'll have to look for different options :-(

 

[1955moose]

Sorry to hear that. Sounds like you've got a burnt valve, probably exaust valve, shame. Well, keep in touch, just have to put up with it for now. Moose.

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[Tdh777]

It will still build compression if it is not seating all the way, as long as it’s not open very much. A leak down test would need to be performed to be sure.

Harry, just drive your vehicle for now. The thing that confused me, is in your first post, your mechanic stated that compression was good. When a valve is not sealing 100 percent, you'll usually have a compression loss on that cylinder. What's rattling around in my head is how your compression is OK on that suspect cylinder, and yet the valves leaking. The only time that could happen is if a valve spring breaks, and wedges the valve closed. It would be popping like crazy, if that was the case. Had that scenario years back, on friends girls Ford tempo. Fooled me due to compression OK on all 6 cylinders. Pulled valve cover, and #2 spring lying inside. I tend to think you have another issue, but for now, I guess just drive it.

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[Adieu]

Coolant leak into #4

AND/OR

Messed up injector on #4

Swap injectors between #4 and a good cylinder and see if the code follows it... it's fairly fast and easy, and a replacement injector if you need it is a penny part for older Fords