Rough idle and above on V6 Tribute (Escape)
#1
Rough idle and above on V6 Tribute (Escape)
I (wife’s car) have a 2003 Tribute (Escape) with V6. It has a shudder/rough idle and seems to skip and miss at idle and slightly above and the check engine light is illuminated. I do not own an OBD-II scanner (yet) so I had Autozone check the codes. Their generic code translated to engine mis-fire on cylinders 3 & 5. The AZ guys said its spark plugs, maybe coils? I installed new plugs & boots and while I had the coils exposed I checked the ohms of each and they fell within operating spec numbers that I found online. It still is acting the same. It seems to move prevalent when it’s raining out but will still shudder when dry. As I said it shudders and misses from idle to about 1500 RPM and then smoothes out. Any ideas to check? Other than getting my own OBD-II scanner I thought I’d check here for ideas. I am a “car guy” and usually do my own work but the Tribute has not needed any work until now so it’s a bit foreign to me. Before I begin to guess I thought I’d check here.
Thanks,
Thanks,
#2
I don't know about you, but if #3 was reported as misfiring, I would have moved it to the front head, in #6 for example, and maybe have moved #5 to #4. If the miss follows the coil, you have a hint...
That said, I have noticed that engines that have DOHC heads with the plugs 'down in a well' are much more prone to misfire by the coil or plug wire arcing to the head rather than across the spark plug gap than heads with the plug more exposed. I suspect that the dielectric material at the 'output' end of the coil or plug wires breaks down, especially when it has been immersed in motor oil after a seal failure filling the 'well' with oil.
I would do the coil swap, removing the intake manifold all over again, as a test. Likely you won't have to replace the gaskets if you replaced them recently. If you re-used the manifold gaskets, make sure that they have been 'rolled around' and 'exercised' a bit before you put them back in place. Sometimes you can revive the flexibility enough to get a good seal by doing that.
tom
That said, I have noticed that engines that have DOHC heads with the plugs 'down in a well' are much more prone to misfire by the coil or plug wire arcing to the head rather than across the spark plug gap than heads with the plug more exposed. I suspect that the dielectric material at the 'output' end of the coil or plug wires breaks down, especially when it has been immersed in motor oil after a seal failure filling the 'well' with oil.
I would do the coil swap, removing the intake manifold all over again, as a test. Likely you won't have to replace the gaskets if you replaced them recently. If you re-used the manifold gaskets, make sure that they have been 'rolled around' and 'exercised' a bit before you put them back in place. Sometimes you can revive the flexibility enough to get a good seal by doing that.
tom
#3
Detail
I guess I didn't go into enough detail. Shortly after my initial code reading from AZ I pulled the battery and reset the codes. After 4 days of driving and the check engine light came on I visited AZ again and the codes were a misfire in cylinders 1 & 6 so it did not coincide with the original reading. If it were a coil would it smooth out at higher RPM or jsut be more erratic. I never knew of a bad coil getting better as the RPM's increase? I may just buy a decent code reader and start over with my own readings unless someone here hits on another idea.
Thanks,
Thanks,
#4
#5
i have a 2003 escape, and had roughly the same issues which i ignored for some time. Mine was the number 5 coil pack. Some days it would rough idle and smooth out at higher RPMs, some days it would idle fine. Whenever it rained it would intensify greatly, and run rough no matter at idle or RPM level. After finally replacing my plugs and coil packs, it completely cleared up the problem.
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