Car shakes in and gear selection even neutral. Has anyone had this issue and fixed it? I've read that the harmonic balancer can go bad on these but this one looks good. Also, read the intake manifold seals can leak. Or could be the Idle air control. wanting to know what direction I should start going down first. Thanks
Go simple first. Seems your air fuel mixture may be off. Do smoke test and go from there
I agree with @bruceree. "Go simple first".
I'd add, check/replace the PCV valve and the PCV valve hose for leaks/deterioration.
If the engine only runs poorly at idle it sounds like a vacuum leak. You may want to watch some youtubes on guys spraying carb cleaner around vacuum hoses and the intake manifold to detect vacuum leaks.(Low tech/Cheap). A smoke test would be definitive. (but more expensive).
If the engine is shaking/running poorly at higher RPMs as well, it's probably not a vacuum leak.
In that case you could unplug each spark plug while idling, one by one, and see if you can find the "weak" cylinder.
(idle won't change)
Removing and examining each spark plug can also give you a hint to which cylinder(s) is causing the problem.
Frankly, on that 3.0 Ford V6 engine, I'd be chasing down ignition problems, (plugs, spark plug wires, coil pack) before any mechanical issues like an intake manifold vacuum leak or damaged harmonic balancer.
I had one of those that drove me crazy for a week because it was intermittent.
I waited until dusk, stole my wife's bottle of Windex, emptied it out and replaced it with water.
I sprayed the plug wires, from the coil pack to the spark plugs. In the "low light" I found a (now wet) plug wire arcing on a valve cover bolt. Replaced the plug wires and the problem was solved, for me.
(although my wife was perplexed over what happened to her bottle of Windex)
@jack62 I've found that the #5 cylinder has a misfire. Unplug the coil and no change in the idle. The coil is getting electricity even though the wiring harness shielding is cracked. I covered the cracks with liquid tape for a quick workaround until the new harness arrives. The coil does spark. swapped spark plugs from a known working cylinder. Still no dice. It doesn't shake at higher RPMs. I've eliminated the IAC as well. Any other leads I can chase while I wait for parts?
swap the #5 coil with one of the other coils. See if the misfire follows that coil
was just gonna add that in there but you beat me to it. swapped the coils still misfiring on 5
was just gonna add that in there but you beat me to it. swapped the coils still misfiring on 5
Also checked wiring harness is delivering 2 - 1.5 volts on #5. My next guess would be compression test or check the injector
The spark plugs did have oil on the outside. Read the valve cover seals are probably to blame for the oil
Isn't that a 2 wire COP coil? The red wire to the coil should be battery voltage (around 12 volts Key On).
The other wire is the Ground Switching Signal from the PCM.
You can test that with an LED Test Light.
Pull the fuel pump relay so the engine doesn't start.
Stick the Red lead of the LED test light in the Power terminal of the Coil's connector. (you just tested it and confirmed battery voltage)
Stick the Black lead of the LED test light into the Switching Signal terminal of the Coil's connector.
Have someone crank the engine and the LED test light should flash On and Off as the engine cranks if the computer is controlling the ground signal to the coil
correct 2 wires ok I will look into the ECM wiring and get back to ya
found cylinder 5 has low compression. Any leads as to what might be causing it for this engine? only has 101,000 miles
do a "wet" compression test. Put about a teaspoon of oil in the spark plug hole and repeat the compression test. If the compression comes up, it's rings.
If it doesn't come up, it's valves
Did a leak down terst. Found a bad exhaust valve any recommendation on places to get a new or used cylinder head?