A few months ago I started noticing a little vibration/shaking at idle in my 3.0 Edge automatic. This truck has around 122k miles on it and apart from this vibration the truck still runs great. I started looking for the source of the problem by scanning the truck but did not find any codes nor the check engine light was ever on. Tempeture, oil pressure are fine, I replaced the timing kit since the chain had already some slack and I was also hoping that could solve the problem but the vibration did not go away. On its next tune up I decided to put platinum spark plugs and cables and the Idle Air Control Valve (IAC) was also checked but was working properly so the source of the vibration is still a mistery.
I don't know if this is related to the cam synchronizer and positioning sensor as I read these units are good for 80-100k miles. I am hoping you guys can point me in the right direction on what to check next. Thank you.

 

So you have a misfire at idle but it goes away at higher RPMs?
And it is not related to motion of the vehicle?

FYI: either use regular Motorcraft spark plugs or use double platinum Motorcraft spark plugs.
Single platinum would be wasting money on Ford Waste Spark System.
Autolite is also an exceptable brand if Motorcraft is not available.

2004-2006 3.0l Rangers had a problem with recessed valve seats, this caused lower compression on the effected cylinders which would show up as misfires at idle first.
So a compression test wouldn't be out of line.

There were also a bad batch of coil packs in the early 2000's used on the 3.0l engines.
These would also cause misfires at idle.

But eventually both of these should get you a misfire code.

As far as just a vibration, check the fan clutch, usually this would cause the vibration at higher RPM first but.........grab the fan and see if it wobbles on the fan clutch, engine off of course :)

 

Thank you for your reply. I am not sure if I would call it a misfire but is a very slightly vibration, I never had any hesitation or stalling problems and even when cold the engine starts right up when i turn the key. I forgot to mention that I also had the e-fan conversion done recently so it no longer has a fan clutch and had a little improvement but the problem still there. Also the injectors have been recently cleaned up but I'll have to check on the coil packs as it wouldn't surprise me if that its the original set and based on what I've been researching so far i will need to check on this next:

Clean the MAF sensor
Replace the O2 sensor
Check Valves
CAM Synch & Crankshaft positioning sensor

I even read a case in this forum that recharging the a/c with 134a fixed someone's idle problem, apparently low ac preasure messes with the idle air control valve sensor even when the ac is off more so when it is on.

 

Thank you for your reply. I am not sure if I would call it a misfire but is a very slightly vibration, I never had any hesitation or stalling problems and even when cold the engine starts right up when i turn the key. I forgot to mention that I also had the e-fan conversion done recently so it no longer has a fan clutch and had a little improvement but the problem still there. Also the injectors have been recently cleaned up but I'll have to check on the coil packs as it wouldn't surprise me if that its the original set and based on what I've been researching so far i will need to check on this next:

Clean the MAF sensor
Replace the O2 sensor
Check Valves
CAM Synch & Crankshaft positioning sensor

I even read a case in this forum that recharging the a/c with 134a fixed someone's idle problem, apparently low ac preasure messes with the idle air control valve sensor even when the ac is off more so when it is on.

 

New to this forum, so bare with me. I have 2008 ranger FX4 shake at idle. Shake at all speeds just not as noticeable. Anyway just want you to know what the fix was. Started looking at motor mounts nope. Then put in new plugs, Still no change. Then wires, still no change. Coil pack, no change. Fan looked like out of round when spinning , So for test purposes removed belt started truck and shake was gone,run so smooth. Removed fan and clutch,found nut on clutch not centered. Go figure...only took about 6 months for me to find the problem. Hope this helps, All fixed, good feeling ! TY