My wife's excursion has a rough idle. Not too bad but you can definitely feel it shake the vehicle. It was random at first but now seems to be all the time. Doesn't matter if the engine is warmed up or first start of the morning. I'll compare it to an old gas vehicle that needs the timing adjusted or the distributor rotated to even out the idle to make it smooth. I'm running 5-40 synthetic. No mods other than DIY 6637 intake. Could it be a cps going bad? It starts right up in the morning every time. No other issues other than a slight drop in mpg. Was getting around 17.5, now it's around 15.8 mixed city/highway.

 

Any CEL on? Im leaning towards a loose UVCH, It could be time for the 50 cent mod. usually the connector wiggles loose under the valve cover causing a wide range of issues. Search "50 cent mod". Also how many miles on the truck?

 

The excursion has 238k on the clock. No cel or codes.

I'll check the uvch.

 

Sure try the uvch's... free to check them save for a little time...

The connector on the inside of the valve cover likes to wiggle its way out of its socket in the valve cover gasket...

Search 50 cent mod.

If you can get access to a scanning system... i would run cct and rotational velocity tests.

Tom im going out of town today but should be back tomorrow if you are concerned enough about it you are welcome to scoot down here to Vic and i can plug in with AE. Like a 2 hr drive from magnolia... str8 down 59.

 

I hate to say this to you, but I just had a vision in my crystal ball... and I took a snapshot with my cell phone.