Maybe a long shot, but I had a similar rough idle shakes at stoplights many years ago. I realized there was a tiny pressure mist leak out of my radiator cap (bad seal) which creates a near overheat cycle. This causes the high speed fan to randomly kick on and off at stoplights and rumble the cabin due to the power draw. Now I regularly change the radiator cap every 2 years...cheap insurance.

 

I'm a man of this theory and it's funny you mention it because there is a brand new AC Delco cap on there but I can't remember if I did it before or after the issue started. I'll add this to the list since there was nothing wrong with the old one and try it and see if anything changes. Very easy to test and a good idea. Thank you.

 

I can't think of any time that a tech would have the throttle body off but anything is possible with these people. What's the throttle body tear down and install process?

Disconnect battery
remove 4 star screws/bolt (the thermostat housing is almost in the way of the lower right bolt. I only have this in a 3/8 drive so maybe I need a 1/4" set?
remove electrical connector
Clean throttle body and remove whatever that gasket thing is
Reinstall gasket? How does it fit on the pieces? Obvious?
plug in electical
tighten bolts
connect battery?

Getting ready to drive it 1400 miles next week. Could really use this problem fixed lol.

Thanks again Mr., T. I purchased the Fel Pro 61467 which says Alternate/OEM Part Number(s): 4666113AA, G32002

https://www.rockauto.com/en/moreinfo...41555&jsn=2178

It was the one I took a guess on but when the package arrived it says on it 3.7L SOHC Eng , 2006-07

What do you think? Is it this other one possibly?

https://www.rockauto.com/en/moreinfo...41555&jsn=2182

https://www.rockauto.com/en/moreinfo...41555&jsn=2180

 

Here is a picture of it.

 

You've pretty much got the procedure. If you are fully removing the throttle body, the only hard part can be disconnecting the electrical connector. Here's my trick: Push the connector in further, squeeze the tabs, wiggle, then pull. If that fails, look for which tab is hanging up and pry the tab away very slightly before pulling. Best to do this before loosening the 4 bolts so there is something to push/pull against. This connector can be a pain, and it can break.

However, replacing the O-ring and cleaning can all be done with the connector installed -- There's enough slack in the cable. Just remove the 4 bolts. The O-ring goes into a groove in the manifold, the throttle body is perfectly flat. I add a little grease to the O-ring for a better seal and easier removal.

 

It looks right, especially since the part number crosses. The 3.7 in the Liberty can use the same O-ring (gasket) as the 3.8L in the JK, but there is always a bit of doubt since they apparently made more than one style 3.8L intake manifold -- which is very strange. I'd just pull it apart and compare.

 

I've always pulled that connector, didn't seem to have enough slack for me to get really in there. If you loosen the other three, then go for that bottom right one then it's easier to pull. I also have the external torx in a 3/8" and it's fine. Maybe a swivel socket on that bottom right one, I can't recall. Yes to it being obvious on the install, it just sits in a groove on the intake.

 

OK I will get this done tonight hopefully and report back. I have a coolant flush and new brakes to do this morning on the rear.

 

Seems like I recall you having asked about cleaning the TB in the past. I guess maybe you just cleaned carefully in place? I've not removed the TB on my 3.6L much less a 3.8L, but I have removed several on other cars. Don't get to overthinking it. You are a smart and careful guy and won't be blowing anything up. That is odd indeed if someone used RTV on that.

You're flushing coolant already? Seems like you just worked on the cooling system not long ago (I recall you having that fancy bleeding system). Not to sidetrack the thread.

 

Here we go