Alright guys a got a newer version of the old jeep 04 limited with the 4.7 ho but the rpm occasionally will rise and fall about 200 but only when cruise is on. Any ideas where to start?Ive figured that the brake booster is good cause well the brakes still work very well. So anything you guys can fill me in on would be greatly appreciated

 

It could be the torque converter clutch disengaging and locking again. Or even the AC kicking on and off that is causing the RPMs to fluctuate.

 

Yeah, 200 rpm sounds like the difference between converter lock-up and running free. The lock-up only reduces engine rpm by 10%. Early GM's had a lot of problems with "hunting" of the lock-up.

If you care, my 4.0 WJ converter clutch doesn't work and and I still got 20.4 mpg on a 70 mph trip of about 300 miles with the windows down. That's actual, not VIC reported.

 

Only does it when cruise control is on and if you sponge on the gas a little it stops for a while I know there are bigger issues but its the little ones that bother you the most.

 

Yes, it's those nagging little hiccups that keep you wondering what's about to fail.

 

Do you have the computer for the 04 4.7HO motor in yours when you swapped? Just wondered if that could be an issue and were the trans the same in both of them?


I also have a 04 Overland 4.7HO and have never really noticed this issue other than those times mentioned.