98 GC Limited 5.2L rpm surge

raleighjeep06 · 10-18-2006, 02:23 PM

My Grand Cherokee Limited 5.2L has 136,000 miles on her. I have noticed, since about the 65,000 mile mark, there is an occasional surge in rpms. The rpms will jump up for just a second and then drop back down. This occured most often when I would engage cruise control, but more recently has also been noticed without cruise engaged. Someone suggested that it was tied to the sensor that determined when the 4x4 was needed. I do not know enough about it to determine the cause. Has anyone had a similar experience and if so, what was the problem and the big question...how much did it cost to have it fixed!?? Thanks

**ArloGuthroJeep** · 10-18-2006, 02:28 PM

Not sure what it is, but it isn't related to 4wd.

**Yardman Harry** · 10-18-2006, 03:27 PM

Is your speed affected? Are you jolted around in the Jeep?

hmm, sounds to me that its just the Torque converter doing its job. If youre not jolted around too much in the jeep then its a normal occurance. Does it happen when you hit a slight incline?

raleighjeep06 · 10-18-2006, 03:56 PM

The speed is not affected. It is just a momentary jump in RPMs and can occur on perfectly level road surfaces and for no apparent reason.

**Yardman Harry** · 10-18-2006, 04:06 PM

well, im not going to say that my jeep has never done that to me. But if everything else seems to be fine, idle, start up, performance, then i would say dont worry.

how many rpms are we talking about here?

**Woody** · 10-18-2006, 06:16 PM

I agree that it sounds like the torque converter doing it's job.

hugeorgan351 · 11-29-2010, 07:46 PM

i know what your talkin about my grand does the same thing about 300-500 rpms and i havent had any problems...one thing i do notice is my tranny shifts weird at times like it jumps up and down gears at certain throttle positions but otherwise its fine

proeliumfessus · 11-29-2010, 08:13 PM

newfieZJ recommended this link to me when I was tryin to smooth out my rpms... maybe it'll help

TSB 18-48-98

hugeorgan351 · 11-30-2010, 07:22 AM

thanks for the input

**newfieZJ** · 11-30-2010, 07:48 AM

Not sure if it applies to your issues , but , I do know when in overdrive , if you lift your foot completely off the gas , the TC will disengage from lock-up , then , when gas is reapplied ., the TC has to lock again . This will cause a 3-400 rpm jump until the TC locks takes just a sec or 2 . It's just the way DC makes em

10-18-2006, 03:56 PM	#4
raleighjeep06 Registered User Join Date: Oct 2006 Location: Raleigh, NC Posts: 2 Profile Gallery Classifieds My Jeeps	The speed is not affected. It is just a momentary jump in RPMs and can occur on perfectly level road surfaces and for no apparent reason.