This might sound dumb but was messing around today and revved the mighty 3.8 while in park to find out that it won't rev very high and it is spurratic. One time it reved to 2k rpms and the next time it went to 3k rpms. Once it reved to 3k then cut back to 2 k and pulsed from 2k to 2.5k rpms. All while the gas pedal was to the floor. Is this normal with the electronic throttle control, like a safety precaution. I was curious about it so i took the jeep around the block in first gear and it got up to 4.5k rpms. Just wondering. Sorry for my idiolscense if it has been posted already.

 

en.wikipedia.org/wiki/Rev_limiter

Design feature. You are allowed to rev it to a predefined limit while in Park. You may want to do this for diagnostic reasons or if you are winching or giving someone a jump start. Fortunately it appears yours is working well within parameters.

Is there a reason you are trying to grenade your engine?

 

Well i'm not trying to grenade it right yet, but was just messing around and it seemed odd. I thought maybe something was up with the 3.8 and i wanted to make sure it was normal. Only did it a couple times. But if i DID grenade it, it would give me a good excuse to swap in a hemi. HAHA. Plus i have a full lifetime powertrain warranty and the dealership i got the jeep from knows me very well. I've boughten many of vehicles there and they've always been good so i'm sure if i did blow it, i could get a new engine under warranty. But i won't be doing that again. Thanks for the input and comments

 

Turn off ESP and try it. If I remember correctly you can rev it then.

 

you are having the opposite problem that toyota is having LOL

 

HAHA exactly. I think Toyota might want to give the engineers at Jeep a call. I've never really experienced the limited rev in park like that though. Every vehicle i've owned was able to rev to the limiter in park. I guess its a good thing to have to save the engine.

 

I had this same "issue" last week. I changed my oil for the first time in my JK, and as I always do, I revved it a bit to make sure everything was good to go and hit a limit at 4k RPM's. I had never encountered this before (I'm a former high revving Honda/Toyota engine guy) so I was worried something was wrong but apparently it's the norm.