Loss of power at highway speeds

Hi everyone! I purchased my “certified” 2012 Jeep Grand Cherokee Limited 4x4 5.7 Hemi last July (2017) from a “Certified Dealer”. It had 68,000 Miles. I am currently at 76,000 miles and am experience an issue that I am praying isn’t serious! I need to downshift the auto transmission once vehicle reaches cruising speed due to “symptoms” of low idle. The RPM’s display doesn’t necessarily show a drop, but that is what it feels like when this happens. This is happening around town and at highway speeds. It reminds me of my manual transmission driving days when in a higher gear at a low speed if that makes sense. It is consistent. It does help to “downshift” into a lower speed, but this shouldn’t be happening. I don’t know if I’m just super tuned in now, but it seems like the engine in general seems to be running “rougher” than normal. Anyone that has experienced this or that can tell me where to start would be very helpful!!

 

The engine has a noticeable loss of power. You can feel a vibration throughout the vehicle. You either have to accelerate or downshift to get it to stop. However when you accelerate, it’s only good until you level off speed....

 

Do you have a stock exhaust or is it a louder more free flowing after market. I once put a custom 3 inch exhaust on my Chevy truck and the resonance and vibration was so bad at cruising speed that after a month I couldn't take it anymore and went back to my stock exhaust. Could this be your issue? It felt like a fine humming vibration throughout the whole vehicle and would only go away when in a lower gear. No power loss just a higher gear good only for cruising.

 

As far as I know it is stock exhaust. I haven’t done anything to the exhaust since I got it. I did have to replace the water pump....hoping I don’t have a lemon! I’ve only driven it for 8,000 Miles...it is in the shop today. I will update once I know!

 

If you havent done it you might replace the air filter. An old filter can cause power robbing and is part of necessary maintenance that is often neglected.

 

Ok, so brought it to my local mechanic. Off to the dealer I go! “Service Bulletin”:
http://www.wk2jeeps.com/tsb/tsb_wk2_1810816.pdf
Hopefully this will fix the issue!
Thanks to all of you that tried to help!
Fingers crossed that this works! I NEED my jeep!!

 

Welcome to the forum Jcwx5. Good luck with the recall fix.

 

Thanks! I never got a “recall” for this....I found out from my mechanic about this “service bulletin”. I just had it into the dealer last month for a recall on the brake booster (which they told me was fine). Hmmmmm.....

 

Sorry for the delay! My Jeep
Is fixed!!! I still can’t believe it, but it was a transmission mount that was worn down. They told me all of the software was up to date.... $411 later, I drove away. A few month ago, I had to have the water pump, thermostat and belt tensioner replaced to the tune of $600. I wasn’t expecting to have to put that much cash into a “certified Jeep” within the first 8,000 miles of ownership. Hoping that’s it for a while.....For now, Jeep is running like a champ once again! Hope this helps someone else down the road! Thanks for all of your input! Very much appreciated!

 

Thanks for the update as the badly worn trans mount affected driveability, noise and vibration....things that should have been noticed while being"certified". Dealer service charge for the waterpump, thermostat, belt tensioner is not too out of line.