Three problems related to manifold/header/muffler/tail pipe have been reported for the 2004 Jeep Grand Cherokee. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Jeep Grand Cherokee based on all problems reported for the 2004 Grand Cherokee.
While driving down the highway all of a sudden I heard a loud hissing sound. Noticed it was a manifold leak after further inspection noticed two bolts were broke on the drivers side, left side of the motor by the firewall. There is no possible way to remove these broken bolts other than pulling the motor. No mechanic will touch it. Therefore leaving the cost on the consumer. The grade of the bolts are very poor. They knew the 4. 7 v8 motor would not have enough space for the consumer to fix these issues. Leaving the consumer to pay thousands of dollars to fix their mistake it is not safe it is not fair. Now the consumer has to worry that's excessive heat that escaped out the manifold due to the broken bolts doesn't catch anything on fire under the hood while driving possibly injuring or fatally injuring the people in the vehicle as well as others driving on the road. I feel they should be responsible for there mistake. These bolts should not break off within 100,000 miles it is a hazard to the driver there occupants I feel they should have a recall. It's one thing if you just don't have the money to fix it it's another thing if you do and there's no possible solution that's not what I paid for now I have to drive a vehicle that I don't feel safe I can't trade it in or sell it because you can hear it now I'm stuck with driving it for another couple thousand miles and be out of the vehicle on their behalf.
The two rear bolts that attach the left exhaust manifold have sheared off causing a significant exhaust leak and poor engine performance while engine is cold. Based upon internet research this appears to be a common issue on 4. 7l v8 engines.
Noise in passenger compartment while sitting idle or at a stop sign as a result of a faulty muffler/exhaust system. Took the vehicle in to dealership who notified Chrysler of the problem. Their solution was a piece of barb welded to the muffler. Did not fix problem. Dealer had engineer come in to look at repair. Engineer said it was good and the noise was "acceptable" because we are only sitting idle for 3% of the time on the road. Dealer acknowledged that the noise was still there and said it was chryslers call and that there is nothing else to do. Took car to muffler shop where they immediately identified problem with existing muffler.