Have Jeep Questions? Ask a Jeep Repair Expert for Answers
Hello. Welcome to Just Answer. Is this a 4.0 litre engine?
The first thing you need to do is ensure you have the correct water pump. On this engine, there are two choices of water pumps. The pump on the engine runs backwards. This is normally identified by a "R" on the pump body. if you have the wrong pump, the impeller is not pushing coolant thru the engine fast enough. This will give you an overheat condition. The best thing to do here is go to the parts store and look at the Reverse (the R unit) pump and the non-reverse (no R) pump. Compare it to the one you have installed now. If you have the wrong pump, the correct pump should fix the issue. Reman pumps sometimes do not fit the correct impeller to the pump body; this is sadly common with the reman market. Your absolute best bet here would go to a Jeep dealer parts dept and have them show you the pump you need to have installed; then compare yours. If you have the correct pump, and the impeller is fitted correctly, and turning the proper way, you may have rust sediment built up in the cylinder block. This would become cause to chemically clean the cylinder block.
This is something best left to a shop. The chemicals you can purchase in an auto parts store is not as good (performance wise) as you find in a professional shop. Leave this one to the pros. You will get a better job and won't waste your money.