Overheating 2005 Grand Cherokee

[Cool Ridge Jeep]

Hello! I'm new to this forum but was hoping I could get your help. I have a 2005 Grand Cherokee Laredo, 4.7 L, Quadra Track II Full time 4WD. I'm getting it prepared for a cross country trip. One of the last things I decided to do in my maintenance was drain and replace the antifreeze. I didn't flush the whole system. I just opened the radiator drain plug and let drain out what would come out...which ended up being a gallon or so fluid. Then I closed it off and put new Dextron (pinkish red type) antifreeze back in. I filled the radiator until it was within 1" of the cap, then ran the engine for a few minute to circulate the fluid and then added more to bring the radiator full and added fluid to the overflow tank. I took off down the road and it started showing hot on the temp gauge within a few miles. I pulled over and let it idle and turned my cain heat on full and directed it to the floor to help vent the heat. I noticed that the air blowing on the floor wasn't particularly hot. I drove it back home and it still heated up to "H" on the gauge and told me to check my gauge. The upper radiator hose was very hot and the cooling fan was blowing constantly. Any ideas? I've never had overheating problems until I drained and refilled the radiator today. Sorry so long of a story.

 

[SteelHeadz]

Welcome to Jeepz David. The most common causes for an overheat after a coolant drain and fill is due to an insufficient purging of air trapped within the cooling system. In your case, a 4.7 and likewise with the 3.7 liter engine, there is a bleed port located on top of the engine where the radiator hose attaches to. If i remember correctly it's a 8mm hex bolt. With the engine cold, start and let idle with the radiator cap off. loosen the hex bolt bleed screw and see if air purges out from the breach. Keep topping off the radiator as it goes down and repeat the process until there's no longer a sign of air in the system coming out of the bleed port. Last but not least, make sure coolant is a 50/50 mix with water.

 

[Cool Ridge Jeep]

Thanks Mikey. I appreciate the help. I spotted that bleeder late last night and I opened it. I'm going to follow your dirctions this morning. I've already done the diff fluid changes, transfer case, transmission, belt, oil, plugs and air filter. Getting ready to tow a couple of 4 wheelers across the country and go camping in Colorado and I hit this snag.

I also have a '65 CJ-5 that I salvaged and parked, waiting for rebuild. I'm sure I'll be back to Jeepz when I tear into that as well.

Thanks again.

David