I own a 1999 Durango 5.9L, 4x4, with towing and off road package and 221,000 miles (I am the original owner). I recently returned from a 3,600 mile road trip. Before leaving, I had an oil/filter change and a new air filter. I also had the thermostat replaced due to a slight leak around the gasket. Keep in mind, this was the original thermostat.

My vehicle has never had an overheating problem except when the water pump went out and was replaced in 2011. About 1000 miles into the trip the vehicle started overheating, the Check Engine light came on and it started idling rough. I was in Oregon at sea level and made it to Portland where I took it to a reputable mechanic recommended by a relative. He ran a diagnostic and found the #4 cylinder was not firing. He also noticed a coolant leak around the timing chain cover and thought that could be causing the overheating. The $725.00 repair entailed a complete tuneup, replacing the timing cover gasket and replacing the thermostat with only about 1,000 miles on it.

The vehicle was running at normal operating temps until about 1,500 miles later. The temp gauge then started going from normal to about 3/4 hot. Checked coolant and had to add about 1/3 gallon. Problem continued to get worse till the gauge went into the red. Adding coolant didn't help and the heater was blowing cold air. The vehicle ran fine.

I don't see any leaks but I went through 3 gals af coolant during that trip. Any ideas?

 

No puddles under the truck? Not a good sign. Possible blown head gasket. See any white smoke out the exhaust?

Have you fixed the plenum yet? Any issues with oil consumption? Poor fuel economy? (worse than normal.....)

May wanna post up in the Durango section as well. Lots of knowledgeable folk there.

 

Welcome to DF! Be sure to check out the Durango section.

 

Just did an engine run up. Temp gauge got hot. Felt upper and lower radiator hoses. Top hose was hot. Lower hose was cold. Sounds like a circulation problem since the heater doesn't get hot. Any guesses on the water pump?

 

And, BTW, no white smoke coming from tail pipe and engine runs fine.

 

Sorry. I thought I was in the Durango forum. How do I post in there and can I transfer this post over?

 

Just go to the right forum for your year durango, and hit the 'new thread' button. You can't move you your posts.