Durango SLT 5.9L

• Automatic transmission
• 240,000 miles

Well I bought my Durango when the temp was cooler so I didn't really notice the overheating problem till summer came around this year. Now that it gets to 90+ degrees F and the coolant temp running over the edge of the safe limit (which is about 230 degrees and is bad even getting close to that temp in the first place) so I had to do something. Started by removing the thermostat. Did run a little cooler, but still ran too hot. Weird thing is it would heat up to a certain point, but from a stop, if I accelerated fast, it would get hotter and didn't seam to cool down to the level it was before I stopped. I figured it had to be my radiator since my heater could cool down the engine temp 10+ degrees.

I also found out something interesting... I have the tow package which has the auxiliary transmission oil cooler and I imagine that it is fine so I should only need to get the radiator, right? After calling multiple radiator manufacturers, I found that if you just buy the radiator, you can't reattach the old aux cooler to it because it doesn't have the mounts for it. It appears to hook up to the same ports and you could just reuse the one line, but mounts are different. I imagine you might be able to fab up something so you could reuse your old one, but I didn't want to spend the time or the money.

So I replaced the radiator with a new one I bought from ebay... It was less than $250 with shipping inc. and autozone had one for $400 so I just decided to get the $250 radiator. It actually is a really nice radiator. Even at 90 degrees outside, the engine only heats up to about 150 degrees (thermostat is still out) with the A/C on! Only problem is that it doesn't hold pressure. I can squeeze the hoses with the engine cold or hot and I can feel the coolant flowing into the overflow reservoir. The biggest problem I can think of is it will let it evaporate quicker requiring you to refill the coolant more often. I don’t know what’s going to happen when I reinstall the thermostat and forces the engine to run hotter either. I’ve tried my original coolant cap and a new one, both with the same result. I’m thinking about returning it as being defective, but I can imagine that the next one will be the same and I would have to pay shipping one way for nothing.