I just bought a 2000 Dakota Sport (4.7 V8) w/ 100K miles. This truck is awesome and I'm totally happy with it... but I've noticed that the temp gauge fluctuates from the "normal" 210/220F to up close to 240/250F when I'm on the highway driving 70mph and up with RPM's around 2500. As soon as I let off the gas and go back to slower speeds the temp goes back down. The gauge never goes above 260F or in the RED but it gets close. Occasionally, I hear a gurgling sound coming from the radiator cap area when I shut off the engine, but not all the time. I have noticed a small amount of anti-freeze overflow on and around the engine, but not much, and the fluid level is still good. I'm concerned that when the weather turns hot my truck may overheat and I want to fix any potential problems before I end up hurting my engine. Should I be worried? Is this normal? Please help.

 

Correct mixture of antifreeze? Radiator cap good and correct pressure?

 

Thanks. So you think I should start there with the antifreeze and/or the cap? If that doesn't fix the problem, then what's next? The thermostat?

 

get a mixture tester. my friend had a dodge intrepid and he had to much antifreeze and not enough water and he boiled the fluid and it exploded everywhere haha

 

Thanks. That's what I'll do first.

 

After making sure you have the right mixture in there (the 2000 FSM recommends a 50/50 mixture of water and antifreeze), I'd "burp" the cooling system to make sure there are no air pockets trapped in there. If that doesn't fix it I'd replace the thermostat. Alternately you could test the thermostat in a pan of water on the stove to see if it needs replacing, but they are cheap enough that while you have it apart anyway, you might as well replace it.

 

Mine was doing the same when my water pump was going. Most tend to leak but mine would only drip a few drips right after it was turned off.