2005 Grand Caravan, 3.8l, 450,000 miles. Replaced thermostat and radiator @ 18 months ago. Temp gauge has always read at the mid point (@ 98 degrees) since then. In the last few days it has started to read at 3/4 to hot on the dash gague. Fluid level in reclaim was just below minimum. Topped it back up to 3/4 way to max. Used Torque App on phone to get real time temp and it reads @ 116 degrees when gauge in car reaches 3/4. Heater blows hot, upper radiator hose is warm but not excessively hot (can hold hand on it for 5 seconds), rad cap is cool.

Should I be concerned if temp is @ 116 degrees (@ 18 degrees higher than it normally ran)? Wondering if maybe has developed a small leak that is letting an air bubble into the system or perhaps the temp sensor is bad. With the high miles, the water pump could also be suspect.

 

Does this van have the factory WP still running after 450K miles? If so, that's remarkable! They usually beging to weep at the start of the trip South, so that's something for you to check. You mentioned the overflow was low, but what about the radiator - was that low also?

 

I first look for leaks,
second if I want to keep this vehicle I probably do a flush on the fluid. not sure how old it is. replace the water pump. replace the thermostat. consider replacement of lower and upper hoses if they not in the greatest shape. and replace the radiator cap. fill it back up to proper level.


third. you could do a pressure test to the system see if you leaking fluid thru the engine or other places.

 

These vans run at midpoint or below normally unless in the desert perhaps.

A leaking pump is not the only way you can see if its bad. If you are not the original owner its possible someone replaced it already with a plastic impeller.

See THIS POST for info and the last reply made by me with a pic of the plastic damage.

 

dam I will check on new pump if I ever change make sure got metal impeller. try back flushing the parts out. unless someone here knows better solution.

 

Heh! I pulled the bottom tube, the lower radiator hose, the upper, and the T-Stat housing looking for fragmentation and flushing with garden hose from all orifices and found nothing.

I suspect they are in the radiator side tank and cannot go anywhere.

And I did get a metal impeller pump from Advance Auto. tjhey have two and I had them show me both, one being plastic and the other metal. Thats why I did not mail order one.

 

Thanks for the replies. I bought the van in 2011 with 131k miles on it and I used it for long haul deliveries putting @ 150k miles per year. Bought another just like it in May and was going to scrap this one. My wife drives it to work @ 5miles per day so decided to see just how many miles I could get out of it. I'll check out all you suggestions and hopefully it's a simple fix. I'll let you know what I find. Thanks again.