2002 Ram 1500 4.7 liter I just had the head gaskets changed on my truck get it back from the mechanic and the temp gauge will steadily climb if I go over 70 mph. But If I back off of her to say 55 or 60 the temp gauge will be fine. Change the t stat three months ago so I can't see it being that. Any help would be great. Thanks

 

They should have put in a new t-stat when the head gaskets were changed. But IMO I would take the truck back to the mechanic before more problems arise.

 

Could be as simple as an air bubble in the cooling system......

 

Could very well be a clogged radiator. I had a similar issue. Needed a new water pump so I did a new thermostat as well as an e-fan . It would still heat up when going up a hill on the interstate. New radiator solved the problem for me.

 

was the fins on the radiator all bent over or could you see through it I can see through my radiator unless it and internal clog or build up.

 

Since you replaced head gaskets Im assuming you over heated it. But did you have the heads checked for cracks and resurfaced?

 

Just had to deal with this problem. My truck did it for about 2 years. Driving around town it was fine, but as soon as i got on the highway it would start climbing. Put a new t stat, and fan clutch in it and it didnt help a bit. Finally got aggravated and bought a new radiator and a water pump, problem solved. Stays below normal on the highway now. Radiators in 3rd gens have a bad problem clogging from what ive heard.....

 

I figure it would be the other way for me. Highway would be fine but would overheat in no time in traffic.

 

i will try the radiator

 

Radiator. I went thru this issue on a friends 97 Ram. Around town it stayed about 200* but on the highway, it would slowly climb until it oveheated. It was partially clogged and didn't have enough cooling surface area left to keep it cool when the coolant was flowing fast at higher rpms.