2003 silverado 2500HD Duramax 195K miles. Hello. I have a coolant issue. Today the heat would not work. This happened last week once also, then it worked. About 10 minutes of driving in the cold today...the coolant temp was getting way too hot. I took it home and parked. At first I was thinking thermostat (because I had to heat) then I was thinking water pump (because the coolant temp was so hot. What do you think?

 

If you have no heat, perhaps you might have a blockage in the hose going to or from your heater core (sort of like a reverse radiator).

A stuck thermostat could also be the culprit.

When you get the truck to operating temperature, feel the bottom of the radiator AND the top of the radiator. If one part is hot and the other one cold (after you reach a temperature at which the thermostat should open), there is a great chance that could be your problem. If the thermostat will not open, the hot water won't be able to circulate - which makes your truck overheat quickly, even though one part of the radiator is cold to the touch.

Good luck!!

 

Thanks. That gives me something to try in the morning. Could be something stuck. I did have a leak somewhere last summer...and put a couple bottles of that crap that's suppose to seal up the leak. I don't know if that was a quick fix to create a bigger problem.

 

Barr's Stop-Leak?

That stuff generally works for a short-term fix, but you are rolling the dice as to whether or not it may cause more trouble down the line.