2002 Chevrolet Trailblazer Running hot and don’t know why?
Running hot and don’t know why?
What is your question?
I have an 02 Chevy trailblazer and I replaced the thermostat and the water pump is cleaned. I can drive my truck one day a good 10 miles and it runs hot. Tried to do the 10 miles again didn’t run hot. There’s no leaks when it did run hot. Scared to drive it around because it will get hot again. I had someone tell me it runs too good to be the head gasket. I am in the process of changing my radiator hose and flushing the radiator. When it did run hot the water jug was boiling. Now today I tried driving it around my house area and it didn’t run hot but if I were to drive it to town I am not sure when it will run hot or if it will. There’s no leaks from the tailpipe neither but what should I do next? Buy a new radiator? If that’s not the problem then what? Should I still buy a bottom radiator hose and flush it? It doesn’t run hot when it’s ideling. And ac doesn’t effect it On or off.
How long has your 2002 Chevrolet Trailblazer had this problem?
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Hello, regarding internal engine coolant leaks, such as with a head gasket failure, the most evident thing that is helpful for me -- not scientific at all, but something that makes total sense is to check the coolant reservoir (cold) for how it smells. It should smell like coolant and only coolant. If it smells like exhaust at all, you likely have an internal engine coolant leak. This is because exhaust gases put pressure into the cooling system due to the internal engine breach, and exhaust gases are pretty easy to notice smell-wise.
"The water jug was boiling" -- if you have a proper 50/50 coolant to water mix, you should never have "boiling" -- it's another clue that there could be exhaust gas back pressure in the cooling system.
Erratic overheating is also a clue -- along with the two other symptoms mentioned. But it's really hard to say, and all those "clues" do not guarantee that is what is happening.
Have you ensured the cooling fan is functioning as designed? You mention it does not run hot when it's idling, so that leads me to believe the cooling fan is a non-issue.
Incidentally, that can be another clue of an internal engine coolant leak...
When you say "water pump is cleaned", what does that mean? It is rare for a water pump to "fail" - the impeller could separate but that's super rare and would result in consistent overheating, not intermittent overheating.
Good luck!
Okay so when it ran hot all you smell is coolant. Now when it runs cold it does not smell anything. It’s like the truck runs fine for so long and then it runs hot. It only boils when it runs hot. Like the water jug is about to explode type boiling. Like it seems like it almost melts the water jug but there is a leak when that does happen. When it gets hot it leaks by the water jug but it doesn’t look like it over flows. And when it say it is clean I mean that my dad had took out the water pump looked at it cleaned it with whatever and put it back. Now I had to bypass my heater hose because that did bust and I didn’t wanna buy another one because I would have to get into the engine. And when my dad bypassed it, it doesn’t leak there at all. I just don’t want it to not be those things and I spent all that money on a new radiator and hose and that still isn’t the problem. I even changed the thermostat and it doesn’t leak there neither. It’s almost like imma have to fix the radiator and hose and drive it til it gets hot, if it does, just to find out where the leak is if there is one. I have AAA so I can get towed within 200 miles but I want to see the problem before I pay for a new radiator or hose and flush it.
Does overheating ever occur while driving at highway speeds? ... Have you noticed the check engine light - service engine soon light on while driving?
Engine is equipped with electro viscous radiator cooling fan that is controlled by ecm - intermittent failures are common - should have trouble code stored.
Also research > Combustion leak test.
I’m really hoping it’s not the head gasket but I’ve been told it runs too good for it to be the head gasket. And I haven’t made it to a highway to test it but when we left my house when it over headed we went from speeds 40-65 and it over heated. When I went test drive it yesterday I drove over 65 mph and it didn’t over heat. Check engine light is on. I have watched this video saying if you move the fan then it is your water pump but you cannot move my fan at all. The fan looks brand new. My dad works as a mechanic and said it shouldn’t be the fan because of how clean and good it looked. So should I change the radiator and hose and flush it anyway. If it isn’t those two things it’s gotta be the head gasket right?
Okay so when it ran hot all you smell is coolant. Now when it runs cold it does not smell anything. It’s like the truck runs fine for so long and then it runs hot. It only boils when it runs hot. Like the water jug is about to explode type boiling. Like it seems like it almost melts the water jug but there is a leak when that does happen. When it gets hot it leaks by the water jug but it doesn’t look like it over flows. And when it say it is clean I mean that my dad had took out the water pump looked at it cleaned it with whatever and put it back. Now I had to bypass my heater hose because that did bust and I didn’t wanna buy another one because I would have to get into the engine. And when my dad bypassed it, it doesn’t leak there at all. I just don’t want it to not be those things and I spent all that money on a new radiator and hose and that still isn’t the problem. I even changed the thermostat and it doesn’t leak there neither. It’s almost like imma have to fix the radiator and hose and drive it til it gets hot, if it does, just to find out where the leak is if there is one. I have AAA so I can get towed within 200 miles but I want to see the problem before I pay for a new radiator or hose and flush it.