My 01 GMC Sierra 1500 is overheating. Sometimes
it'll drive for a few minutes before it overheats and
another time it can drive for almost an hour.
Replaced head gaskets , thermostat, temp sensor.
No oil in water/coolant. Heat and AC work. What
could the problem be?
Nothing you said points to anything specific, but I'd begin with the cooling fan. Is the overheating problem more at high speeds or near idle? Fans work constantly with AC on. Turn on the AC and see if it runs. If it does, you probably just have a defective engine coolant temperature sensor. If not, you might have a blown fuse or relay, defective fan clutch or wiring, bad fan temperature switch, or bad fan motors.
Ed92626 Would a fuse or relay make the water boil over? The fans work with/without ac on. The truck doesn't overheat while idling only while driving simply around the block. Sometimes it can take a few minutes to start overheating and another time it can take up to an hour. Replaced the head gaskets (both) and temp sensor and thermostat. Fans work fine and waterpump seems to be working fine also
If you don't know cars, don't speculate at what the problem might be. Have a mechanic find it & fix it. I'll explain overheating. Overheating can be caused by several things. A broken water pump, sticking thermostat, clogged radiator, collapsed hose, bad radiator cap, air in cooling system. Could be a defect in the cooling fan system causing the fan not to operate when needed. There could even be mechanical issues with the engine that cause this. Start by checking coolant flow. Is the top hose hot? if not it's the thermostat. If it is, with radiator cap off see if there is flow. If not, it's the radiator. If flow, purge air from the system (videos on line explain this simple procedure). This covers 90% of overheating problems..... When you had the work done, the mechanic might not have purged air from the cooling system and that simply might be your problem. Have your mechanic diagnose this & fix it.
Looking for a Used Sierra 1500 in your area?
CarGurus has 9,496 nationwide Sierra 1500 listings starting at $2,500.
Search GMC Sierra 1500 Questions
Find great deals from top-rated dealersSearch
Related Models For Sale
Used Cars for Sale