2001 L100 over heating after thermostat change

[DKW1977]

Hello my car started overheating on my way home from work yesterday. I purchased a thermostat removed the housing and to my surprise there was no thermostat in it. I put the new thermostat in and it is still over heating. Can anyone tell me what can cause this to happen. I thought it would fix it but clearly it didn't. By the way I just purchased the car.

[Crvett69]

sounds like they knew it had a problem and removed the thermostat trying to fix it. make sure you removed the right housing, thermostat could be hooked to bottom or top hose where it attaches to the engine. there may also be a bleed screw you have to loosen to get the air out of the system. if thats all ok them you need to see if the fans are coming on if its overheating in town. if its on the freeway then you need to have the radiator flow checked. if its losing any water then you have to look into stuff like a blown head gasket or leaking water pump

[Ruley73]

What reading does the temp gauge indicate? Do you observe any symptoms of overheating like coolant boiling out of the reservoir and/or visible steam?

Confirm the coolant lid/cap is holding pressure. You can just replace the cap since they are really cheap or have the cap pressure tested at your local AutoZone. The boiling point won't be raised if no pressure is applied to the cooling system. This would make the coolant boil prematurely.

Make sure that the water pump is circulating the coolant. Remove the coolant lid while the engine is cool. Then start the engine and rev it up a few times. You should see coolant flow in the reservoir as the engine is revved up. If you don't, then the water pump is not moving the coolant. A possibility is that the balance shaft chain (which drives the water pump on the Ecotec engines) has come off the sprockets. This doesn't occur very often, but it is certainly a possibility.

The cooling fan doesn't turn on when driving at highway speeds under normal operating conditions, but it wouldn't hurt to check and see if it runs. If your A/C is working properly, the cooling fan should come on when you turn the A/C on while the vehicle is parked.