Overheated is it the engine or thermostat

CONNIE CAMPBELL

MEMBER
2015 DODGE CARAVAN
78,000 MILES

Broke down, car overheated. Dodge dealership ran a diagnostics. They said they would have to put a hose on the car ($500.00), then they would be able to tell if it the engine or thermostat. They seemed shady and this is all they could tell us. Would the diagnostics tell them if it was the engine or thermostat?

1 Reply

SCGRANTURISMO

MECHANIC
4,897 POSTS

Hello,

If the vehicle overheated it was probably due to the thermostat. The worry here is if any damage happened to the engine when it overheated. Usually when a vehicle's engine overheats the damage happens to the aluminum cylinder head in the form of warping due to aluminum's lower melting point (around 800 degrees). This causes the head gasket to fail, requiring a new head gasket and your cylinder head's mating surface to be shaved and re-flattened out. Here is how to check if your head gasket is damages or not:

https://www.2carpros.com/articles/head-gasket-blown-test

Usually your vehicle's cooling system will fail with the thermostat, which will stick closed not allowing the coolant to circulate, or the water pump will fail, again, not allowing to coolant to circulate. Sometimes clamps on hoses fail or the hoses themselves fail. To check to see where your cooling system has failed go to this link below.

https://www.2carpros.com/articles/radiator-pressure-test

Please go through these guides and get back to us with what you are able to find out.

Thanks,
Alex
2CarPros