1996 Chevy Lumina Overheating

GUNSTEIN

MEMBER
1996 CHEVROLET LUMINA
6 CYL
FWD
AUTOMATIC
160,000 MILES

The car started to overheat according to the gauge and dummy light. And it was idling rough. Pulled over and shut off, checked oil for mixture with coolant, checked radiator, both looked good. Radiator was full and oil was not white. There was no pressure in the upper or lower radiator hoses. No leaks. What should my next step be?

1 Reply

ERNEST CLARK

MECHANIC
1,730 POSTS

Are you saying that there was no pressure in the upper and lower radiator hose while the engine was hot?

Because that's physically impossible. If there's coolant in the system, and your engine is hot, there's definitely pressure in the hoses.

Now, while the engine's hot, feel the upper and lower radiator hose. If one is hot and the other is not, then your thermostat is stuck closed.

If the thermostat is good, then you'll have to check your water pump for flow.

With the engine cold, remove the radiator cap and start the engine. As soon as the thermostat opens, the fluid should start running out of the radiator. If it does, then your water pump is good. (Also check that the belts are tight)

Next, you'll have to pressure check the system. If the thermostat is good and you have proper flow, then you may have a blown head or intake gasket. This procedure is complicated and not necessary to explain unless everything else checks out first.

If not, write back and I'll help you from there.