Hi everyone,

I have a 1984 Z28 with a 350. I am having an issue with the vehicle overheating at idle. I replaced the radiator and thermostat. The vehicle does have coolant, 50/50 mix, the hoses are not getting hot and the temp gauge is spiking past 260 deg. The vehicle is overheating within 5-10 min during warm up. The fan is working. I am running out of ideas and could use as much help as possible

Thanks

 

if the hoses are not getting hot, there is no coolant flow. the top hose should get hot when the thermostat opens.

remove the thermostat completely and see if you get coolant flow and cool running. if that works you have a bad or incorrectly installed thermostat. the coil should be down on the thermostat.

if you still have no flow after removing the thermostat, you either have a blockage or bad water pump. water pumps usually leak when they fail, but it is possible that the impeller is rusted out or come off the shaft.

 

U might also change thermostat to 185* from 195*. The reason for the high temp thermostats is really for emissions. I owned a 1972 Buick GS 350 & the recommended therm was 195 but u would find that just about every owner of the a-body cars were using 185* therms.
I installed a new 195* in my '84 TA & when I check the temp at the thermostat housing it reads 210--212*. If I have to remove the housing I would drop to 185*.
Is your clutch fan engaged at idle?

 

Have you verified that the engine is actually reaching 260, or are you only going by the car's temp gauge?

 

1. air dam
2. faulty thermostat 9there was another post where someone got 2 bad ones)
3. air in the system
4. Bad coolant flow

 

Lots of good advice here. An infrared thermometer is a great tool to have for tracking down overheating issues, the gauge is useful for identifying trends but should not be trusted as a source of truth.

 

 

When u are about to install, drill a small hole in the t-stat which allows for the system to burp after a refill.

 

You can also buy thermostats with the hole already present, like the one I have..

 

if your engine is really running at 260*, soon it will seize & die. There is insufficient in the block to take that temp. Head gaskets s/b failing.