Having problems with your 1994 Chevrolet Suburban ?
Heater problem with 1994 Suburban. have replaced radiator, thermostat (3 times). Also flushed the system and have run water (via garden hose) directly through the heater core. the flow seemed good. The issue is that we get very little heat out of the heater. Watching the engine temp from a cold start, it will heat up to about 210 degrees and then you can see when the thermostat opens. It's a 195 degree thermostat. Even at that point not much heat from the heater. Once the thermostat opens there
If your temp is jumping between 150-200 degrees then I am guessing you have an air pocket in the engine where coolant should be. The air pocket moves through the engine and when it gets to the water pump, it looses prime and doesn't move the antifreeze which causes it to warm up. Take the radiator cap off the radiator when the engine is cool. Start up the engine and let it run until the thermostat opens up. As the air moves it's way to the radiator it will escape and you will see the antifreeze level go down. Watch it run and as the level goes down add antifreeze until the radiator remains full. Then make sure your overflow tank is up to the required level and I bet your heater works a lot better after that.
There is a blockage in the heater box. Some vehicles have a cabin air filter which can be cleaned/replaced. Others have to manually clean the heater core fins in the heater box.
Repair Help & Product Troubleshooting for 1994 Chevrolet Suburban
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