01 Tahoe No Heat Sometimes

[CorbinC124]

So when i go to start up my truck and let it run, right before it gets up to temp the heat works fantastic but as soon as it gets up to temp the temp on my gauge just drops and i have to let the heat kind of almost charge up to use it, also i have a steady coolant leak but cant find from where except that it drips from the front clip. when i dont have coolant in it the heat works great but as soon as i refill the coolant i get this problem. any advice would be appreciated

side note it has enough in it usually that i dont get the low coolant light but my reservoir is almost always empty and the oil is not mixing with coolant

 

[Tonyv__]

So when i go to start up my truck and let it run, right before it gets up to temp the heat works fantastic but as soon as it gets up to temp the temp on my gauge just drops and i have to let the heat kind of almost charge up to use it, also i have a steady coolant leak but cant find from where except that it drips from the front clip. when i dont have coolant in it the heat works great but as soon as i refill the coolant i get this problem. any advice would be appreciated

side note it has enough in it usually that i dont get the low coolant light but my reservoir is almost always empty and the oil is not mixing with coolant

Well first things first, you have to figure out where you’re loosing coolant. You’ll just be chasing your tail on the heat situation until then.

Once you get the leak fixed, coolant properly filled and burped. Then reevaluate the heat situation.

 

[Joseph Garcia]

Agreed. Get the coolant loss issue fixed first. Who knows, your heat issue may be resolved in the process.

 

[Fless]

Agree with the above suggestions.

And it sounds like the thermostat is opening, and it's either faulty or the wrong temp. Monitor the engine coolant temps with a scanner to see if the engine is getting up to around 200 deg F temp.