i have a 2001 blazer. i noticed it was overheating and i could smell coolant and saw i had a fairly decent leak toward the back of the engine. although my temp gauge was reading over half there was not hot air blowing from my defrost. when i refilled my coolant the temp went down and the heater blew hot air for a lil while then it stopped and overheated again. please help!

 

If you have a leak, you will want to get it fixed.

As far as why it overheated again, you likely didn't get all of the air out of the system. These trucks can be pretty stubborn when it comes to releasing all of the air from a cooling system. Having a leak doesn't help things either.

Until you get the leak fixed, I would recommend you keep a close eye on both the coolant level in the radiator and the engine oil condition.

 

Low coolant level will resuly in overheating and lack of heat. If the leak is at the rear of the engine check the corners of the intake manifold for a leak.

 

Yep, it is probably you intake gaskets. I have a 2001 also and will be replacing mine this weekend common problem with these 4.3 engines. The dex-cool anti-freeze is the culprit, they eat away at the intake gaskets. Get the fel-pro revised intake gasket set, this will solve the problem. Part number is MS 98002 T.

 

Couldn't be further from the real truth that GM chose the wrong gasket frame material for the job. The same thing can and does happen with regular green antifreeze. But we have an entire thread dedicated to that topic.

That is the best gasket for the job!

 

X2