Hello, this is my first post here as I am a new owner of a Blazer as of last week. It is a 99 4 wheel drive with the 4.3 Vortec.

Yesterday I was on the highway and accelerated and the car started smoking and the heater stopped working. It wasn't overheating to I got it home and opened the hood to find that the entire driver side of the engine was dripping with coolant. I assumed the smoke was the coolant burning off so I got it all cleaned up. I went through and checked everything the best I could even though I am not sure what I am looking for. The radiator was very low but the reservoir was full so I put coolant in the radiator. When the engine begins to get hot, smoke starts coming from an area behind the AC compressor almost where the top radiator hose connects in. I could not find a leak in the hose or around the connection and when I turn the car off to look around the smoke stops. I have no idea what course to take so I'm hoping someone may have an idea what to do.

Thanks.

 

You need to pressure test the system while engine off. This should show you the leak.

Cooling System Pressure Tester | Princess Auto

Good Luck

 

Pressure test will pin point the leak(s). Check the metal riser tube that the hose connects to...it's prone to rust through.

 

Since the leak seems to be coming from that general area I am going to replace the upper hose, goose neck, and thermostat tomorrow. The goose neck is in awful shape under where the hose was fastened and that end of the hose was full of gunk and particles. I figure if I am taking the parts off anyway, why not change the thermostat too since its fairly inexpensive and somebody brought up to me the idea that it may not have opened correctly and the pressure was enough to cause the leak in the first place.