[Runaboveit]

I was having the same problem. Would only get hot when on the freeway or at a steady engine load. Turned out there wasn't a thermostat in the car (this was shortly after I bought it and was checking everything out). Put a thermostat in, and the heat was good. A week later it started doing the same thing and I would hear a gurgling sound under the passenger side after the car was off. Air pockets were in the system.

Before I had time to work on it, the air in the heater core I'm guessing became acidic with the dexcool coolant and the heater core took a dump and started leaking coolant everywhere. Bought some 5/8 heater hose and bypassed the heater core. Actually bought a new heater core and heater core hoses along with two of those plastic quick connectors but never got around to fixing it and ending up returning it all. With the connectors, hoses, clamps, and heater core it all came to about $130 for the parts.

Anyway, thats my story.

Had I known how to bleed the system I would probably still have heat right now. Always learning something new. But the bleeder screw is on the front left of the engine (as if you open the hood and are looking down on the engine. look to the left front). You will see the long black pipe that runs across the front of the engine.. follow that to the left by the water pump and you will see a brass colored nut and screw looking thing. From what I have read, you have to hold the bottom part of it still while turning the top part of it to open it. I have read some people say to do it with the car on or off. I would think the best way to do it is while the car is cold or has been sitting for a few hours. Start it up and then open that top part of the valve/screw and wait until a steady stream of coolant is coming out and then close it. And you should be turning it counter clockwise if I'm not mistaken. Lefty loosey righty tighty lol. Just don't tighten it down too much and be careful because brass is a soft metal prone to distorting under too much pressure.

Anyway. It's been covered on here before along with pics.... something should turn up in a search for it on here. Otherwise somebody will come along and post a pic I'm sure...

Anyway.. good luck!