Hi there:

I've replaced the heater core in my 87 Fiero SE, and now I'd like to burp the coolant system.

There are several online descriptions of this that I've read, so I get the idea. But as I refill the thermostat housing and run the engine several times to get the fresh coolant into the system, eventually what level should the coolant come up to in the housing? I.e. should it still be below the thermostat, when I push it back in? Or would this leave air in? Should the thermostat be immersed?

Novice question, but thanks...

Get the back of the car slightly higher than the front. Pull the thermostat and fill the coolant to the top of the thermostat housing. Loosen the radiator cap enough so that air and coolant can leak out and let it until you start seeing coolant. Put the cap on both the radiator and the thermostat housing. Start and run the car for a few minutes. CAREFULLY loosen the radiator cap to let the pressure (if any) out and repeat the first process. Without the thermostat in place the coolant will flow freely and any air should get trapped in the highest point which should be the thermostat housing. When you can do this process without finding the thermostat housing low put the thermostat back in and you should be done. I’ve done it this way for years and I’ve never had a problem.

Thanks firejo24.

But I'm still not clear on how high the coolant should optimally be when filled, in the thermostat housing. The thermostat itself has a rubber lip, a gasket, so it seals down tight on the metal lip inside, seeming to indicate that the coolant should be under it. But doesn't this leave air still inside?

You fill the coolant level up so that the thermostat housing is full to the brim. When you stick the thermostat back in, it will spill a few drops but that's OK. If you do it any other way, you'll end up with air still in the system as you suggested.

see my cave, coolant fill in coolant section.
if done with cave directions then radiator and heater core will burp themselves.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

Bloozberry and theogre:

Thanks very much for clarifying this. I also read the instructions in theogre's cave.

Much appreciated...

Regards,

~W~