Ok, so I was thinking about how to solve the air in the cooling system problem in my 3.4l. I took a look at the z28 thermostat housing and realized it has the same mount, so it would bolt right up. So since it has the bleeder valve on it, I could use that and take care of the air in the system finally. I noticed the z28 thermostat housing is flat on top, probably from the way the engine was designed. So I know the thermostat has to be changed out as well to compensate for that flat area.

I looked at the thermostat of the z28 compared to my 3.4l. (online, I havent tested it out yet) I noticed the z28 thermostat goes down into the block farther, basically taller on the bottom end of it.

I was wondering if that taller portion would still sink down into my block as well?
If so, and I installed it, would it still work properly?

 

I guess nobody has really tried this one yet and Im going to have to find out on my own huh? haha

 

well i guess ill just try picking up a thermostat this weekend and see how it fits. ill hold off on the housing until i see how the thermostat works. Ill update after I figure everything out in case anyone else is interested since no one has done this before apparently.

 

Get a thermostat that has a small bleed hole in the flange. If you can't find one, then make your own by drilling a 1/16" hole through the flange.

 

lt1 is reverse flow so the thermostat is backwards. wont work in a 3.4

 

Ah, gotcha. Thats what Ii was afraid of. Thanks craby.

And I guess I will take your advice then 69 and make a hole, and put in a bleeder on my thermostat housing.

Considering the flow is reversed, is the procedure for bleeding different, or can I still go about it the same way?

 

Air should not get trapped in your system. If you keep getting air in the system then there is a reason. Figuring out WHY you have air in your system should be the focus.

In a normal system it should take three thermo cycles to remove all the air. You heat the car up and let it cool back down without driving it. Don't even rev it. That will purge a system, unless there is a point in the system that is higher than the rad cap. When a car is designed with a "HIGH" point the factory will install a bleader. If you don't have one you don't need one.

If you keep getting air your system it is drawing the air in cold or something like a headgasket is putting the air in.

Back in the day some of the Vetts did not like to bleed because of the bends in the hoses. A little help from a jack (jack the front of the car up) gave us some positive rake but even letting the car heat cycle while sitting point up a hill could help if the issue is trully trapped air.

 

Thats the problem and actually another concern of mine. The radiator cap is one of the lower things in the car. The highest point on these are in a couple spots. The thermostat housing being one. Intake cooling lines being another. And the flat hoses coming from the heater core are the next. All higher than the rad cap by a significant amount. Even jacking up the car doesnt set them lower. Id need a shop lift to lift just the front up high enough to make it the highest point.

Also, my thermostat keeps sticking shut. Ive gone through 3 of these things already. The coolant is clean and clear and green of course. All the other hoses are hot, except the one going to the thermostat housing which tells me, it isnt opening. Could air in the system screw them up?
Another hint is that the coolant from the engine/heater core builds up and purges out of my coolant tank instead of flowing back through the radiator and through the thermostat back into the engine. I dont think the radiator is clogged either because I would imagine the hose going to the thermostat would be spongy instead of firm then. I could be wrong. Hence why Im asking.

Ive never had such a headache with the cooling system as I do in this camaro for some reason. Then again, in the last one, I replaced everything all at once. I dont have the money for it this time around.

Sorry if Im typing a lot, Im just trying to be as detailed and accurate as possible.

 

have you done a pressure test?

 

Sounds to me like something is pushing air into your system. How can it be a basic design issue if you are the only one with the problem?