Having this problem with both my 98 dc2 and 98 ek (y8)... Followed the service manuals for burping coolant, and even after an hour of burping (squeezing hoses, revving up, heater core open, etc...) I still cannot manage to get the air out (still bubbling). Cant find any leaks

Did a chemical block test on both cars, both passed... so there's no way the air can be a blown head gasket..

What are some possible reasons I cant get all the damn air out of both cars?

Edit: I have repeated this process for several days on the dc2 and driven over a hundred miles

 

Is it coolant or water in there?

 

I read nothing that rules out this possibility.

 

First, after capping the radiator and driving around in either vehicle, what makes you think there is still air in the cooling system ??? Second, you do realize that once the engine comes up to operating temperature, especially if you are running some type of anti-freeze, the fluid will begin to boil well before the 212' F point and this will create some bubbles... making it appear that you still have air in the system.

If you have a stable idle at all times, and you do not have an erratic fluctuating temperature gauge, I bet you are just fine and the cooling system is properly bled.

 

The chem test concludes the bubbles are not a result of a combustion leak. So at least a blown head gasket is probably not the reason I'm seeing bubbles.

Yeah I didn't think about the lack of pressure from the rad cap lowering the boil point of the coolant. My bad.. All these diy mechanics on YouTube are just saying "oh derp, wait until it no longer bubbles.."

Does running without the cap for extended periods of time do any damage? I mean, the reason the cooling system is pressurized is to increase the boiling point right? So wouldn't that mean you could create hot spots when idling without a cap for too long? Just wondering for future reference.

Thanks

 

Assuming that your block test was done correctly, which I am not inclined to do, you still would not have ruled out a blown head gasket, which is among the most complex of engine diagnoses.

 

What should be done to conclusively determine I dont have a blown head gasket? I guess it would be good to check.

 

do a compression test; followed by a leak down test.