changing coolant expansion tank - help screwed up!
I am amidst changing the coolant expansion tank and oil filter housing gasket and could use some advice/wisdom.
When I pulled up and popped out the coolant expansion tank, I discovered that a part on the base where the expansion tank plugs into on the bottom was broken. So a few questions:
1) What does the coolant expansion tank plug into? something that is directly attached to the radiator, or some other intermediate coupling piece?
2) What broke was a black plastic cylinder piece that kept a spring in place that was pushing against a metal cylinder. It kind of looked like some sort of thermostat. What is this and how important is it?
Sooo, i couldnt plug the new expansion tank in, so I took out the spring. That enabled me to push the broken plastic cylinder piece back into the base and attach the expansion tank. I really couldn't figure out what function the spring did.
How badly did I screw this up? Can I drive this thing for a while, at least until I get a replacement radiator or whatever is broken?
Also, I had trouble getting to the engine block drain bolt. I have genuine BMW coolant ready to go, but the old stuff was orange colored. Am I asking for trouble by topping it up with the BMW stuff?
Thanks for any help.