I still havent fixed my vacuum leak, but thats not the point.

My motor just seems to keep eating up coolant, after a short drive I'm contantly having to fill up the overflow tank.

Theres no white exhaust, where the heck is the coolant going?

 

Onto the ground?

 

If it is not going onto the ground, and there is no white smoke on startup, then the only way to be absolutely sure is to do a coolant system pressure check.

 

I havent ever nseen any coolant o the ground, so I'll get a pressure check. Could the fact that I have a aftermarket radiator cap have anything to do with this? I've heard of them casuing problems before.

 

Use OEM caps. Did you properly bleed the system with heater in the car cranked all the way up? That will make it suck a lot of coolant out of the resivour if it wasnt done.