I have been running just water in my coolant system while I fixed my overheating problem. Fixed.


Now I'm flushing the radiator, and there's suppose to be two drain ***** right? One under the radiator (driver's side) and one on the back of the engine block.


Well I found both, and drained just the one under the radiator initially. Then I filled it with coolant and ran it for a couple days until I had time to do a proper flush.

So today, I go to drain the coolant... drain **** under the radiator spews green. Good.

Drain **** on the block comes out clear water. How is this possible? I immediately stopped draining from this location because I didn't want to drain something that I couldn't refill.
Is it not the same system?? If so, how is it possible that the fluid coming out of the block wasn't also green? I mean, I guess I suppose the coolant hadn't made it all the way though... I didn't drive it but 50 miles. But it's Austin Summer; it's hot. Is there a separate reservoir for the engine line?

 

No, it's all connected. If there was water against that plug then there must be at least a little bit of a dead-ended flow path there. still it's hard to believe that it didn't turn green.