2002 Chevrolet Blazer

Engine Cooling problem
2002 Chevy Blazer 6 cyl Four Wheel Drive Automatic 100000 miles

My 2002 Chevy Blazer started overheating a few months ago. Temp would go up, and then come back down suddenly. Also, the system tends to lose coolant. I don't think any gaskets are blown (yet), but the coolant reservior is where I think the problem may lie. Can't find any pictures or diagrams anywhere to confirm, but here's the situation. On the front of the reservior is a hose that is attached to the radiator cap (I understand this is where the overheated coolant spills into the reservior). There is one other hose connection on the reservior - and it is not attached to anything. Is this supposed to be the hose that returns the cooled coolant back to the radiator? I can't find anything for it to plug into, but from where it lays, it just leaks out coolant. I attached a picture - the red circle is where the hose originates on the reservoir - the green circle is the open end. Where does it belong?

Also, this was originally a Dex Cool vehicle. Is there any problem with flushing the system, then using traditional coolant as opposed to that stuff?
October 5, 2008.

You can use universal green coolnat in it and you shouldnt have any problems. The extra hose is simply a drain for when the resevoir is too full so it doesnt blow the lid off it. It should go down in the fender where it can drain without geting anything under the hood wet

Oct 6, 2008.
After finding this Q & A, I think I may be headed down the wrong path. I connected the "extra hose" mentioned in this post to the hose that is located in the upper right corner of the picture in my post. I think this hose in my picture is from the secondary air injection system. Based on this post, it doesn't sound like they should mate. Can you please help clarify where this tube from this air injection system should be connected to?

Nov 16, 2008.