I've spent the last month trying to dianose a leaking coolant system and finally figured out what the source of the problem was. I replaced my radiator hoses on 2005 MCS w/ Alta ones and I suspected that somehow my radiator hoses were leaking coolant as my resevior would be empty almost every other day, although nothing was visible leaking from the front end.

I poked around the rest of the engine bay over the weekend and found a lot of coolant sprayed all over farther back, behind the engine bay. One hose in particular had green crud all over it and was dripping slightly. I pressed on the hose and coolant would spray out! It looks like there is two pinhole sized punctures in the hose!! Its the hose connected to the water pump on the block, I think one goes to the reservoir, not sure where the other goes.

I've never touched these hoses before, so I'm wondering if this is just a case of bad hoses failing or if anyone else has had this problem? The dealership looked and it and said both hoses coming off the water pump are pierced and they're replacing it under warranty

Pic of the hose. You can't see the hole unless you bend it, but the wet spot is where its at.

 

that's not the heat exchanger in the back by the oil filter?