My truck has been sitting for a couple months and I just started to drive it again recently. I have been smelling coolant but assumed it was a pinhole leak in my radiator getting worse. Well today the truck began pissing coolant from the serpentine belt area (covering the alternator and front of the engine) and subsequently overheated. I assumed it was the water pump and pulled over to let it cool and was going to try to make it about a mile to home. The truck heated up again and I pulled over again.

This time I turned the heater on, it blew cool air for about 30 seconds and then turned hot and the engine temp dropped instantly and I made it the rest of the way. The strange part is I turned the heater off and could not get the truck to overheat again and the temp held steady. This made me think stuck thermostat, but if that is the case where was all the coolant coming from and why the smell the past couple weeks?

 

looke at the t-stat housing is there coolant leaking around it is the intake wet around that area and if theres coolant crystalizing its been leaking for awhile and check the front area around the water pump they are know after sitting awhile to go bad

 

it vapour locked in your coolant system it happens every once and a while, when you turned the heater on you gave a place for the air to move and heating problem disappeared it should be fine now... i hope

 

That would be excellent if this is the case. If so where was the coolant coming from?

 

When mine was leaking it appeared to be from where the shaft goes into the pump housing. It only leaked every once in a while. For as cheap as a new water pump is and as easy as it was to replace I just swapped it out. IMHO if its leaking, swap in a new one.

 

if your water pump is leaking, change it, it will leave you stranded and its a stupid reason to be stranded if u knew it was leaking

 

Don't water pumps have weep holes?

I think they vent coolant when the seal on the bearing is compromised. Maybe, as was suggested, you had a vapor lock and it was forcing fluid out the weep hole due to higher than normal pressure.

 

i really do believe it was a vapour lock, u said that u didnt have heat for about 30 seconds did u hear water flowing in the heater core

 

the stock ram thermostat in some years has a tendency to crack the brass arms underneath the main steel body

the Magnum engine water pump impeller is steel and will corrode away in a
'termites look like they have been eating the metal'
look if the coolant mix is not kept exactly right.