Hey guys I have a 1997 Ram 2500 with the 360, Auto Trans. I just replaced my water pump and got it all back together and I filled the radiator with coolant 50/50. I start the truck and let it run watching the temp and radiator, truck is at 200* and blows cold air now if I hold it at 2000 RPM it will blow warm air, so I ge out and I touch the bottom radiator hose its warm and the top radiator hose its COLD as hell.. ANy suggestions

 

Check your thermostat. If it's stuck closed, your coolant wont flow through the engine. Disconnect the upper radiator hose from where it joins the intake manifold and see if that thing looks rusted and worn out. You can test to see if it opens up by dropping it into a pot of boiling water. What you are looking for is movement and separation on the top section of the thermostat which would allow for fluid to pass from the lower section to the top through the gap that is created when the thermostat warms up. If that doesn't occur or you just feel like replacing the thermostat for shnitz and giggles. They only cost about 5 bucks. Stock temp is about 195 degrees lots of people recommend 180... Nothing wrong either way. 180 for slightly cooler operation temp, 195 for factory setup...

 

im sorry I forgot to mention I did put a new thermostat in when I did the w/p

 

I put a new stat in when I did the hughes plate, and it was bad straight out of the box... it happens..

i held it in my hand for about thirty seconds thinking "i should test this thing", but I didn't..

it was bad as proven by the test already mentioned.. the only thing I would add to that test is this: have teh stat already in the h20 while it's warming.. watch to see that it starts opening around the prescribed temperature.. several small bubbles for the 180 stat, more bubbles for the 195.. at a roaring boil it should be wide open.. pull it out with a utensil and watch it close.. drop it back in.. full cycle of that thing in other words..

you'd think those things would be bullet proof by now, huh?

oh, and make sure you have it in the right direction too.. that could be a problem as well..

 

by direction you mean the part with the point facing up towards the sky right?

 

yup... if memory serves correctly..

 

maybe drain the system, save the fluid if its clean, and try flushing the system with water to clear any debris out of the thing. Jam a rag and your hose into the top radiator hose to wash anything out that may have been stuck. Otherwise, maybe go to a radiator repair place to see if they can help.

 

Make sure you got the system full of coolant before you do anything else. Also, did you let it idle or drive it? I changed my radiator once, topped off with coolant with the heat on, and let the truck idle up to op temp. The heat blew cool air. As soon as I drove the truck, the heat blew hot. I assume I had air trapped in the heater core. I later topped off the rad after cool down and all was good.

 

how are you bleeding the coolant system?

this is how it should be done with our trucks, becuse this is a common problem

1. jack the front of the truck up, or up on ramps, so rad cap is higher than heater core (allowing it to burp)

2. Fill radiator until full

3. put the heat on FULL BLAST (defrost)

4. Start truck

5. allow it to run for a minute and then the coolant should drain down and then add accordingly.....



ive never had a problem with my cooling system nor my dads old ram (96 5.2 2wd)....give it a shot, i bet you'll have a different result

 

95RAM360: Thanks I will try this tonight. I work at a GM dealership and we have a Tech here who worked for Dodge for 16 years and he said that theres probably a BIG air pocket dodge's are famous for it he said to drive it around for a bit but im gonna try putting it up on ramps first