Driving on the highway yesterday the upper radiator hose decided to slip back off the radiator and dump 2 gallons of coolant on the side of I-88. The hose is in good shape, and as far I knew tight. So I popped it back on, tightened it down, added water and drove home on surface streets. Gauge was reading like 210 but it has been like that since I replaced the sending unit months ago, I just didn't think it was right but now I'm not so sure.

Did a more in depth look over my cooling system (pump, thermostat, hoses, belt, fan clutch are all under a year old). One trick I always knew to test pump flow was to squeeze the upper hose and feel if water rushed back through. Well I can't squeeze the hose, its rock solid. Another thing that worries me is the the left side of the radiator gets hot, too hot to touch, where the right side (output side) feels cool, just barely warm. I know my Ram came with 'heavy duty cooling' but I feel like that's too cold. So blocked radiator or something?

Wanted to know what you guys thought and any input on the stiff upper hose from both the v8s and the v10 guys, maybe it's normal, I don't know, I don't think I had ever been able to pinch the upper hose at all when hot.

 

Definitely reads like an obstruction. I've been able to pinch my upper rad hose when running. It's the original radiator right?

 

Depending on how long the engine has been running, the radiator hoses WILL get hard. The system builds pressure as it warms up. (higher pressure means higher boiling point, lower freezing point.) So, if the cap was on, and engine nice and toasty warm, hard hoses are normal.

As for the inlet side being to hot to touch, well... it IS 200 and some change degrees.... I wouldn't wanna lay hands on that either.... barely warm on the output side is a GOOD thing. That is what you WANT to happen. It IS the radiators job to dissipate heat after all.

As for apparently running a bit hot.... get a cheap IR thermometer, and see what temps are really like in various places. (will tell you how accurate your gauge is too.) You may have an air bubble in there somewhere.....

Also, the hoses shouldn't become rock hard right away..... (nor should they blow off the radiator.....) As a test, let the truck cool completely. Feel your hoses. Should be relatively soft. Start the engine. Is the hose now suddenly rock hard? If it is, you got a bad head gasket somewhere. (that would build rather high pressure quickly, and may also explain why the upper hose blew off.)

 

I do not think it is the original radiator. My understanding is the V10s came with a copper core radiator and this one is aluminum.

Ok, so the hose is soft and malleable when cool, and stays the same after starting the engine and remains so till the thermostat opens up, then it get hard.

I have an IR thermometer that I will be able to use tonight so I'll check that out and report back with what I find. I know the radiator should be cooler on one side, since it does dissipate heat to the air as the coolant moves across it, I guess I was just surprised at how cool it was. But then again, it's not like I checked the temp before now nor should I expect an engine this big to not need that cool of water going back into it.

I'll keep at it and let you guys know what I find, thanks for the input as always!

 

My truck has an aluminum radiator that looks original and a 180 t-stat. I checked it after a ride today and it's just as you reported. The top hose is firm after the t-stat opens and you can feel a difference in temp from one side to the other. So far I've never had a problem with over heating, though it'll get pretty warm when towing in humid weather. I service the cooling system every 2 years and refill it with the dodge coolant.

 

Thanks for the response Jimy, good to know it seems normal.

Got some numbers from the IR thermometer and a pic to share.

Temps are as follows for the front of the cooling system
Thermostat Housing - 180*F - 185*F
Upper Radiator Hose - 170*F
Hot Side Tank of Radiator - 165*F
Cool Side Tank of Radiator - 85*F
Lower Radiator Hose - 85*-90*F

This is all the while while my gauge reads 205-210*F

And here is a picture of the upper inlet of the radiator where the hose popped off. It almost looks like it was intended for two different size hoses or something. The hose only fits on the lower, or larger shoulder of the fitting, there is no way I would be able to tighten the hose down enough for the higher, thinner fitting. I don't see how that can allow a smooth flow from hose to radiator...



What do you guys think?

 

So long as the hose seals on there good, you should be fine. Clamp should be south of the little ridge, so it helps hold things in place.

A minor restriction to flow isn't that big of a deal though, the pump moves plenty of coolant.

 

The top and bottom hose on mine are pretty big in diameter. They both fit on the outer shoulder. (not sure if my radiator has the 2 step thing or not.) I don't have an IR temp thingy, but my drivers side is noticeably hotter than the passenger side so your radiator temps look right to me.