Is it possible for a waterpump to fail without exhibiting the obvious, ie: leaking from weephole or bearing shot? When I remove my radcap, the coolant doesn't seem to be moving. Just replaced the rad and T-stat. The strange thing to me is that the lower rad hose barely gets warm, in fact that whole side of the rad hardly warms up, while the other side and upper hose gets very hot. Seems to me the waterpump isn't sucking up the coolant at the bottom. No leaks from weephole or anywhere. Truck has a bit over 300,000 KM on it, and its still a strong runner.
Any input much appreciated.

 

There's a long spring in the lower hose that keeps the hose stiff and free flowing. It's possible that it's missing... just a thought.

 

Maybe try some type pf T setup in one of the hoses you are concered about. Then see if there is any pressure off the line on the T....

Something could be clogged and restricting flow..... I would want to isolate that component.

Just a thought... good luck!!!

 

I have seen water pump impellers completely rotted away from lack of cooling sys. maintenance, without leaking or noisy bearing...they've all been Fords tho, Taurus, Sable, Windstar...

 

The stamped steel impellor in the Magnum series engines can be 'eaten away' by cavitation bubbles, especially if the wrong antifreeze is used.

==
{from Bob Weber's column in CarConnection or Chicago Tribune
--
Colorful coolants

My '97 Dodge Dakota has ethylene-glycol (green) coolant. When I needed to buy
some coolant to top off the reservoir, I bought Havoline Dex-Cool (marked as
ethylene glycol). But this product is orange. Is the color difference
significant or is it okay for me to have a mixture of both in the radiator
system?

Although both are ethylene glycol based, Dex-Cool uses organic acid technology
(OAT) to protect the insides of the engine and radiator rather than the
silicates and phosphates often found in green coolants. I don't advise mixing
the two. Not only do they make an ugly brown when mixed, the benefits are
diminished. In fact, Chrysler has found that OAT coolants can lead to water
pump cavitation, especially in trucks with V-8 engines.

original at:
http://www.thecarconnection.com/inde...&sid=209&n=163

 

NO ORANGE STUFF FOR ME!!! WHOOPIE!!!!

 

DexCool should only be used in vehicles designed for it. Chevy found out the hard way that DexCool ate through some of the components of the 1997 and later S-10 Series vehicles. There was a big lawsuit where Chevy had to admit fault. My Cavalier has DexCool in it and all is well. I think I heard some stories of people putting it in their Chryslers and the same thing happened -- eaten/rotted internals. If you mix the two, which I suspect happened in my Ram, you get sludge build-up and the engine turns to ****.

 

from a cold start, fire up the motor and feel the upper hose. It should be cold and you should not feel any coolant flowing thru it. let it idle for a few minutes checking the upper hose, it should begin to get warm as the motor warms up. if it doesnt, then your t-stat is not opening up.

normal operation is your upper hose will be hot as hot coolant flow's out of the motor, and the lower hose will be warm. if your upper hose is hot and lower hose is warm you should be fine.

what brought this question on anyway, are you overheating? if so under what coniditions?

 

Thanks for all the replies. What led me to believe my waterpump may be iffy is that I was towing up a long steep hill and developed a leak from the T-stat housing. After it cooled down, the leak stopped, but the truck then wouldn't warm up, so I knew I needed a new T-stat. Got it home and backflushed the system and then discovered leaks in the rad, so I replaced that with a new one. After everything was back together I noticed that the coolant didn't seem to be flowing, from what I could see by looking down the filler. I drove it around and let it warm up, then removed the cap and there was no pressure behind it, so I replaced that as well, and thats when I started checking hoses, and discovered the lower rad hose was cold.
The truck never actually overheated, it warmed up to about 110 deg C on that long hill, but generally runs at about 90 deg C. at hiway speeds. I've only had the truck a short time, so I'm not sure if those temps are normal. Should it be running cooler?
BTW, the spring inside the lower hose is still intact.

 

sounds like you still have a leak. get a pressure tester to verify your cooling system will hold pressure... 16 psi IIRC. I would think that if you replace the t-stat and the upper hose warms up, your pump is working. if it wasnt, your upper hose would never get hot because the coolant would not flow thru it. at this point, i'd make sure the cooling system will hold pressure. if it does, then you should be fine. the t-stat is a know leak spot on the cooling system. make sure you use a dodge gasket next time around. it has built in sealant and is a snap to put down.

if your next hill climb results in temps climbing, i'd look at the fan clutch.