over heating

[justtime520]

I have a 71 c10 327 with short water pump I just change the thermostat and water pump with new. now its over heating cant figure it out any help thanks

[justtime520]

and the top hose to the intake empty after i run it. and before it was full

[sneakysnake]

Was it overheating before?
Did you put the thermostat in with the spring side down?
Did you get a "newer" water pump that spins in the opposite direction.

[69halfton]

not trying to be insulting, or sarcastic..

but is there coolant in it?

..stranger things have happened... you and your friend put it together, and you have the classic case "i thought you put the oil in.." "..i thought YOU did"

Ive learned that the hard way

[justtime520]

the spring is down the water pump is new but for the same year of engine. i think this might be the problem, the heater is hooked up but does not work. if i route the water pump to heater hose back to the intake should that fix it

[justtime520]

yes also the heater hoses are burning hot as to the radiator hoses are barely warm

[Camper Power]

Originally Posted by justtime520

and the top hose to the intake empty after i run it. and before it was full

if that hose is empty when the engine is warm usually means 2 things, bad thermostat or low coolant, and since the thermostat is new, the best reason is that the coolant is low, open your rad cap when the truck is cool and check the level of the coolant, if it is hard to see you'll need to top it up. the hose may have had coolant in it before but chances are there was air in the system. but dont rule out the chance of having a faulty thermostat.

[spinning wheels]

Originally Posted by justtime520

I have a 71 c10 327 with short water pump I just change the thermostat and water pump with new. now its over heating cant figure it out any help thanks

What kind of gauge is reading the water temp?

I had a Stewart Warner, water temp gauge get stuck one time. I thought I had overheated. I pulled over and waited for a while. It seemed that the engine would not cool down. I tapped the gauge with my finger, damn thing dropped down to 120 degrees

You can bye pass the heater all together. I had to do that cause it looked like a green niagra falls under my dash, when the core leaked.

[sneakysnake]

Here is a basic sys.and direction flow.

[justtime520]

the gauge is good goes up to 220 and climbing. i going to bypass the heater and see if that works if it doesnt then i have the wrong pump

[sneakysnake]

Blocking off heater will tell you if the thermostat is opening.Looping the hose will cause the water to stay in the motor and not flow to the radiator.

[justtime520]

tried to block off the heater but hose are different sizes. may this changes it
it had a 180 thermostat and i put a 195. heres whats happening i start her up
and the radiator fluid rises. the heater hoses get hot while the radiator hoses stay warm. the top radiator hose is not filling even when radiator is full.

[justtime520]

and water pump is burning hot engine is warm

[sneakysnake]

Take the heater hoses loose from firewall, use a short 1/2 drive extension to plug the lines(male end small hose female large hose).
Take cap off radiator and start truck and see what the water does.When the thermostat opens you should see water flow,make sure its flowing in proper direction. If it doesnt open then check the thermostat.

[cdowns]

i think you have the thermo in backwards//i'd take the houseing off and check the thermostat it's about the only thing that it could be

[Boog]

I went through similar situation on an 85 a few years ago. I replaced the 180* stat with a 195* and the gauge went nuts. At an idle it would climb like that. After trying 2 more new 195* stats I put the 180* back in and it settled down and held steady.
Whether the heater hoses are hooked up to the heater or not won't make much difference in how cool the engine runs. Run the one hose back into the block if you want and coolant will still circulate through the radiator just fine.
By the way were you trying to cure a cooling problem or just replacing a leaky water pump?

[cdowns]

Originally Posted by sneakysnake

Blocking off heater will tell you if the thermostat is opening.Looping the hose will cause the water to stay in the motor and not flow to the radiator.

looping the heater hoses has nothing to do with circulation opf coolant thru the radiator

[justtime520]

Ok after forty times of draining the system i am putting the old thermo back in
and it goes springs down ho's up, it didnt over heat at all before and i had a small water pump leak. so i got a wild hair up my ass and decided to do the hole shabang

[sneakysnake]

Originally Posted by cdowns

looping the heater hoses has nothing to do with circulation opf coolant thru the radiator

Your right I was thinking the heater would show flow and keep you from telling if the thermostat was opening.....(unless the return goes back to the radiator like mine does)

[justtime520]

ok change thermostat same deal I called checkers and they are telling me its the right pump.

[Longhorn Man]

i say refill the rad, put the cap on, fire up the truck in the driveway, and watch it. If it is actually overheating, then you'll know.
If it is leaking out as much as it is low now, then you'll know.
But I think it'll be fine. It sounds like you had a hella air pocket in there.

[Boog]

Ok, just to recap here.
You put on a new water pump because the old one was leaking.
Replaced the thermo at same time just for good measure.
Now the temp gauge goes way up and there is no coolant coming back into the radiator from the upper rad hose.
Put old stat back in, filled with coolant and the same happens.

It sounds like possibly an air pocket preventing to coolant from moving up through the upper hose or the system is just still not full of coolant or there is something wrong with the new water pump. Something is blocking the flow somewhere.

One other suggestion is to remove the thermostat and pour coolant down into the manifold until full then replace the thermostat and hose. This might purge any remaining air in the engine.

When you fill the radiator do you start the engine and let it run a while until the coolant level drops down then add more? Or do you just fill it once and put the cap back on and think it's full? I know it may sound like a dumb ? but I don't know how much experience you have or if you are aware the coolant level will drop once it runs for a while. That's about all I can come up with for you.

[justtime520]

went and pulled the casting numbers for it and did a check and it is a similar pump but not the same, but they should still work. i am pretty sure there is air in put cant figure out how to get it out. i tried letting it sit on but it overheats to about 230 then i shut it off and it still climbs. i just dont know what to do iam stranded at my house away from the world

[justtime520]

i fill it up and nature take its course. but it runs for a couple of minutes until it reaches 230 and then i shut it down and the radiator is still at the top. the bottom radiator hose isnt even filling up while its running

[67ChevyRedneck]

Just tossing some ideas out...

Is the fan belt tight enough and turning the water pump?

Does your radiator cap and seal look like they are still in good condition?

What type of fan and fan shroud do you have on your motor? If you've been checking to see if the system works with the fan off, it will overheat.

Was it overheating before you started fixing stuff, or was it just leaking?

Does your lower radiator hose have a spring in it? Does it look like it's collapsing/closing when the truck is running?