Radiator question

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Yep, it's in the wagon in my avatar. It's got a '74 225 3-speed.
 
williaml said:
I am in complete agreement. Last week motoring around town for about 15 miles the top of the radiator was 194 the stat housing 192 and the bottom hose 130 then yesterday the stat housing was 220 the hose into the radiator was 195 and the bottom hose was 130 it was hot out yesterday but I don't think that had much to do with it
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If the lower hose is 130* when the engine was at 190 and at 220,, the rads doing it's job, losing heat..

I'd look elsewhere,, changing the thermostat first, or temporarily removing it as a test.. check the bottom hose has a coil in it,, and not sucking shut as engine rpm increases.. jmo
 
inertia said:
If the lower hose is 130* when the engine was at 190 and at 220,, the rads doing it's job, losing heat..

I'd look elsewhere,, changing the thermostat first, or temporarily removing it as a test.. check the bottom hose has a coil in it,, and not sucking shut as engine rpm increases.. jmo
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Yes. Never overlook the basics. A bad radiator cap can cause overheating and boil over. Mine did yesterday because the filler neck was broken. 15# of pressure raises the boiling point another 45°. (3° per pound of pressure)
 
I was thinking the same on the bottom hose I felt it yesterday and there's no spring in it, should there be one.
 
inertia said:
If the lower hose is 130* when the engine was at 190 and at 220,, the rads doing it's job, losing heat..
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True, but at what flow rate?
(that was my point)
If you have 130 degree coolant coming out of the radiator then why is a new rebuilt motor overheating just like it did before it was rebuilt? (Flow volume)

And yes it should have a spring in the bottom hose to keep it from collapsing with the suction from the water pump and shutting off your coolant flow at higher RPM's.
 
I ordered a temp gauge to install to see what this engine is running at. My worry is that the rebuilder missed something a the flow of water is restricted in the block or head. The gauge worked flawlessly with the 69 engine. The gauge even at long idle with go to right of gauge not pegged but close.
 
An old radiator guy showed me a quick test for flow on the radiator. When cool, remove lower hose. Put hand over bottom outlet. Fill with water. Pull hand off outlet quickly. If water comes out fast, there's no major blockage. Comes out lazy, there's an issue. My Dart was running hot. New aluminum radiator. I put 1/8 inch holes in the thermostat. Installed a spring in the bottom hose. Made a fan shroud. Runs cool at all times. Do you have a shroud?
 
It very well could be the water pump vane plate is spinning on the shaft.
That would also explain why the cooler fluid coming out of the radiator doesn't cool the engine down. (still a flow volume problem)
Has it ever been off and checked, and is it the same water pump as before the rebuild?
 
Different water pump for the rebuild, I've never had it off but just purchased a 8 fin water pump thinking it would move the water faster
 
williaml said:
The gauge even at long idle with go to right of gauge not pegged but close.
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You are not using your head. The infra red numbers you posted don't bear out what the gauge is saying.
 
The engine has a 195 thermostat however the service manual indicates a 170 thermostat, I think I will start there.
 
TrailBeast said:
It very well could be the water pump vane plate is spinning on the shaft.
That would also explain why the cooler fluid coming out of the radiator doesn't cool the engine down. (still a flow volume problem)
Has it ever been off and checked, and is it the same water pump as before the rebuild?
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It's not nec to remove the pump to check if the impellor is turning,, just bend up a tool similar to the picture,, and you can reach down the by-pass hose fitting and "hook" the impellor, turn the fan,, and check if it's secure to the shaft..

cheers..
 

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I thought the average difference in temp from the top & lower hose was normally 20-30 degrees.

OP is posting a 60-80 degree swing :scratch:



inertia said:
It's not nec to remove the pump to check if the impellor is turning,, just bend up a tool similar to the picture,, and you can reach down the by-pass hose fitting and "hook" the impellor, turn the fan,, and check if it's secure to the shaft..

cheers..
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Good info...Thanks
 
6pk2goDemon said:
I thought the average difference in temp from the top & lower hose was normally 20-30 degrees.

OP is posting a 60-80 degree swing :scratch:
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Over 40* would be ideal,, the temp diff would change with rad efficiency and ambient temp.. running temp controlled by thermostat..
 
inertia said:
It's not nec to remove the pump to check if the impellor is turning,, just bend up a tool similar to the picture,, and you can reach down the by-pass hose fitting and "hook" the impellor, turn the fan,, and check if it's secure to the shaft..

cheers..
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That's a cool idea...
 
6pk2goDemon said:
I thought the average difference in temp from the top & lower hose was normally 20-30 degrees.

OP is posting a 60-80 degree swing :scratch:





Good info...Thanks
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And THAT my good Woman is why I think it's a flow problem.
The coolant may be staying in the radiator long enough to get that cool instead of circulating it through the engine faster.

That is good info inertia, thank you.
Never occurred to me to check it that way, but sometimes the vanes are mostly gone from corrosion too, so it may not be a for sure factor.
Water pumps are so easy to pull it might be worth it.
 
Thanks to all, I will let you know how I make out after changing both the thermostat and water pump ...
 
The people that suggested using a non-contact thermometer I think are correct. You should use it too also check the water temp coming out of the engine and see if it is close to the opening temp of the thermostat. It may reach a few degrees (up to 10 or so) until it opens and the temp levels out. As the others stated-you should have about 20-30 degrees drop across the radiator. I believe the engine block is OK. I think it will be found as a faulty thermostat or the fins loose from the core of the coils.
 
I replaced the thermostat last night. I installed a 160 degree thermostat there was a 180 thermostat in there. I started and allowed to run with rad cap off I had my finger in rad to see when the thermostat opened and felt the warmer water / antifreeze mix. The thermostat housing registered 174-177 the bottom rad hose was 133-140 the top rad hose was around 170. I wanted to wait to install the new water pump until I get my auxiliary temp gauge from Amazon to see what temp the car is running at.

I can't thank everyone enough for reading and responding

Thank you
 
csmith said:
As the others stated-you should have about 20-30 degrees drop across the radiator. .
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I think you'll find 20 -30* diff at idle under no load, would be very close to overheating under load with high ambient temps. (summer).. unless it's a very small (4-cyl) engine

If you go shoot the temps of different cars you have access to (I did),, I'd be very surprised if you didn't find the average to be well over 50* difference on a well maintained or new car..

I shoot the actual rad fitting,, not the hoses,, they seem to squew the temps..

Go check it out,, find out for yourself,.. I'd be sendin the rad out for service with a 20* inlet/outlet difference..

that's been my experience

cheers
 
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