Inertia
Well-Known Member
Its possible to use a "tool" down the water pump by-pass fitting to hook, and feel if the impeller spins/sticks or has electrolysis missing vanes.
Cheers
Overheating issues
- Thread starter phaelax
- Start date
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Cheers
If the hoses collaps as it cools down that indicates either the rad cap is defective ( not allowing fluid back in from the overflow) or the overflow does not have a vent which it must have.
Inertia
Well-Known Member
The lower hose collapsing shows no spring in the lower hose.
During higher rpm, as the pump creates greater low pressure on the suction side of the pump, (try saying that twice), it can suck that lower hose shut, as you saw.
I use a chunk of stainless welding rod, or heavy piano wire to make a lower "spring/coil".
Rev it up higher rpm while hot, and check it out, might collapse right before your eyes .
Again, lol, good luck .
During higher rpm, as the pump creates greater low pressure on the suction side of the pump, (try saying that twice), it can suck that lower hose shut, as you saw.
I use a chunk of stainless welding rod, or heavy piano wire to make a lower "spring/coil".
Rev it up higher rpm while hot, and check it out, might collapse right before your eyes .
Again, lol, good luck .
Temp guns don't read well on shiny aluminum. Try spraying flat black on the places you want to check. You can wipe the paint back off with some lacquer thinner when your done. Hoses usually read cooler than metal surfaces.
Hey. Flex fan is problematic. As stated. Lower hose collapsing might be an issue. Water pump might be as well. Really need temp top and bottom to see what the drop in temp is. Tells you if Rad is cooling correctly. Myself, I would ditch the aluminum Rad for a Big block A body Mopar factory rad. Copper and brass. IF the Rad is not cooling. BUT the flex fan for sure should be replaced....in any case. IMO. Could be timing, or Carb running lean.
Inertia
Well-Known Member
I read and understand that, and agree with your conclusion the cap could be bad.
I didn't see where he mentioned he specifically looked when hot and revved, thot I would mention it, cuz the collapsed hose will open as soon as the revs drop.
When he gets the inlet/outlet readings hot, he just might rev it, see the hose collapse, and perhaps have found the issue right there and then .
Thnx .
EDIT
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Check the simple stuff first. Remove the radiator cap. The coolant level should be up to the top of the radiator cap. The cap should have two rubber seals. The small rubber hose should be tight and free of cracks. The recovery tank should be about one-quarter full. Check for gunk on the bottom of the recovery tank.
Was there ever Dexcool in the system?
Was there ever Dexcool in the system?
This is incorrect. The coolant level should be about an inch or so down from the top of the fill spout. This gives room for expansion. If it's too full, it'll only push it out of the radiator cap relief valve.
That is true if you do not run a overflow bottle / recovery system what ever you want to call it.
(For the record I run a pressurized open system with an inch to the cap, no overflow bottle and have never dropped a drop of coolant)
The op IS running an overflow so the coolant should be 100% full and about 1/4 full in the overflow.
The overflow MUST have a vent so as the coolant heats and it's volume gets larger (ideal gas law PV=nRT) it goes into the overflow and the air above the 1/4 full overflow can be pushed out of the overflow bottle.
At temp the overflow might be 3/4 full.
Then as the coolant cools, it's volume gets smaller and pulls coolant from the overflow bottle back into the radiator.
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Never see this mentioned, the heater core on a lot of our cars, my non A/C Dart for instance, is a small radiator that sheds heat constantly. The diverter door allows the heat to travel in or out of the car. It has no adjustable water valve. Just a possibility to add to the confusion.
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The air diverter in the heat only box only stops or allows air to flow over the heater core
It does not have a provision to shed the hot air out of the car.
Inertia
Well-Known Member
It does, - out the open windows .
Did it one summer in Sacramento.
Heater on high in +100* weather
Another clue supporting what a couple people mentioned above.
Whether using a Chrysler's vented cap or the other guys always pressurized, once the coolant is in the overflow or recovery tank, it should be at atmospheric pressure.
In other words, the overflow tank should be vented to atmosphere on these systems.
When the engine coolant starts to vaporize the radiator cap should build pressure - up to 16 lbs - in the system. This pressure increases the boiling point allowing the system to operate with mostly liquid coolant.
Bottom line.
From cold start, take the cap off of the radiator and watch the coolant flow behavior.
Should be no flow really visible but the pumpo will suck down the level.
When t-stat opens the flow will be very obvious and you'll know the pump is working.
Suspect the system is not holding pressure. Either the radiator cap has failed or leak somewhere.
The overflow should be vented. Vented with and overflow hose or equivalent is best.
Pump may have small diameter impeller which needs to be driven faster than the large impeller
You got me there
Here are some shots from a jeep grand Cherokee I rented last week and drove through the Mojave Desert.
2023 Jeep Grand Cherokee
203 deg thermostat.
100 to 117 deg oat
Climbing
Note the temp is 221.
But not a problem
More climb at slower speed.
2023 Jeep Grand Cherokee
203 deg thermostat.
Driving on the flat
100 to 117 deg oat
Climbing
Note the temp is 221.
But not a problem
More climb at slower speed.
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Upper hose is too high, it's above the top of the radiator acting like an upside down P-Trap blocking the flow of hot water into the radiator for cooling.
Heat Rises, then stops at the highest point.....
Needs to flow uphill on a gradual incline to the top tank of radiator.
Another picture on how not to route it:
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Heat Rises, then stops at the highest point.....
Needs to flow uphill on a gradual incline to the top tank of radiator.
Another picture on how not to route it:
☆☆☆☆☆
Interesting observation and could well be contributing. Good eye.
Inertia
Well-Known Member
What if it was a truck, with a taller rad, raise the engine ?
Yes, there was a pump housing to raise the pump, in extreme situations mohos, tandem dumps .
You want the radiator upper inlet higher than the incoming Radiator hose, so the taller radiator would be a good thing.
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Inertia
Well-Known Member
It's a centrifical pump, creates low pressure, sucks, not blows .
Proper inclined angle of upper radiator hose to top tank inlet.
Proper fan to shroud ^^^ spacing/positioning too.
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Proper fan to shroud ^^^ spacing/positioning too.
☆☆☆☆☆
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