Antifreeze pushing back into overflow
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Model: Cherokee
Antifreeze pushing back into overflow
I have a 87 jeep Cherokee and when the blower motor is on it pushes anitfreeze back into the overflow it dosent do it when it's off so it's not a head gasket or cracked head
CF Veteran
Joined: Nov 2008
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From: Oak Harbor, WA.
Year: 1987
Model: Cherokee
Engine: 4.0 liter RENIX I-6, DIY Cold Air Intake, 2.5 FM Exhaust, 3 Core Radiator
....which basically means that it is fine for your Jeep to have coolant pushing into the pressure bottle.....so long as it is not overpressurizing like a balloon or overflowing and blowing water out of hose connections or anything like that.
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Model: Cherokee
Well it has never done this and the water is not hot but I had it about a quarter of the way full and when I would let it run with the blower motor on it filled all the way to the top and was kinda leaking around the top
CF Veteran
Joined: Nov 2008
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From: Oak Harbor, WA.
Year: 1987
Model: Cherokee
Engine: 4.0 liter RENIX I-6, DIY Cold Air Intake, 2.5 FM Exhaust, 3 Core Radiator
When you turn your heater on there is a valve that opens to let hot water go to your heater core. It also opens to let water to your pressure tank. You may just have a little trapped air in the system somewhere.
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From: Southeast, tx
Year: 1990
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Raise the rear of the jeep and take out the temperature sending unit. The sending unit is on the drivers side of the head toward the rear. BE SURE IT'S COOL!
CF Veteran
Joined: Nov 2008
Posts: 6,989
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From: Oak Harbor, WA.
Year: 1987
Model: Cherokee
Engine: 4.0 liter RENIX I-6, DIY Cold Air Intake, 2.5 FM Exhaust, 3 Core Radiator
Run it with the cap off the pressure tank adding water or letting water overflow as needed until you know it's at normal operating temperature. Make sure the heater is turned on. If your T-stat is working as advertised it should be fully open by this temp. Let it run for another 5 minutes with the coolant fully circulating in the system. Then, add or remove water from the pressure tank as needed to get it at the "hot" line. Replace cap and you're done.
CF Veteran
Joined: Nov 2008
Posts: 6,989
Likes: 4
From: Oak Harbor, WA.
Year: 1987
Model: Cherokee
Engine: 4.0 liter RENIX I-6, DIY Cold Air Intake, 2.5 FM Exhaust, 3 Core Radiator
Sounds like air bubbles blocking, or crud/rust blocking or possibly your T-stat is stuck shut.
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From: Maine
Year: 1999 Sport
Model: Cherokee
Engine: I6
Run it with the cap off the pressure tank adding water or letting water overflow as needed until you know it's at normal operating temperature. Make sure the heater is turned on. If your T-stat is working as advertised it should be fully open by this temp. Let it run for another 5 minutes with the coolant fully circulating in the system. Then, add or remove water from the pressure tank as needed to get it at the "hot" line. Replace cap and you're done.
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