Yet another overheating thread... but interesting
06-05-2016, 06:53 PM
#16
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Year: 1999
Model: Cherokee
Engine: 4.0
I'm NO pro mechanic but have been messing with vehicles/machinery for the past 30yrs here in Memphis are (HOT and H U M I D..) The first 15 or so was working on my machinery Up north.
Here, it's nothing for it to get 140* on the ramp/deck at full sun, and 110* with 100%humidity at 1am with not a drop of rain in sight..
Just went a round with my 96 4cyl that ran a bit hot and was in a line waiting at Burger King, looked down and it's at 240+ (electric fan relay pooped out..)
ENOUGH OF THIS, so I pulled the T stat housing and drilled 4- 3/32" holes around the skirt of the Thermostat. (or you could push the spring back in and put a BB Pellet to block the shaft of the springs way to keep it open continuously)
NOW it runs at about 185 while driving/moving and only have to turn the fan on when I'm sitting.
Then, after a week decided to do same to my son's '01 Cherokee.
6cyl doesn't give the room for a cordless drill like the 4cyl does. So just pulled the T stat and got another.
Well, found out they come in 160*!! got one and a gasket, STILL drilled a couple holes, filled the system, and with the air on it stays around 195, or the mark before 210.. Never understood why they run SOO HOT and Jeep never really dealt with the issue.a
back in the day I would bypass the thermosensors on all my Honda's so the fan would be on with the key.
Just make sure to 'burp' the air from the system. AND take the bolts to a wire wheel and then put anti-seize on them before re-installing in head. Or heavy grease.
Granted, both my 4cyl and Sons' had new radiators installed but that was way BEFORE it was getting warm down here.
Errol
Here, it's nothing for it to get 140* on the ramp/deck at full sun, and 110* with 100%humidity at 1am with not a drop of rain in sight..
Just went a round with my 96 4cyl that ran a bit hot and was in a line waiting at Burger King, looked down and it's at 240+ (electric fan relay pooped out..)
ENOUGH OF THIS, so I pulled the T stat housing and drilled 4- 3/32" holes around the skirt of the Thermostat. (or you could push the spring back in and put a BB Pellet to block the shaft of the springs way to keep it open continuously)
NOW it runs at about 185 while driving/moving and only have to turn the fan on when I'm sitting.
Then, after a week decided to do same to my son's '01 Cherokee.
6cyl doesn't give the room for a cordless drill like the 4cyl does. So just pulled the T stat and got another.
Well, found out they come in 160*!! got one and a gasket, STILL drilled a couple holes, filled the system, and with the air on it stays around 195, or the mark before 210.. Never understood why they run SOO HOT and Jeep never really dealt with the issue.a
back in the day I would bypass the thermosensors on all my Honda's so the fan would be on with the key.
Just make sure to 'burp' the air from the system. AND take the bolts to a wire wheel and then put anti-seize on them before re-installing in head. Or heavy grease.
Granted, both my 4cyl and Sons' had new radiators installed but that was way BEFORE it was getting warm down here.
Errol
06-05-2016, 07:19 PM
#17
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Year: 1992
Model: Cherokee
Engine: 4.0L H.O.
The thermostat doesn't just let hot water out of the engine, it also gives the coolant in the radiator time to cool down. Low temp thermostat(or drilling) both prevents the radiator from doing it's job, and doesn't allow the engine to operate in its proper temp range.
06-05-2016, 07:22 PM
#18
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Year: 1999
Model: Cherokee
Engine: 4.0L
The temp here today was 113 and my xj ran at 200 on a manual t stat with the a/c on just going around town. It very seldom gets over 210. E fan kicks on with a/c, when a/c not on neither is the e fan. It will run about 190 with no a/c.
06-06-2016, 06:59 AM
#19
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Year: 1995
Model: Cherokee
Engine: 4.0 I6
Thanks for all the responses! Replaced Fan shroud as well as fan clutch with still no luck also got the aux fan to work properly. my thoughts are something may be blocked in the coolant passage way but IDK! this is becoming a pita the last thing i want to do is take it to a mechanic
06-06-2016, 07:14 AM
#20
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Try this flushing procedure:
THANKS to djb383:
"Remove the top radiator hose and top heater hose from the t-stat cover. Remove the bottom radiator hose from the water pump (very easy if the plastic air filter box is removed 1st). Stick a garden hose in the heater hose and flush. Stick the garden hose on the heater hose nipple on the thermostat cover and flush. Stick garden hose in the top radiator hose and flush. All areas are now flushed without crud moving from one place and lodging in another."
THANKS to djb383:
"Remove the top radiator hose and top heater hose from the t-stat cover. Remove the bottom radiator hose from the water pump (very easy if the plastic air filter box is removed 1st). Stick a garden hose in the heater hose and flush. Stick the garden hose on the heater hose nipple on the thermostat cover and flush. Stick garden hose in the top radiator hose and flush. All areas are now flushed without crud moving from one place and lodging in another."
06-06-2016, 07:37 AM
#21
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Year: 1999
Model: Cherokee
Engine: 4.0L
Try this flushing procedure:
THANKS to djb383:
"Remove the top radiator hose and top heater hose from the t-stat cover. Remove the bottom radiator hose from the water pump (very easy if the plastic air filter box is removed 1st). Stick a garden hose in the heater hose and flush. Stick the garden hose on the heater hose nipple on the thermostat cover and flush. Stick garden hose in the top radiator hose and flush. All areas are now flushed without crud moving from one place and lodging in another."
THANKS to djb383:
"Remove the top radiator hose and top heater hose from the t-stat cover. Remove the bottom radiator hose from the water pump (very easy if the plastic air filter box is removed 1st). Stick a garden hose in the heater hose and flush. Stick the garden hose on the heater hose nipple on the thermostat cover and flush. Stick garden hose in the top radiator hose and flush. All areas are now flushed without crud moving from one place and lodging in another."
06-06-2016, 07:52 AM
#22
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Year: 1995
Model: Cherokee
Engine: 4.0 I6
The radiator is brand new
06-06-2016, 07:58 AM
#23
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Year: 1999
Model: Cherokee
Engine: 4.0L
I was just pointing out that a radiator needs backflushing. A heater core needs backflushing as well. It is kind of like the filter that goes in your dryer. The air(water) flows in one direction all the time. By reversing the flow it pushes the lint(crud) backwards and loosens it up.
06-06-2016, 07:58 AM
#24
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If flushing from either way with a garden hose won't remove the blockage it's to the shop time.
06-06-2016, 08:01 AM
#26
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There's a drain plug on the side of the block below the exhaust manifold but I couldn't remove mine. Might try yours.
https://www.cherokeeforum.com/f2/rep...-block-124102/
https://www.cherokeeforum.com/f2/rep...-block-124102/
Last edited by EZEARL; 06-06-2016 at 08:15 AM.
06-06-2016, 08:13 AM
#28
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Year: 1999
Model: Cherokee
Engine: 4.0L
I also use a product sold by NAPA called NAPA Kool. It is a scale corrosion inhibitor made for class 8 diesel engines that I swear by. I have used it since they first started selling it. The directions are one pint to every 4 gallons of cooling system capacity as the initial treatment, then every 1 pint to 20 gallons every 10 to 12,000 miles. This translates to 12oz. initial treatment and 4oz. every 10 to 12,000 miles.
06-06-2016, 08:25 AM
#29
CF Veteran
After doing all the work and parts replacement you've done you really should verify the actual temp at the thermostat housing. If your driving it go to your local parts store. They should do it for you.
06-06-2016, 08:27 AM
#30
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I also use a product sold by NAPA called NAPA Kool. It is a scale corrosion inhibitor made for class 8 diesel engines that I swear by. I have used it since they first started selling it. The directions are one pint to every 4 gallons of cooling system capacity as the initial treatment, then every 1 pint to 20 gallons every 10 to 12,000 miles. This translates to 12oz. initial treatment and 4oz. every 10 to 12,000 miles.
Good stuff. Never had to use it in my personal vehicles but we used it at the shop in our trucks and hvy equipment.