BIG overheating issue!
CF Veteran
Joined: Mar 2010
Posts: 47,923
Likes: 38
From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
Ok, maybe it's not a myth. I've been wrong before.....won't be 1st time, won't be last time either.
I just don't see how a non-positive displacement pump, like the water pump, can create a hose collapsing suction........flow yes, but not suction enough to collapse a hose. Doesn't the closed t-stat create blockage/stop flow? Doesn't the water pump have 2 intakes so that when the stat is closed (blocking flow to one intake) flow continues thru the pump, block and head thru the other coolant intake (the heater hose)? If the water pump could create a suction while the stat was closed, wouldn't the small heater hose (the other coolant intake) collapse as well (no spring in it) when the motor started up? For the moment I'm from Missouri the "show me" state......or explain how.
LOL
I just don't see how a non-positive displacement pump, like the water pump, can create a hose collapsing suction........flow yes, but not suction enough to collapse a hose. Doesn't the closed t-stat create blockage/stop flow? Doesn't the water pump have 2 intakes so that when the stat is closed (blocking flow to one intake) flow continues thru the pump, block and head thru the other coolant intake (the heater hose)? If the water pump could create a suction while the stat was closed, wouldn't the small heater hose (the other coolant intake) collapse as well (no spring in it) when the motor started up? For the moment I'm from Missouri the "show me" state......or explain how.
LOL
CF Veteran
Joined: Dec 2012
Posts: 4,169
Likes: 6
From: York, PA
Year: 1998
Model: Cherokee
Engine: 4.0
To the OP, are you sure the hose is the problem here? Any leaks or coolant loss otherwise?
CF Veteran
Joined: Mar 2010
Posts: 47,923
Likes: 38
From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
That article is in reference to a closed cooling system. The 98 Cherokee that the OP is talking about has an open system. It seems highly unlikely that this would be able to happen on a '98, and if it does, there's something else seriously wrong.
To the OP, are you sure the hose is the problem here? Any leaks or coolant loss otherwise?
To the OP, are you sure the hose is the problem here? Any leaks or coolant loss otherwise?
CF Veteran
Joined: Jul 2009
Posts: 1,640
Likes: 0
From: Keesler AFB, MS
Year: 1998 XJ
Model: Cherokee
Engine: 4.0L
UPDATE: Changed oil, im about to wrestle the lower radiator hose, will tell you how that goes. it's still leaking a little when running and im about to get some plugs and wires. wires were stuck on plug pretty well. i took it to autozone and it just had a CEL for misfires, nothing more. it also quit overheating. i drove it around town, got some fresh gas in it and it ran well when i got in it. 
CF Veteran
Joined: Jul 2009
Posts: 1,640
Likes: 0
From: Keesler AFB, MS
Year: 1998 XJ
Model: Cherokee
Engine: 4.0L
That article is in reference to a closed cooling system. The 98 Cherokee that the OP is talking about has an open system. It seems highly unlikely that this would be able to happen on a '98, and if it does, there's something else seriously wrong.
To the OP, are you sure the hose is the problem here? Any leaks or coolant loss otherwise?
CF Veteran
Joined: Dec 2012
Posts: 4,169
Likes: 6
From: York, PA
Year: 1998
Model: Cherokee
Engine: 4.0
I think my e-fan might also be toast but no overheating issues.
CF Veteran
Joined: Jul 2009
Posts: 1,640
Likes: 0
From: Keesler AFB, MS
Year: 1998 XJ
Model: Cherokee
Engine: 4.0L
Sure was, caused a chain reaction then the temp spiked to 260 and cracked my head in between the two valve seats above the #1 cylinder on the lower side of the head. Also had a crack in the same place on the #3 but I was not having any issues in that cylinder
CF Veteran
Joined: Dec 2012
Posts: 4,169
Likes: 6
From: York, PA
Year: 1998
Model: Cherokee
Engine: 4.0
Ouch. I can't believe I didn't blow my head/gasket when I blew a freeze plug. I drove at least 2 miles without any coolant, I thought she was gonna blow. Fixed the plugs, cleaned the intake real good and checked the oil and new coolant, and she runs like a champ now. I think any other engine would've blown under those conditions lol. I will have to keep an eye on my E-fan, and test it when I get a chance. What module/sensor is responsible for activating the fan?
CF Veteran
Joined: Jul 2009
Posts: 1,640
Likes: 0
From: Keesler AFB, MS
Year: 1998 XJ
Model: Cherokee
Engine: 4.0L
It wasn't a module/sensor for me. It was kicking on when it was suppose too. At first it was spinning fast but when it stayed on for a long period of time, it stopped spinning as fast not drawing in enough air. It's a one speed fan, should not slow down or speed up
CF Veteran
Joined: Nov 2009
Posts: 8,172
Likes: 17
From: The Republic of TEXAS
Year: 1998
Model: Cherokee
Engine: 4.0L HO
A faulty radiator cap on a "open type" cooling system can cause a hose to collapse......but only when the motor is off, has been off for a while, and has cooled substantially.
Thought we were talking about a water pump collapsing a hose which means the motor must be running vs a hose collapsing while the motor is off.
I've never seen a hose collapse when the motor is running.....again, how does a hose collapse when it's pressurized from with-in.
That goober that wrote/post that wiki.answer is far from the sharpest tool in the shed and needs to get his facts straight.....he obviously doesn't understand the difference between open and closed cooling systems......but I guess what he/she said must be true because they post it on the Internet.
Thought we were talking about a water pump collapsing a hose which means the motor must be running vs a hose collapsing while the motor is off.
I've never seen a hose collapse when the motor is running.....again, how does a hose collapse when it's pressurized from with-in.
That goober that wrote/post that wiki.answer is far from the sharpest tool in the shed and needs to get his facts straight.....he obviously doesn't understand the difference between open and closed cooling systems......but I guess what he/she said must be true because they post it on the Internet.
CF Veteran
Joined: Mar 2010
Posts: 47,923
Likes: 38
From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
CF Veteran
Joined: Nov 2009
Posts: 8,172
Likes: 17
From: The Republic of TEXAS
Year: 1998
Model: Cherokee
Engine: 4.0L HO
Let me put it like this....in a properly maintained, properly functioning cooling system (all components), no hoses should collapse. There will always be posts in whatever forum about this, that and the other malfunctioning for whatever reason.
I read about collapsing rad hose shortly after joining this forum but before we bought our XJ. So, after buying our XJ, we started routine maintenance including rad hose replacement. The old hose did not have a spring in it and after checking with 4 parts stores for a rad hose with a spring and not finding one, we installed a bottom rad hose that does not have a spring and all is still good. Again, hoses shouldn't collapse in properly funtioning cooling system....even when there's no spring.
I read about collapsing rad hose shortly after joining this forum but before we bought our XJ. So, after buying our XJ, we started routine maintenance including rad hose replacement. The old hose did not have a spring in it and after checking with 4 parts stores for a rad hose with a spring and not finding one, we installed a bottom rad hose that does not have a spring and all is still good. Again, hoses shouldn't collapse in properly funtioning cooling system....even when there's no spring.
Seasoned Member
Joined: Aug 2012
Posts: 288
Likes: 0
From: Amarillo, Texas
Year: 1992
Model: Cherokee
Engine: 4.0I
Let me put it like this....in a properly maintained, properly functioning cooling system (all components), no hoses should collapse. There will always be posts in whatever forum about this, that and the other malfunctioning for whatever reason.
I read about collapsing rad hose shortly after joining this forum but before we bought our XJ. So, after buying our XJ, we started routine maintenance including rad hose replacement. The old hose did not have a spring in it and after checking with 4 parts stores for a rad hose with a spring and not finding one, we installed a bottom rad hose that does not have a spring and all is still good. Again, hoses shouldn't collapse in properly funtioning cooling system....even when there's no spring.
I read about collapsing rad hose shortly after joining this forum but before we bought our XJ. So, after buying our XJ, we started routine maintenance including rad hose replacement. The old hose did not have a spring in it and after checking with 4 parts stores for a rad hose with a spring and not finding one, we installed a bottom rad hose that does not have a spring and all is still good. Again, hoses shouldn't collapse in properly funtioning cooling system....even when there's no spring.
CF Veteran
Joined: Mar 2010
Posts: 47,923
Likes: 38
From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
Let me put it like this....in a properly maintained, properly functioning cooling system (all components), no hoses should collapse. There will always be posts in whatever forum about this, that and the other malfunctioning for whatever reason.
I read about collapsing rad hose shortly after joining this forum but before we bought our XJ. So, after buying our XJ, we started routine maintenance including rad hose replacement. The old hose did not have a spring in it and after checking with 4 parts stores for a rad hose with a spring and not finding one, we installed a bottom rad hose that does not have a spring and all is still good. Again, hoses shouldn't collapse in properly funtioning cooling system....even when there's no spring.
I read about collapsing rad hose shortly after joining this forum but before we bought our XJ. So, after buying our XJ, we started routine maintenance including rad hose replacement. The old hose did not have a spring in it and after checking with 4 parts stores for a rad hose with a spring and not finding one, we installed a bottom rad hose that does not have a spring and all is still good. Again, hoses shouldn't collapse in properly funtioning cooling system....even when there's no spring.
CF Veteran
Joined: Jul 2009
Posts: 1,640
Likes: 0
From: Keesler AFB, MS
Year: 1998 XJ
Model: Cherokee
Engine: 4.0L
I Could have had a possible bad radiator cap ultimately causing the hose to collapse. When I had my issue, I took the advice from everyone on this forum and changed what they advised. I posted the chain of events that happened to me, if its an uncommon occurrence, I am glad I got to witness it and share my experience and advice with others. I could have possibly never understood the cooling system entirely and blamed it on the faulty Efan, when the root of the problem was a radiator cap. Whatever it was, the lower radiator hose collapsed while the engine was running and shot the temp up to 260+ cracking my head. Point is catch the small problems before they suddenly become big problems