Renix still overheating...
Thread Starter
Junior Member
Joined: Jul 2013
Posts: 34
Likes: 0
From: springfield VA
Year: 1989
Model: Cherokee
Engine: renix
My 89 renix was over heating when i first drove it home. when i parked it i noticed a big puddle of antifreeze under the passenger side.
here is what has been replaced so far.
- checked coolant bottle for cracks (its good)
- replaced original cap with volvo (green cap)
- had the system flushed
when getting emissions done it failed ( dude swore it was the cat so he replaced it, it still failed and overheated )
when we put our hand on the Rad, it was pretty cold.
- so he replaced the rad with a "new" used one
- replaced the thermostat.
still overheating. the only thing now is it doesnt have a fan shroud. I know it makes a difference but ive had 4 xjs and 3 of them did not have fan shroud.
any input?
here is what has been replaced so far.
- checked coolant bottle for cracks (its good)
- replaced original cap with volvo (green cap)
- had the system flushed
when getting emissions done it failed ( dude swore it was the cat so he replaced it, it still failed and overheated )
when we put our hand on the Rad, it was pretty cold.
- so he replaced the rad with a "new" used one
- replaced the thermostat.
still overheating. the only thing now is it doesnt have a fan shroud. I know it makes a difference but ive had 4 xjs and 3 of them did not have fan shroud.
any input?
Thread Starter
Junior Member
Joined: Jul 2013
Posts: 34
Likes: 0
From: springfield VA
Year: 1989
Model: Cherokee
Engine: renix
I haven't seen the water pump.
I should have done the work myself but since it was already there and I needed it to pass emissions i let him work on it. Stupid mistake but I will get it back in the next couple of days and I will try to check out the water pump.
Thread Starter
Junior Member
Joined: Jul 2013
Posts: 34
Likes: 0
From: springfield VA
Year: 1989
Model: Cherokee
Engine: renix
So here is an update. the mechanic said he replaced the radiator, t-stat, and burped the system.
and he said it was still over heating.
today i went to pick it up, he said he added a shroud and it doesn't overheat anymore. kind of suspicious.
drove it home and temp stayed around 190:
after testing if for about 30 minutes of city driving it stay that way. I was at a red light looking at the light waiting for it to changed. when i looked back at the gauge, it had spiked up past the 260 mark. and slowly went down to 240 and the spiked down to 190...
so I got suspicious feeling , is there anyway the mechanic could have rigged the gauge to make it look like it doesnt over heat.
the fluctuation would happen when i am stopped ...
when i got home it was idling at 210:

when I turned it off, it climbed up to 250ish:

and when i turned the electrics on it went back down to 210,

what do you guys think, could it be the temp sensor, could the mechanic have scammed me ?
also when is the fan supposed to come on. it wasn't on when i was at 205.
cooling system looked clean and wasnt leaking coolant, and the coolant was flowing from what it saw.
and he said it was still over heating.
today i went to pick it up, he said he added a shroud and it doesn't overheat anymore. kind of suspicious.
drove it home and temp stayed around 190:

after testing if for about 30 minutes of city driving it stay that way. I was at a red light looking at the light waiting for it to changed. when i looked back at the gauge, it had spiked up past the 260 mark. and slowly went down to 240 and the spiked down to 190...
so I got suspicious feeling , is there anyway the mechanic could have rigged the gauge to make it look like it doesnt over heat.
the fluctuation would happen when i am stopped ...
when i got home it was idling at 210:

when I turned it off, it climbed up to 250ish:

and when i turned the electrics on it went back down to 210,

what do you guys think, could it be the temp sensor, could the mechanic have scammed me ?
also when is the fan supposed to come on. it wasn't on when i was at 205.
cooling system looked clean and wasnt leaking coolant, and the coolant was flowing from what it saw.
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Thread Starter
Junior Member
Joined: Jul 2013
Posts: 34
Likes: 0
From: springfield VA
Year: 1989
Model: Cherokee
Engine: renix
when its running at 200 i turn the heat on full blast and it drops 10-20 degrees.
when motors turn off they do heat soak which does cause an underhood temperature to increase. so that could be what your seeing.
with the heat on blast causing change i would still be weary about the thermostat
with the heat on blast causing change i would still be weary about the thermostat
Thread Starter
Junior Member
Joined: Jul 2013
Posts: 34
Likes: 0
From: springfield VA
Year: 1989
Model: Cherokee
Engine: renix
What he said. Check the water pump to, just replaced the one in my friends and the fins were completely rusted off.
Attachment 206150
Attachment 206150
but water is flowing through freely, and the thermostat is new, I just want to make sure that its not a gauge issue where i think everything is fine at 190-200 and its really at 260 or something crazy.
Senior Member
Joined: Mar 2013
Posts: 691
Likes: 2
From: Texas
Year: 1993
Model: Cherokee
Engine: 4.0L
When you turn the heater on, you are adding additional cooling fins to the system and the temp drops. This does not necessarily reflect on the condition of the thermostat which may or may not be defective, even if new.
You can fret and guess at gauge accuracy but the only way to tell what the system temperature actually is is to use an independent thermometer, the most efficient being an infrared unit.
I'm not sure about the Renix but the E-fan on later models comes on ~218*.
You can fret and guess at gauge accuracy but the only way to tell what the system temperature actually is is to use an independent thermometer, the most efficient being an infrared unit.
I'm not sure about the Renix but the E-fan on later models comes on ~218*.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,579
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
When you turn the heater on, you are adding additional cooling fins to the system and the temp drops. This does not necessarily reflect on the condition of the thermostat which may or may not be defective, even if new.
You can fret and guess at gauge accuracy but the only way to tell what the system temperature actually is is to use an independent thermometer, the most efficient being an infrared unit.
I'm not sure about the Renix but the E-fan on later models comes on ~218*.
You can fret and guess at gauge accuracy but the only way to tell what the system temperature actually is is to use an independent thermometer, the most efficient being an infrared unit.
I'm not sure about the Renix but the E-fan on later models comes on ~218*.
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
So here is an update. the mechanic said he replaced the radiator, t-stat, and burped the system.
and he said it was still over heating.
today i went to pick it up, he said he added a shroud and it doesn't overheat anymore. kind of suspicious.
drove it home and temp stayed around 190:
after testing if for about 30 minutes of city driving it stay that way. I was at a red light looking at the light waiting for it to changed. when i looked back at the gauge, it had spiked up past the 260 mark. and slowly went down to 240 and the spiked down to 190...
so I got suspicious feeling , is there anyway the mechanic could have rigged the gauge to make it look like it doesnt over heat.
the fluctuation would happen when i am stopped ...
when i got home it was idling at 210:

when I turned it off, it climbed up to 250ish:

and when i turned the electrics on it went back down to 210,

what do you guys think, could it be the temp sensor, could the mechanic have scammed me ?
also when is the fan supposed to come on. it wasn't on when i was at 205.
cooling system looked clean and wasnt leaking coolant, and the coolant was flowing from what it saw.
and he said it was still over heating.
today i went to pick it up, he said he added a shroud and it doesn't overheat anymore. kind of suspicious.
drove it home and temp stayed around 190:

after testing if for about 30 minutes of city driving it stay that way. I was at a red light looking at the light waiting for it to changed. when i looked back at the gauge, it had spiked up past the 260 mark. and slowly went down to 240 and the spiked down to 190...
so I got suspicious feeling , is there anyway the mechanic could have rigged the gauge to make it look like it doesnt over heat.
the fluctuation would happen when i am stopped ...
when i got home it was idling at 210:

when I turned it off, it climbed up to 250ish:

and when i turned the electrics on it went back down to 210,

what do you guys think, could it be the temp sensor, could the mechanic have scammed me ?
also when is the fan supposed to come on. it wasn't on when i was at 205.
cooling system looked clean and wasnt leaking coolant, and the coolant was flowing from what it saw.



