how hot is too hot
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
I never worry about mine unless it is in the red. You will know if you have a problem because these engines run so hot, it will shoot straight from normal temp. to the red if you have a cooling system issue.
CF Veteran
Joined: Feb 2010
Posts: 12,367
Likes: 23
From: Oroville, CA
Year: 1995
Model: Grand Cherokee
Engine: 4.0 with all of the noise and clatter
I beg to differ....first hand experience. My brothers 93 wrangler ran bout 225°(highway) and the ONLY thing he did was swap tstats and it runs bout 215(highway)...and he changef it between two 100°+ days.have you actually tried it or are you going off what you were told or read.
Senior Member
Joined: Nov 2009
Posts: 904
Likes: 3
From: Maine
Year: 1999 Sport
Model: Cherokee
Engine: I6
Mine NEVER goes above 210. EVER! The boiling point of water is 212, so I think anything over 210 is too hot. Try changing out your coolant and put some nice, new, clean stuff in her.
Seasoned Member
Joined: Jun 2011
Posts: 273
Likes: 0
From: Pensacola Fl.
Model: Cherokee
Engine: 4.0
CF Veteran
Joined: Nov 2009
Posts: 8,172
Likes: 17
From: The Republic of TEXAS
Year: 1998
Model: Cherokee
Engine: 4.0L HO
CF Veteran
Joined: Jun 2011
Posts: 2,460
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From: Dayton, Ohio
Year: 1992
Model: Comanche
Engine: 4.0
Originally Posted by bigvig
Mine NEVER goes above 210. EVER! The boiling point of water is 212, so I think anything over 210 is too hot. Try changing out your coolant and put some nice, new, clean stuff in her.
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Senior Member
Joined: Nov 2009
Posts: 904
Likes: 3
From: Maine
Year: 1999 Sport
Model: Cherokee
Engine: I6
Actually, I lie. Last week I blew the heater core and she went to 215-220 a couple times when I had to run errands around town during 90+ degree weather. Started blowing steam pretty fierce and used up almost all of the reserve tank. Other than that, never above the 210 mark.
Senior Member
Joined: Dec 2010
Posts: 726
Likes: 0
From: Leadville Co
Year: 2000
Model: Grand Cherokee
Engine: 4.7
Originally Posted by bigvig
Mine NEVER goes above 210. EVER! The boiling point of water is 212, so I think anything over 210 is too hot. Try changing out your coolant and put some nice, new, clean stuff in her.
Sent from my Garminfone while fighting off ninjas
Junior Member
Joined: Nov 2010
Posts: 45
Likes: 0
From: Tampa, FL.
Year: 2004 4WD
Model: Grand Cherokee (WJ)
Engine: 4.0 All Factory
Last edited by Roadmister; Jul 14, 2011 at 09:14 PM.
CF Veteran
Joined: Nov 2009
Posts: 8,172
Likes: 17
From: The Republic of TEXAS
Year: 1998
Model: Cherokee
Engine: 4.0L HO
Blew the heater core, steam pretty fierce, in 90 degree weather, used all the bottle and only hit 215-220.....I still think your gauge is wacked.
CF Veteran
Joined: May 2011
Posts: 1,381
Likes: 0
From: EAFB, SD
Year: 1994
Model: Cherokee
Engine: 4.0 HO
How hot is too hot?..........ECU turns efan on at 218F so my guess is that's where the engineers wanted things to start cooling down. If coolant temps are actually north of 222.5, a 180 t-stat would have no advantage over a 195 t-stat.....they're both wide open at 220+ and a properly functioning t-stat only controls MINIMUM coolant temp.
How old are cooling system components? The XJ rad is really dinky, everything must be in top notch condition.
How old are cooling system components? The XJ rad is really dinky, everything must be in top notch condition.
how hot is too hot though? my old one with a split plastic tank didn't go over 230ish according to the gauge.