engine runs too cool-expert advice needed
CF Veteran
Joined: Mar 2011
Posts: 2,570
Likes: 4
From: California
Year: 1992
Model: Cherokee
Engine: 4.0 HO
CF Veteran
Joined: Nov 2009
Posts: 8,172
Likes: 17
From: The Republic of TEXAS
Year: 1998
Model: Cherokee
Engine: 4.0L HO
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
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
Looks like all is with-in spec to me.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
I just wish the heater was warmer. I can't help but wonder if the heater hoses at the core should be warmer than 176*. Like the flow is somewhat restricted in the core.
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
You make me want to custom port my t-stat housing! talking like that. More water where? OK, crummy photo. There are awkward edges and protections causing restriction. The idea is that it's that's far from "ported". I doubt it's designed for crappy machining. My heater core is over 20, couple rounds of Aluma-seal, (to stop fogging).......Anyway, I wonder if there could be a restriction in some t-stat housings?
Last edited by DFlintstone; Oct 30, 2012 at 02:53 AM.
Herp Derp Jerp
Joined: Nov 2011
Posts: 18,251
Likes: 17
From: Parham, ON
Year: 1999
Model: Cherokee
Engine: 4.0L OBD-II
Originally Posted by DFlintstone
OK, crummy photo.
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
I actually keep it front and center on my deck as a "decoration" 
(it's fine. I just have it "on deck"
)
(it's fine. I just have it "on deck"
)
Last edited by DFlintstone; Oct 30, 2012 at 08:10 PM.
Senior Member
Joined: Aug 2010
Posts: 893
Likes: 0
Model: Cherokee
On my '93 YJ I got 13.5mpg (4:10 on 33"). On my '97 XJ I get 13mpg (3:55 on 32")
Have you reset your guages? Turn off the car, off and on with key while pressing the trip button? This resets it, and makes sure everything is working.
Your sensor might be bad. What PSI does it show? Have you put a digital guage (meat therm) in the coolant (radiator cap) and compared?
Have you reset your guages? Turn off the car, off and on with key while pressing the trip button? This resets it, and makes sure everything is working.
Your sensor might be bad. What PSI does it show? Have you put a digital guage (meat therm) in the coolant (radiator cap) and compared?
Senior Member
Joined: Aug 2010
Posts: 893
Likes: 0
Model: Cherokee
Herp Derp Jerp
Joined: Nov 2011
Posts: 18,251
Likes: 17
From: Parham, ON
Year: 1999
Model: Cherokee
Engine: 4.0L OBD-II
On my '93 YJ I got 13.5mpg (4:10 on 33"). On my '97 XJ I get 13mpg (3:55 on 32")
Have you reset your guages? Turn off the car, off and on with key while pressing the trip button? This resets it, and makes sure everything is working.
Your sensor might be bad. What PSI does it show? Have you put a digital guage (meat therm) in the coolant (radiator cap) and compared?
Have you reset your guages? Turn off the car, off and on with key while pressing the trip button? This resets it, and makes sure everything is working.
Your sensor might be bad. What PSI does it show? Have you put a digital guage (meat therm) in the coolant (radiator cap) and compared?
The process you describe doesn't reset anything. On digital instrument clusters that forces it into test mode where it cycles all gauges and lights to show that the stepper motors and light bulbs still work.
And um are you suggesting he open the rad cap with the engine at operating temp? After he fixed it with an OEM tstat?