Still gettin' hot!
#1
Junior Member
Thread Starter
Join Date: Oct 2012
Posts: 44
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
Still gettin' hot!
ok, rebuilt my 99 4.0 in January, PO kept driving after blowing the lower rad hose and toasted #1  pistons. replaced all hoses, water pump and thermostat at that time. moved to SoCal, overheated while sitting at Border Checkpoint a few weeks ago. replaced rad with a new 2row aluminum one, and a new fan clutch for good measure. it runs around 195 locally, but still overheated last Friday on the I-10 in AZ running the a/c at about 80mph in maybe 97 degree weather. electric fan comes on as it should. due to the utter lack of quality of the Chinese made CHAMPION RADIATOR with it's incorrectly machined unsealable flare fittings and useless oversized quick disconnect fittings, I added a Hayden (made in USA) tranny cooler in front. what's left??? new coolant at rebuild and again this week, might be around 70% glycol by now. I did not replace coolant temp sensor, but it seems to be ok. Help!?!
#3
Junior Member
Thread Starter
Join Date: Oct 2012
Posts: 44
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
that might be an ok idea for the summer, but I kinda want to find the real problem. these things didn't overheat when they were new, so there's gotta be something gone wrong...
#4
CF Veteran
Join Date: Feb 2009
Location: Houston Tx.
Posts: 2,203
Likes: 0
Received 3 Likes
on
3 Posts
Year: 1995
Model: Cherokee
Engine: 4.0
I would over heat all the time in traffic, then I got a new aluminum rad, fan clutch, water pump, 180 degree thermostat, and rad cap, runs at about 182 now, I can sit in traffic and it will reach 200 max.
People will say you need a 195 thermo because that's what the computer is set for to achieve optimum fuel mileage, to those people I say I'd rather spend a little more at the pump than have my engine overheat.
People will say you need a 195 thermo because that's what the computer is set for to achieve optimum fuel mileage, to those people I say I'd rather spend a little more at the pump than have my engine overheat.
#5
Junior Member
Thread Starter
Join Date: Oct 2012
Posts: 44
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
I think I'll get a 180 or 185 degree stat. I heard Stant has a line that're guaranteed plus or minus 3 degrees. maybe throw a sender at it @ the same time. it ate the water pump bearings and the TPS when it blew up for the PO.
#6
Newbie
Join Date: Apr 2013
Location: Southern Utah
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1991
Model: Cherokee
Engine: 4.0
If like to hear how that goes. All my cooling system has been replaced and its not uncommon or my 91 xj to hit 220 when in the city or off road. I read a lot about how people strongly suggest staying with 195 t-stat but I'm ready to give a 180 a try
#7
CF Veteran
Join Date: Nov 2009
Location: The Republic of TEXAS
Posts: 8,172
Likes: 0
Received 14 Likes
on
14 Posts
Year: 1998
Model: Cherokee
Engine: 4.0L HO
........replaced all hoses, water pump and thermostat.......replaced rad with a new 2row aluminum one, and a new fan clutch......it runs around 195 locally, but still overheated last Friday on the I-10 in AZ running the a/c at about 80mph in maybe 97 degree weather......
I know nothing about the radiator u installed but it could be smaller (thinner core), have less fins/", less heat rejection capability than the OE factory rad. Just because it has 2 rows doesn't mean the core is twice as thick. The OE factory rad is really dinky so going with something different than a OE 1 (very wide) row stock style rad could be an issue.
Is the rad fan shroud intact/in place? Big tires? Anything blocking airflow to the grille? So many questions.
......and for what it's worth, a 180 stat will allow it to run a little cooler MOST of the time.....but not when driving 80, in 97 ambient, running a/c. We run a 180 stat and like I said, we've momentarily seen 230, 3 digit ambient, stopped on black asphalt, running a/c. Factory idiot light never flickers so momentarily hitting 230 is not overheating.
Last edited by djb383; 05-05-2013 at 04:30 PM.
Trending Topics
#8
Junior Member
Thread Starter
Join Date: Oct 2012
Posts: 44
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
fan shroud is intact and in place, electric fan in place and operating. new 195deg thermostat was installed in January when it got it's new pistons (and about $750 worth of other stuff) is it possible the thermostat isn't opening all the way? I might also hang a good aftermarket gauge on, or invest in a scan gauge to leave connected so I can keep an eye on other stuff as well...
#9
Junior Member
Thread Starter
Join Date: Oct 2012
Posts: 44
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
fan shroud is intact and in place, electric fan in place and operating. new 195deg thermostat was installed in January when it got it's new pistons (and about $750 worth of other stuff) is it possible the thermostat isn't opening all the way? I might also hang a good aftermarket gauge on, or invest in a scan gauge to leave connected so I can keep an eye on other stuff as well... oh, and the radiator is designed to replace the original, and has 2 columns of flat tubes running crosswise between what looks just like the fins on the original. the vendor claims it's good for 400hp.
#10
CF Veteran
Join Date: Nov 2009
Location: The Republic of TEXAS
Posts: 8,172
Likes: 0
Received 14 Likes
on
14 Posts
Year: 1998
Model: Cherokee
Engine: 4.0L HO
fan shroud is intact and in place, electric fan in place and operating. new 195deg thermostat was installed in January when it got it's new pistons (and about $750 worth of other stuff) is it possible the thermostat isn't opening all the way? I might also hang a good aftermarket gauge on, or invest in a scan gauge to leave connected so I can keep an eye on other stuff as well... oh, and the radiator is designed to replace the original, and has 2 columns of flat tubes running crosswise between what looks just like the fins on the original. the vendor claims it's good for 400hp.
Overheating when everything in the cooling system is new is a stumper. I'm just leary of some aftermarket stuff and I'm not knocking the new rad but basically it's the only thing different. If the core is the same thickness as OE stock (1.25" wide/thick 1 row), then the 2 rows added together are less than OE stock due to the space between the 2 rows. The space between the 2 rows does nothing. Again, overheating with a new motor and new cooling system is a stumper. Go back and review to see if anything else changed from before to after.
#11
Senior Member
Join Date: Dec 2011
Location: Centralia, Wa
Posts: 922
Likes: 0
Received 1 Like
on
1 Post
Year: 1997
Model: Cherokee
Engine: 4.0
As the other guys are saying we need a little more information of the vehicle in question. Big tires? Stock Gears? Obviously its a Automatic as you said you installed another Aux Cooler. Because of the area you live in I'd look at bypassing radiator as your trans cooler. If your cruising down the highway at 80mph with big tires there's a chance you're heating up the cooling system from the hot tranny fluid.
#12
Junior Member
Thread Starter
Join Date: Oct 2012
Posts: 44
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
All stock, no lift (minor butt sag from tired springs), fresh 235/75 15's, not 30-something's. I used to rent these when they were new and don't recall making any hot, though I never set out across the Sonoran desert doing 80 in 100 degree heat, either. I'm either going to try a new sender or buy a ScanGauge. I define "overheat" as the check gauges light and buzzer, with the temp gauge pretty well out of places to go...
#13
CF Veteran
Join Date: Apr 2009
Posts: 4,734
Likes: 0
Received 9 Likes
on
9 Posts
Year: 2015, 2012
Model: Grand Cherokee (WK2)
Engine: 3.6L
The head might have cracked internally when it overheated.
You would likely not see it off the vehicle (the crack) as the head is cold. Magnafluxing the head probably would not show the crack.
Stay with the 195* thermostat. OEM MOPAR is the best if you can find it.
Use 50/50 coolant mix. 70% cuts down on the heat transfer.
You would likely not see it off the vehicle (the crack) as the head is cold. Magnafluxing the head probably would not show the crack.
Stay with the 195* thermostat. OEM MOPAR is the best if you can find it.
Use 50/50 coolant mix. 70% cuts down on the heat transfer.
Last edited by Firestorm500; 05-21-2013 at 01:04 PM.