JK overheating

jorgelrod

Hooked
Throwing this out there to you guys to see if you can shed light on this. I know I play in the mud and I made sure to wash the radiator properly and inspect it. Nonetheless, ever since I switched to the 33" tires with my 3.73 it's been running hotter with 226-228 with the occasional 230-235 but yesterday as I headed to the souther side of the island I was climbing thru the mountains doing 55mph and and 3000rpms and saw the needle go all the way up to 255F with The overheat light going off.
Most of the rest of the trip, 60 miles or so at 65 and 2K RPM it ran at 230,

Any pointers guys? I've thought of flushing and have it removed and washed properly but I am grasping here.
Any ideas??
 

wayoflife

Administrator
Staff member
When you installed your new tires, did you make sure to properly calibrate your speedometer? If not, your shift points might be off enough to cause your transmission to hunt for gears. This can also cause things to heat up on a motor/transmission that likes to run hot. Another thing is to check and see if your fan is in fact kicking into the higher speed. If it not, that won't help any either.
 

IBeHeWhoIsJoshua

New member
Something isn't right here...I would really make sure the radiator isn't caked with mud and surrounding areas. With 3.21 gears and 35's my rig is quite capable of keeping its cool. I do drive it like a manual 75+% of the time though. She hunts for gears like crazy if I don't. Maybe, as Eddie stated, you need to recalibrate for the tires. Just seems to me that's not enough of a tire change size with your better gearing then I have. I would try driving it like a manual and see if that keeps your temperature down. If it does, you've got your answer.
 

wayoflife

Administrator
Staff member
Something isn't right here...I would really make sure the radiator isn't caked with mud and surrounding areas. With 3.21 gears and 35's my rig is quite capable of keeping its cool. I do drive it like a manual 75+% of the time though. She hunts for gears like crazy if I don't. Maybe, as Eddie stated, you need to recalibrate for the tires. Just seems to me that's not enough of a tire change size with your better gearing then I have. I would try driving it like a manual and see if that keeps your temperature down. If it does, you've got your answer.

Agreed, something doesn't sound right. I might even go so far as to pull apart the tranny cooler and condenser and make sure there's nothing trapped between them. Without pulling them apart, it's hard to know for sure if there's gunk still trapped between them.
 

jorgelrod

Hooked
I do have the procal and I did measure the tire from the floor to the top which have me 32" inches and that is what I entered on the unit and flashed it, I'm really grasping, could it be the coolant mix is more water than coolant, I had to put some water on it a while back...
 

wayoflife

Administrator
Staff member
I do have the procal and I did measure the tire from the floor to the top which have me 32" inches and that is what I entered on the unit and flashed it, I'm really grasping, could it be the coolant mix is more water than coolant, I had to put some water on it a while back...

More water would do a BETTER job of keeping your engine cool.

When you say that you measured to the top of your tire, was that to the corner where your sidewall becomes the tread or, was that to the top of the highest point of center of the tread? If the latter, you did this wrong.
 

jorgelrod

Hooked
To the top of the thread, we're was I supposed to measure at, btw, Eddie, yes you can hear the fan going full steam
 

wayoflife

Administrator
Staff member
To the top of the thread, we're was I supposed to measure at, btw, Eddie, yes you can hear the fan going full steam

To the corner where there sidewall makes a 90° turn to become the tread. OR, you could measure from the center of the wheel to the ground and x2. Still, it may not be enough of a difference to change much. Did you take apart your tranny cooler and condenser to make sure it's clean in between them?
 

Nhfd01

New member
You measure from the floor to the top of the tire. Place a level across the top of the tire and measure.
 

jmatta33

New member
You measure from the floor to the top of the tire. Place a level across the top of the tire and measure.

as Eddie already stated this is not correct. with the weight of the vehicle on the tires the air gets pushed to the top of the tire as the bottom is flattened out on the ground slightly distorting the top of tire. so the actual diameter would be easiest measured from center of the wheel to the ground and multiplying by 2.
 

jorgelrod

Hooked
I drove it today, but it's raining like crazy so I haven't been able to run at good highway speeds, but will let you know how it fares as soon as I can test it...
 

wayoflife

Administrator
Staff member
Hate when Superchips is wrong
View attachment 115176

Me too especially being they are a paying supporter of ours and people I work with directly. Fact of the matter is, THEIR INSTRUCTIONS ARE WRONG. The distance from the center of your wheel to the ground is the radius you need to be focusing on. Unfortunately, programmers want to know what "diameter" your tire is and that's why you multiply by that radius by 2. But of course, you don't have to take my word for it. Use a GPS, a friend with a stock JK and an accurate speedo or even a speed trap with a radar and you will know that following Superchips instructions will leave you with a speedometer that is OFF.

BTW, I just sent a message to them to let them know their instructions are wrong.
 
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