Overheating after longer drives and highway speed

[jeeptorino68]

So recently swapped my engine due to internal engine noise.
Now i have an overheating issue.
I kept my old engines water pump abd thermostat since they were newer.
I habe good heat and have tried getting the air out several times.

It gets hot (220+ according to my obdii gauge set) after longer highway drives. The dash gauge needle is straight up.
Mechanical abd electrical fans work. Usually dont see temps like that unless running uphill in summer loaded down with gear or towing. Plenty of heat out of the heater. The temps are slow to warm up around town on my normal trip to work (less than 10min)

Filled with 50/50 zerex and water

I think I know what I should replace but wanted to get other ideas.

 

[uss2defiant]

One of the first issues i had to tackle on the jeep was my e-fan.
Although it always worked when i was troubleshooting, it was intermittently working due to a bad connector while driving.

Looks like you have an 02 so you should have the same multispeed version that i have.

Check to see if the e-fan connector is extremely hot and signs of the plastic connector melting around the pin.
I spliced in new line to the harness and a non-mopar water proof connector which 100% solved my problem.

I did also put in a new fan from autozone w/ the lifetime warranty.

 

[LibertyTC]

Are you using a mopar thermostat?
The Electric fans while parked on my jeep kicked on while parked at 219F and turned off at 215.
The fan should come on with any A/C position selected as well.

 

[HoosierJeeper]

220 is pretty normal I think, by straight up do you mean the gauge is in the middle?

 

[tommudd]

THE GAUGES ON THESE ARE BASICALLY IDIOT GAUGES

i run a scan gauge on all 3 of mine , they all run at 197 degrees on the road etc
In town, off road, slowly driving they will get to 218/220, then fans kick on and bring temps back down
Just did a 950 mile road trip, ( in the 03 ) with some long uphill pulls ( Ohio to North Carolina and back ) and never seen above 216 running 80-85 most of the time
So how are you getting the actual temps ?

 

[JeepJeepster]

Ive had an HD clutch on my cooling fan for awhile and while I believe its hurting my mpg, the engine stays right at 204F no matter whats going on. Ive towed so much that it was struggling to maintain 55mph in 90F heat and it was right at 204F. The transmission on the other hand, it was close to 250F....

Is the radiator original?

 

[jeeptorino68]

One of the first issues i had to tackle on the jeep was my e-fan.
Although it always worked when i was troubleshooting, it was intermittently working due to a bad connector while driving.

Looks like you have an 02 so you should have the same multispeed version that i have.

Check to see if the e-fan connector is extremely hot and signs of the plastic connector melting around the pin.
I spliced in new line to the harness and a non-mopar water proof connector which 100% solved my problem.

I did also put in a new fan from autozone w/ the lifetime warranty.

I'll check the connector. You know, I swapoed to the heavy duty relay....but wonder if it has failed. I have the original still i can go back to. Thanks

 

[jeeptorino68]

Are you using a mopar thermostat?
The Electric fans while parked on my jeep kicked on while parked at 219F and turned off at 215.
The fan should come on with any A/C position selected as well.

I cannot recall if I reokaced with mopar or another brand my hunch is bad thermostat. Maybe it got stuck with some debris. Or just when changing the front timing cover over to the new engine it got jostled and failed...?

 

[jeeptorino68]

220 is pretty normal I think, by straight up do you mean the gauge is in the middle?

Yea that is what i mean. I thought that would be 210....

 

[jeeptorino68]

THE GAUGES ON THESE ARE BASICALLY IDIOT GAUGES

i run a scan gauge on all 3 of mine , they all run at 197 degrees on the road etc
In town, off road, slowly driving they will get to 218/220, then fans kick on and bring temps back down
Just did a 950 mile road trip, ( in the 03 ) with some long uphill pulls ( Ohio to North Carolina and back ) and never seen above 216 running 80-85 most of the time
So how are you getting the actual temps ?

I'm checking my temp with an autel maxtrip I think. Its plugged in full time while driving gives temp reading. Yet thw gauge just points straight up...indicating normal...

 

[jeeptorino68]

Ive had an HD clutch on my cooling fan for awhile and while I believe its hurting my mpg, the engine stays right at 204F no matter whats going on. Ive towed so much that it was struggling to maintain 55mph in 90F heat and it was right at 204F. The transmission on the other hand, it was close to 250F....

Is the radiator original?

Same I have the electric and hd fan clutch too. Never had an issue
Not the original radiator. I believe csf was the replacement brand

 

[JeepJeepster]

Before adding my mechanical fan, the engine would always be at 193-195F when moving, no matter the temp. When I would stop it would creep up to 217F then the fan would kick on, I think it would go back down to 198-200F then creep back up. After swapping out the original stat for a new mopar stat it now stays at 204F or so, ~10F higher than the original mopar stat... This was with the A/C off of course.

Maybe that engine had some junk in it that partially clogged the radiator.

 

[uss2defiant]

also do a cooling system pressure test.
I had a hair line crack on my reservoir tank that took some real inspection to find.
Pressure testing didn't reveal it for some reason.

 

[jeeptorino68]

Thermostat was installed backwards! Ug
Put in a motorad ultrastat all is well again aside from some air to work out of the system