My 4.0 auto 98 wrangler runs at the desired 210° most of the year, but when the outdoor temperature approaches 100° it bumps up to 213°. The radiator was flushed about 2 years ago. Please advise. Thanks.
My TJ runs over 210 on hot days. Is it time for a new radiator?
- Thread starter MikeO
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OP
IF you flushed your radiator two years ago... it may be time to have it chemically cleaned/flushed and look at replacing the thermostat.
Verify the radiator fins are not partially plugged.
Verify the radiator fins are not partially plugged.
That's what I did and went from an OH condition sitting in a parking lot (@102 OAT) to solid 210 on the gage. Since the radiator was out, I did replace the pump and all hoses as well.
It may show 3 degrees different but the gauge could be reading 3 or so degrees higher or lower than reality to begin with and that's probably within the margin of error. I'm sure it gets hot in NV but I'd be more worried about rattlesnakes until the needle got past the whole number
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It’s not un-common for me to see slightly over 210 at idle, sometimes I’ll turn the a/c off to keep it down.
My cooling system was completely replaced 2 years ago.
My cooling system was completely replaced 2 years ago.
T A
TJ Enthusiast
I'm interested in this. My 97 Sahara automatic runs at 210 but goes higher on a hot day when idling in traffic. Will overheat & check gauges light comes on if I run the AC while idling as well.
That little amount over 210, estimating 213, in hot conditions should be considered normal. I wouldn't worry about it. Make sure though that your fan clutch is operating, that's what turns the fan on when the engine is hot. With the engine hot, check that the fan is very stiff and difficult to rotate by hand. If the fan spins freely when the engine is hot that means the engine can't spin it fast enough which can cause the engine to run warmer. If the fan spins freely when the engine's hot, replace the fan clutch.
T A
TJ Enthusiast
Are there separate sensors for the gauge and ECU? I've seen documentation showing one in the side of the block and it also appears that there is one near the thermostat.
The temperature gauge uses the coolant temperature sensor mounted next to the radiator hose connected to the engine head at the front of the engine.
Kenneth G Zinis
TJ Enthusiast
Mine runs very close to 210, per gauge, regardless of ambient temp or driving conditions, a little less in cool/winter (PA). I checked goose neck temp, at sensor, with IR thermometer and dash gauge is spot on.
Joseph
TJ Enthusiast
I get somewhat of the same issue. I checked today after it ran for a solid 30 minutes. I was able to spin it pretty freely, not a whole ton of resistance. But if I gave it a push to spin on its own, it’d only make about anywhere between an 1/8 - 1/4 of a full turn. It’s never been replaced as far as I could tell, or my water pump. Mopar radiator last summer, head gasket this past winter.
Not to thread jack, but could my fan clutch be an issue?
Time to replace, it shouldn't free-wheel that much when it's hot.
Joseph
TJ Enthusiast
Mobusaki
TJ Enthusiast
Mine used to run a little below 210. Recently it had been running a little above 210, no matter the weather. I replaced the radiator as preventative maintenance (simply because it was 17 years old) and now my temps are back below 210. The old radiator fins were not terribly clean - there was a thin layer of mud I never could seem to get off so I attribute the difference to that.