TJ 4.0 running warm at Idle with A/C on
- Thread starter Terra
- Start date
My driving habits typically don't warrant it. I only ever notice it in a long drive-thru line during the summer. Any other situation doesn't reproduce the condition. I'm just OCD about cooling.
FWIW even though my Jeep is 20 years old, I have less than 70k original miles on it.
ChasUGC
TJ Enthusiast
Personally, I would never leave my Jeep running in idle, in extremely high outside temperature, with the Air Conditioner on full. That is a definite way to overheat it, and possibly damage your engine. I have that experience from living in the San Fernando Valley in Northridge where the temperatures reach 115 degrees in the summer. In the desert, I'm sure it can be worse. You definitely want that air passing through your grill. If I am driving, and in a lot of stop and Go traffic, with my AC on full, my temperature gauge definitely goes up a little. When I start moving consistently, it goes down. If I'm in the S.F. Valley, on a very hot day, I would rather sweat than risk ruining my engine with the AC on. You can also back flush your radiator, to get the junk out of your fins. Older vehicles tend to shred iron from the engines and it can plug up your radiator fins. I had that problem with an old restored convertible GTA Mustang of mine. I was losing radiators every six months. I noticed that there seemed to be a lot of iron deposits plugging my top fin, when I examined the blown radiator. The top of my radiators kept blowing out and leaking. I put an inline Gano Coolant Filter in my Mustang, on the top hose, and it filled up with engine deposits in two weeks. It was filled with metal iron desposits from my engine that was plugging my radiator fins. I removed it and cleaned it. The filter is clear so you can see if it is filled with iron deposits. After awhile, I didn't have that problem anymore, and the filter stayed relatively clear of deposits, and I completely stopped losing radiators.
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KennethS
TJ Expert
Sorry for the hijack but that terminology has always bothered me.
Are there aftermarket miles?
If so, and the components are replaced, are they now more desirable than original miles that have more wear on them?
Inquiring minds want to know.
Hah! Fair point. The mileage is unusually low on my '03. I didn't want people thinking I had a rebuilt engine/drivetrain
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ChasUGC
TJ Enthusiast
Correct me if I'm wrong, but I believe original miles are on the original engine. I have 215,000 original miles on my TJ, and I'm the original owner. *crosses fingers* to get to 300,000.
KennethS
TJ Expert
So aren't those just miles?
Would you go on a date with someone who claimed to have 35 original years?
ChasUGC
TJ Enthusiast
annihil8ted
TJ Enthusiast
That gauge from the first picture is pretty neat! Is that a custom solution?
I also feel if the ambient temperature is about 115+ plus dry heat (not as good as a humid thermal conductivity), there's a good chance that heat isn't properly being dissipated at idle, especially with the AC on and taxing the engine
No, it is from amazon. 32 bucks, connects to OBD.
https://www.amazon.com/dp/B0957V8VMC/?tag=wranglerorg-20
It can show bunch of stuff, like voltage, throttle, air fuel ratio, whatever is in OBD.
I am monitoring IAT (intake air temperature), but in 2004 this sensor in the manifold, so pretty much shows the manifold temperature.
I think that having something like is a must for anybody trying to understand how the temperature works in his rig.
annihil8ted
TJ Enthusiast
Sounds like a good piece of gear/upgrade to have
We're in a similar climate to OP and while I haven't seen the gauge go past 210, I'm dubious of the accuracy of the dash/gauge so hopefully OBD will be able to give a better (digital) reading. I too run almost full AC but haven't seen it climb higher than 210 in idle although I'm only in idle for as long as a light turns green
We're in a similar climate to OP and while I haven't seen the gauge go past 210, I'm dubious of the accuracy of the dash/gauge so hopefully OBD will be able to give a better (digital) reading. I too run almost full AC but haven't seen it climb higher than 210 in idle although I'm only in idle for as long as a light turns green
annihil8ted
TJ Enthusiast
Oh another thing crossed my mind. What's your mixture of coolant to water? Given that it's summer and I'm planning a flush later down the line, I'm running almost mostly water, possibly 80-20? Essentially the last few times I've topped off, I've filled with DI water only and no coolant. I do know that coolant can raise temps marginally when compared to DI water
I mentioned I'm running 60/40 water/coolant for that very reason! Your head's in the right place.
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