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Radiator Fan

6K views 5 replies 4 participants last post by  HammFist 
#1 ·
I've noticed that the fan in my 5.7 Hemi does not come on until around 220 degrees and have seen the engine temp on the EVIC go as high 225.
While cruising around town the temp will settle between 200 and 210. Does this sound normal and are you guys getting the same results. My previous two cars (Tundra and 4Runner) would warm up to temp and stay absolutley locked there even going through the desert at 115 with AC blowing. Is there a way to lower the temp setting on the fan?
 
#2 ·
On you're previous vehicles did they have normal guage or a digital readout like the GC? Most companies dumb down their gauges where they hover right in the middle over a wide range of temperatures or otherwise they get complaints that their vehicles are overheating. Its gotten the same with most oil pressure guages. Modern vehicles have very reliable cooling systems and overheating is a very rare thing these days. If it's actually overheating it'd be going quite a bit over 225.
 
#4 ·
It seems that 220 to 230 is quite hot. Especially if I were going to tow.
I believe that the thermostat is 190 or maybe it's 200 in the Hemi. Either way It doesn't make sense that the rest of the cooling system and electric fan in particular would allow the engine to heat up 30 to 40 degrees above the thermostat. I wish there was a way to lower the fan threshold setting.

I liked the fact that my former Toyotas wouldn't budge on temperature even when towing across the desert in the middle of Summer. It doesn't instill confidince that the Jeep temp wanders all over the place when just crusing around town.
 
#5 ·
On the jeep you are able to look at the real temperature. Most temperature gauges on cars and trucks now don't give you a real reading. They are designed to just move to certain points and stay there. So the engine may have to move more than 30 degrees to move that gauge. I wouldn't worry about towing. When that temp gets near 230 the fan kicks into high speed and brings it right down.
 
#6 · (Edited)
What jp467 and mr bots said. All modern vehicles have all sorts of performance information available in the ECU, but they don't usually make it available to the driver. It seems they don't want to spook folks with too much information.

One of my other cars has a fake oil pressure gauge. The oil pressure sensor is actually just a pressure switch, and if the ECU senses adequate pressure, it makes the oil pressure sensor go through a fake dance like it is really reading the pressure. Less than totally worthless, especially since the car won't tell you it has zero oil pressure except by moving the oil pressure needle to zero. No idiot lights, no alarm, just the fake gauge at zero until the loud knocking starts.

Kudos to Jeep for providing this info, as it can be very useful when trouble shooting problems as these trucks age.
 
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