Coolant Temps - 5.0

[M32H32IS]

2012 LR4 US Spec 5.0

I noticed coolant temps are running 5-10 degrees more than normal if I sit for a couple of minutes in Drive (stoplights) blasting the AC.

Driving temps stay the same.

Temps only rise when stopped and in Drive w AC on. If I put it in park and rev over 1,000 rpm the temps go down.

If I run with the AC off, the temps don’t rise above normal.

 

[Nechaken]

Makes sense, especially in TX -- the 5.0 (and 3.0 for that matter) utilize an egnine-driven viscous fan rather than a separate electric one. If you shift into P or N when its hot you'll see the car up the idle speed to ~1050 or so RPM to speed up the cooling fan. But nothing it can do when you're in D and idling at 650 (or whatever). You'll probably notice the A/C isn't quite as cool when stopped, either.

 

[M32H32IS]

Can confirm that the coolant temp stays 91c and below during my morning commute. Same commute. Same stoplights. I guess it loses some efficiency in the extreme heat.

This morning it’s only 88f and functioning normally with AC on blast.

AC temp is also cooler

 

[Tapps33]

It could also be your viscous fan is getting a little weak. If the fan's viscous clutch is slipping more than it's supposed to, you'll never get the cooling factor for both the engine and the AC. Hence the temps will be a little high at idle, and the AC won't be as cold. Once you start moving and get a little more air and engine rpms, everything's good to go.

That said, I have never tried to see commanded vs actual fan rpms via the Gap tool...but I have to assume it's possible.

 

[djkaosone]

I wouldn't be worried about it. In high temps in Death Valley, CA around +115*F, I typically see coolant temp on my Gap IID Tool around 210-215*F at the engine and 185-200*F before the thermostat while blasting the AC.

 

[powershift]

How hot is too hot, 230F?

 

[f1racer328]

230 is kinda hot on the coolant. That’s about where the car decides to shut off the AC and the gauge cluster coolant indicator will move.

It’s not going to boil at 230 if it’s holding pressure. I forget what PSI our cars run at, I think it’s about 25-30 PSI. So around 280-300 degrees F.

You should be running anywhere from 190 - 210. I run around 200-210 degrees when towing a 4500 lb trailer in 110-115 degree weather. (V8)

 

[ugmw177]

curious as to how you are monitoring actual coolant temp?

 

[f1racer328]

GAP IID tool.

Any OBD reader should be able to get coolant temp off our vehicles.

 

[powershift]

230 is kinda hot on the coolant. That’s about where the car decides to shut off the AC and the gauge cluster coolant indicator will move.

It’s not going to boil at 230 if it’s holding pressure. I forget what PSI our cars run at, I think it’s about 25-30 PSI. So around 280-300 degrees F.

You should be running anywhere from 190 - 210. I run around 200-210 degrees when towing a 4500 lb trailer in 110-115 degree weather. (V8)

That is impressive cooling capacity. I'll be driving around in 120F ambient with just the AC on and overland gear so if I hit 230 then it is time to pull over. My blue 2012 HSE LUX ships Monday. Hopefully on Saturday I can take it out into the desert and climb some mountains. It will be hot asf.