How hot is too hot?
 

I keep a close eye on the ultra gauge and today it got up to 224 deg while sitting at the drive thru with outside temps at 80deg. To me that seems way too hot even though the factory temp gauge never moved from the middle position. In rural road driving my temps range from 186-194 with a/c on and outside temps in the 90s, stop and go driving around town usualy goes in the 194-204 range but, as soon as im just sitting still the temps began to climb and this 224deg tonight is the highest i have seen. So far I have replaced thermostat with a gray light spring unit, new land rover brand fan/clutch, new water pump and new electric fan with a generic advanced auto unit and I cleaned radiator fins of derbis. I dont know what else to do other then throw a new radiator on it unless, this generic electric fan doesnt move as much air as the factory unit. And I have verified the fan clutch works and the electric fan is coming on. Anyone know what the cfm of the factory electric fan is? Any suggestions or is this temp normal since land rover doesnt feel its hot enough to make the temp gauge move.
thanks

When I replace my radiator, I cut it open. Half way down the tubes were getting plugged. My soft spring thermostat was the key to lower temps.

Did you change the thermostat and radiator at same time?

Replace radiator, water pump, all front hoses and stock thermostat at first. The only way I got my temps down was with grey 82 cell soft spring thermostat. Temps now 187f -194f with outside temps 82f-92f

Replace your thermostat with Soft Sping thermostat PEL500110 you just aren't getting flow through your radiator at idle, which is normal based on the oem design.

I had similar symptoms I would get up to about 215 in drivethrus and traffic if sitting. I have not seen over 195 since I changed the thermostat, best money I ever spent.

Oh and to answer your original question, 225 is WAY TOO HOT! You should really stop sitting in drive-thrus until you change the thermostat. If you must or if caught in traffic you can also try putting your truck in neutral/park and bringing up your rpms while in the drive-thru/traffic, this will increase the water pressure and thus increase water flow through the radiator, your temps should come down.

Whatever you do, do not turn off the truck at that temperature as it will continue to rise with the engine off and you may do damage. Just bring up the rpms and watch it drop.

224 might just be normal at long idle, I got the same number setting in the car with AC on, but otherwise my temps are about the same now as they have been in the past. I guess i never let it idle previously for too long. The reason I am saying that this might be normal is that I just purchased a chrysler town and country, which goes to 230 idle and than the fan kicks in and bring the temp down. The Van has only 33k miles on it so, I doubt that it has problem with over heating. The 3.8l chrysler engine is also push rod aluminum block.

224 is by no means normal at any length of idling. 224 is too hot no matter what the situation is and nowhere close to acceptable. Mine doesn't top 210 under a heavy load at low speeds in 110+ Texas heat.

You may want to evaluate the radiator with an IR thermometer. If clogged, the lower rows are going to be cooler than top rows, by well over 10 degrees. Water just can't move as fast thru sludge or calcium, if at all. So reduced size radiator still works at freeway speed, but not in low speed condition. Made all the difference having my D1 radiator flushed and rodded out, but that is an all metal $600 rad, you can't do that with the thinner aluminum and plastic tank models. About $208 from some of the suppliers on line.

Don't know the exact fan spec, but measurements with an air flow meter on my D1 showed about 30% increase in air flow at idle when fans (2 on a D1) are on.

With all the work done you'll want to be sure that belt route is correct, and that when electric fan is running air is being sucked thru grille and blown at engine, not the other way (my PO did that and "subtracted" air flow).

Heat gauge does not move because that is how it is designed, the ECU sends a pulse width modulated signal (PWM) to keep the gauge at midpoint under a wide variety of conditions. On a D! similar, but by different methodology. Once the engine has warmed, the gauge will stay pointed at spot "X". From the RAVE owner's manual:

Thanks for all the replys, I will check the radiator with a infrared thermostat and see if there is any temp difference between top and bottom. When I changed to the gray thermostat it dropped temps alot, but it made no difference at the long idles with a/c on.

You have probably put your finger on it, if rad is less than 100%, it can't keep up with heat transfer with low air flow. If all you did was drive 30 miles to work on deserted highway, and never idled long, might not notice it until much more build up later.