So I installed a temp gauge months ago before doing anything. Even on a warm day on the highway it's usually around 190, idles in traffic with AC up to max 210.
I just put in a new radiator, water pump, LR brand thermostat, did a flush, and did an electric fan conversion kit on its own thermostat control.
Now it will idle around 200-215 (fan comes on around 200 as I've set it) but under load on the highway or in town just driving the temp climbs to, and maintains around 220. I never got it that hot before with the 100,000 mile old radiator and water pump. At idle the fan seems to do the job, but why on earth does it run so hot driving down the road and highway?!?!
I get a good steady stream of coolant only without bubbles when bleeding and the heater gets plenty hot. That fan moves tons of air for sure.
What else am I missing here?
It cooled just fine before! I did this work as preventative maintenance and it made it worse!

 

You've got your fan set too high. Set it around 180. Also, did you get the LR 180 thermostat or the factory 190?


lastly, what fan did you use?

 

Yep set the Efan control to 180F. I'll never run a 100% Efan setup myself, but lowering the fan controller to 180F should certainly help.

 

180?! It would literally never turn off. I've never seen my temp get that low with my gauge. I have the temp sender right out of the water pump.

But none of that explains why it's hot at highway speeds when the fan shouldn't be needed.

 

I got the standard thermostat btw. Somehow I'm wondering if my previous one was a 180.

 

note on temperature readings I just thought of; mine is an inline sender just outside the water pump and everyone who uses ultragauge should know that their readings are coming from the bottom of the radiator via the sender to the ecu, which only gets full flow when the thermostat is open, and then will already be at least a little cooler than where mine is placed. I'll hook up my OBD and see how the temps compare tomorrow.

 

You still haven't told us what brand fan you have. If it's that eBay kit, there's your problem. The shroud in the eBay kit kills airflow on the highway. You can ask Charlie_V all about that.


You need to remove the 190 thermostat and either throw in a 180 lr stat or do the inline thermostat conversion (my preferred method, as well as the preferred method of many others).


And yes, you're correct about the fan never turning off. The radiator fan, at least on these trucks, shouldn't. They get too hot too easily. I have an electric fan setup and mine comes on at 180 and I've had absolutely no overheating issues ever (knock on wood). 220 degrees is way too hot. Regularly seeing temps of 203 is about my limit, but I've got mine to where it never goes over the mid 190s. That is with a Ford Taurus/Mustang fan, 180 degree controller, and the inline mod with 180 degree thermostat. Even with the Motorad 180 thermostat (don't buy one of those) I very rarely saw temps over 201.

 

Yea, what brand are you using. Dont say FF dynamics.....

This is your problem right here.
Unless you have a higher quality fan shroud with built in flaps like the one in the picture below

 

Yep the Viscous Fan is never off... You CAN NOT run around with a fan that just comes on/off for a little bit. That thing will overheat n die pretty quickly at that rate.

I am truly a believer in an Viscous Fan/Efan setup. I almost blew up a perfect 5.3L LS3 V8 over a 500.00 Efan kit.

 

Ff dynamics indeed!
Well wtf am I going to do with that information now? Anyone have proof of their bad design so I can work something out with them?