2003 ford ranger xl with 2.3 duratec with 49k on it. After doing a massive amount of work to the truck over the last year. And now being able to drive it more then a couple miles at a time. Here's the problem. At idle the coolant temperature stays around 217 to 220. When I drive it. The temperature goes up to 255 degrees. And When I park the truck . and let it idle. The temperature goes down to 234 degrees. The radiator is new the water pump, thermostat and engine clutch fan is new. As well as the antifreeze. When I drive it again. It goes back up to 255 degrees. And yet the engine feel cool to the touch. Is this high temperature normal? If not? Is there away to bleed the air outta the system? I'm thinking maybe exhaust system. Might be stopped up. The truck was formerly an off road fleet truck. Driven at very low speeds. And was most likely left idling for extended periods of time. Does any one have a solution to this problem ? Before I put hundreds of dollars into a new exhaust system.

 

The temperature reading is wrong if engine feels like "normal temp", where are you getting those numbers?
If it is from an OBD2 reader then what model is it?

OBD2 would get temp reading from ECT(engine coolant temp) sensor.
There is also an ECT SENDER, not a sensor, it is connected only to dash board temp gauge.
Ford temp gauge usually has 210degF as the center line, engine would normally stay below the center line except when hauling a load or climbing a longer grade(hill)

What does heater output feel like, above 240degF would be very very HOT

Normal operating temp would be 190 to 220degF, thermostat should be a 192 or 195degF model


You usually bleed air by loosening and removing a heater hose, then refill system until coolant is coming out that hose and its connection, reseal hose.
Any other air in the system will be purged after engine warms up and thermostat opens, any remaining air will be trapped at top of rad and pushed out when cooling system pressure gets above 14psi(or whatever rad cap rating is), it will bubble up in overflow tank and be gone.
When engine cools down(turned off), coolant will be pulled back in from overflow tank to replace the space the air was taking up.

 

Thanks, I just got the truck Finished up today. Now I am working out all the bugs in it. It's been sitting for years. No body knew why the Orange grove quit using it. Once I found the hole on the front of the intake. It made since why they parked it. Vacuum leak causing the rough idle and misfire on number 1 cylinder. That aside! I use the actron scanner. It was something like. $279.00 about. 3 years ago. its its Not the cheap. $80 dollar one. That only. Gives codes. Anyways, thanks for the info on. Which one it reads off of. The temp gauge is where you said it should be. So the truck is fine on the coolant temperature.

 

I would replace the ECT sensor if gauge reads correct.
Computer uses ECT sensor data for cold starts and air/fuel mix after engine warms up.
I am surprised there is no Check Engine Light(CEL) with those temps.

Computer sends ECT sensor 5volts on 1 wire, then reads voltage on the other wire.
3.5volts is about 50degF
2volts is about 110degF
.5volts is about 200degF
.25 is about 250degF

 

I agree! You would think the an over heat light would come on. Nothing! Will have to replace it. Right now I don't drive it. After checking the radle in the front end. New upper & lower control arm asseblies plus new shocks, sway bar bushings, end links and tie rod ends. Are in the future. Then off to paint. Think I am going to give it to mom and dad as there 50th wedding anniversary present. So no expense is being spared spared on it.

 

[/IMG]