So last night I put a new MAP sensor, both upper and lower coolant temp sensors and the fuel pressure regulator. Also a new thermostat. I did all this because I'm moving to Austin on Sunday and I'm driving the truck there.

Before all this was done, the gauge needle was always below the center line. Usually on the "A" of "Normal". After doing all this work, it is much higher. usually between the O and the R, but at lowest its just at or slightly above center. It also warms up super fast, within 3 minutes.

Today, it did something ive never seen before. The outlet hose from the heater core and the upper radiator hose, both of which go to the thermostat housing, were sucked of all air and coolant and looked like you took a straw, plugged one end and then sucked the air out of it. They eventually went back to normal, but everything was still super hot. the radiator, hoses, everything. I put a second new thermostat in just to eliminate a bad thermo. It doesnt seem to be doing it now, but with the temp running as high as it is, i can't help but think its related.

I'm leaving in 36 hours and I desperately need to figure this out before I drive 1200 miles.

i took a photo, but i cant upload it, so hopefully this thing i did below gives and idea.


-------
N
O________________this is where it is now, after the work.
R___
M________________this is where it was before
A
L
---------

 

My ’03 3.0L run mid way on the OEM Idiot Gauges but we know they are reference only.

Radiator… Cap…

I haven’t seen a hose sucked in a long time funny, air locked some how.
Try running with the Radiator Cap loose see what happens.

As far as the temp going up after the work, could be one of the other parts was going bad and the new ones are reading correct.

Did you flush the system and change the coolant when you did the other stuff ?

Has the system over heated and boiled over since the parts replacement ?

What are you using for coolant, just curious.

If problem continues, once the truck is HOT, you might check the temp of the coolant with an thermometer.

Just thinking out loud, luck on the coolant and the trip.

 

radiator is brand new and working well, same with the cap.

I used a Thermal Laser Thermometer and here are the temps

Upper sensor - 126-35
Lower Sensor- 180
Physical Radiator- 1150
Upper Rad hose - 139
lower rad hose-115
water pump - 187
Thermostat housing-210

one side note which I forgot until just now when I crawled under to get the temp, I couldnt get the lower coolant temp sensor screwed in all the way. So about 1/3 of the threads are still outside of the motor.seriously doubt thats going to make any difference, but I didnt want to force it in and rise stripping the threads or cracking the block.

 

To me the radiator seems too hot.
The rest appear normal.
You need the water temp, remove the cap and get a reading, watch the hot coolant.