Overheating

[stamp11127]

Doesn't sound like it is running long enough to heat the coolant to the point of opening the t stat. The radiator comes into play once the t stat opens.

 

[Canyon Man]

There still must be air in it somewhere..

 

[Bedrck47]

As far as radiator blockage goes, could I just remove upper and lower hoses, put my garden hose in upper and see how it flows out the lower?

yes that should give you a good idea

 

[Bedrck47]

with the gauge coming on at the half way point I would suspect the sensor. need to get a ohm value of the sensor

 

[Canyon Man]

New code...P1289, I'm researching it now.

 

[Bedrck47]

check this link

Part 1 -Troubleshooting P0117 and P0118 ECT Sensor Tests (4.6L, 5.4L)

 

[Bedrck47]

DTC
P1289 - Cylinder Head Temperature (CHT) Sensor Circuit High Input (PCM STRATEGIES UP TO AND INCLUDING 1998)

Description
Indicates a CHT sensor circuit malfunction (shorted).

Possible Causes
Grounded circuit in CHT harness
Damaged CHT sensor
Improper harness connection
Damaged PCM

Diagnostic Aides
Using signal simulation, disconnect sensor and simulate a voltage on sensor signal circuit. Simulated 1.0V signal and scan PID voltage value should be similar. If voltage is similar check sensor, if voltage is not similar check related circuit and PCM. Note DTC P0117 may also be reported, this will activate the MIL light.

 

[Canyon Man]

dammit...Radiator is fine. As I filled it from the top it flowed now problem through the bottom. Back to the drawing board,,,,Has to be air somewhere..Also checking wiring like you stated Roxy1225

 

[Bedrck47]

Going back to post #11 in this thread you reported temp gauge reading 259 but the hoses were much lower if the sensor is giving a false reading then the temp thru the hoses would seem normal

other than a high gauge reading were you having any other signs of overheating??

the gauge reading half way this morning after sitting for 12 hours makes me think the sensor is bad

 

[Bedrck47]

one way to check this would be to get a new sensor but don't install it just yet
connect it to the connector and see where your gauge reads if the gauge reads where it should be when its a cold engine then that would prove the original sensor is bad.

then with just having the new sensor connected try to put the sensor in some very hot water and see how the gauge reacts if everything then acts normal replace the sensor that's in the engine.

before doing this try to get the ohm reading on the new sensor

 

[Canyon Man]

FIXED......................................Details to follow shortly

 

[Bedrck47]

good to hear

 

[Canyon Man]

False alarm........back to problem

 

[Canyon Man]

So here is what I did..........
1. Removed thermostat
2. Took off upper radiator hose and forced water through the hose back to engine
3. Did this for about 10 min while water ran through upper radiator hose connection
4. Quickly buttoned it up as not to lose to much water.
5. At this point we have 100% water in coolant system
6. Turned key to on position and temp gauge showed needle in middle.
7. Hooked up my computer and erased all engine codes
8. Started up vehicle, a little rough for a few moments then purred like kitten.
9. Ran for 35 min temp needle stayed in middle.
10. temp readings from ir gun. Upper 122 deg, lower 100 deg.
11. After 35 min of running all of a sudden temp gauge started to slooowly peg out.
12. Turned off vehicle and walked away shaking my head
13 At this time, the upper radiator hose reads 126 deg and the lower 102. And the computer says my head temp is 246

Forgot to mention. During this process the cap has been off the hole time

I have yet to put my multimeter on the sensors. And I have no codes anymore but I have been turning off engine before the temp gauge completely pegs out. I am done for the day but tomorrow I will begin checking the temp sensors

 

[Bedrck47]

there is another way to check and that would be to get some resistors from radio shack and put across the connector and see how the gauge reacts

 

[Bedrck47]

I would use a 1, 10 and 25 ohm resistor or if you can get a variable resistor 0-50 ohms

 

[Canyon Man]

I am also a geek as well as gearhead. I have resistors in my basement

 

[Canyon Man]

one way to check this would be to get a new sensor but don't install it just yet
connect it to the connector and see where your gauge reads if the gauge reads where it should be when its a cold engine then that would prove the original sensor is bad.

then with just having the new sensor connected try to put the sensor in some very hot water and see how the gauge reacts if everything then acts normal replace the sensor that's in the engine.

before doing this try to get the ohm reading on the new sensor

I will try this tomorrow. I still have the old motor and can get it off the old one

 

[Canyon Man]

OK, I lied. I had a little energy left in me. I plugged in the sensor from my other motor and the temp gauge went to low where it should be

 

[Bedrck47]

sent you a reply to your PM