I think my garage will have to change the coolant temperature sensor, in the housing near the thermostat. My search says I need the "push in" model, not the threaded one. Remove the throttle body and then the sensor housing below it. And then finally, remove the sensor. Is there a good Permatex sealant to use on the older seals, if I can't run down replacement seals? Your opinions are requested. In the time leading up to the garage appointment, I have an OBD2 gauge showing me the coolant temperature. ( I wonder how?) Outside today, the weather is at 0 degrees C or 32F.

 

What stimulus is leading you to replace the sensor? A particular code?

 

Hi. I have on the dash, where the clock usually is, a yellow triangle and "Engine Temperature Indication Fault".

 

Would be useful to pull the code to see specifically what the fault is.
On a 2007, it could be the thermostat.

 

I will go for codes tomorrow. My digital aftermarket gauge is showing a low outside temp upon the start up and a gradual rise to the thermostat operating temperature!

 

I’m gonna guess you’ll find P012800
(Coolant Temperature Below Thermostat Regulating Temperature)

If so, your thermostat is stuck partially open due to its gasket stretching out of shape and blocking it from closing. The coolant takes too long to reach a particular temperature, and the code is thrown.

 

Upon start up this morning, the warning is gone! I will still look for codes, but I have an alternator to have tested this morning.

 

Glad it has cleared for you.

And please don’t use the term “Permatex” again;-)

Cheers!

 

@sony2000 You should correct your Public Profile - a lot is missing.

 

The stored code is P0116(24) ECT. Last week I had the serpentine belt and alternator replaced. Parts of the throttle body piping was removed to access the top of the serpentine route. The coolant temp. sensor may of had an interruption of current. But fault hasn't returned.

 

Do a hard reset to clear the P0116, see this thread:
P0116 Resolved

 

Yes my search brought up only that thread, when I was in the bar. Its very good to know I can check the ohms from the neighboring wire connector, but I shy away from hard sets. Would only use, as a measure of last resort. Through out all this chaos, I am so thankful of having secondary indications of coolant temperature and charging voltage.

 

What often happens with the AJ133/134 is the gasket surrounding the thermostat perishes no longer sealing coolant in the housing resulting in coolant bypassing the thermostat prior to it reaching the correct operating temperature.

The best solution is to replace the water outlet, which contains the thermostat and coolant temperature sensor. The water outlet assembly carries JLR part number AJ811793.

 

The heater return hoses to the throttle body and EGR valve feed hoses that are under the inlet manifold are also know failure points and should be replaced. The JLR part numbers are AJ811763, AJ811766, and AJ811761.

 

The water outlet assembly can internally break below the thermostat and the piece then travels to just above the coolant pump, partially restricting the flow(this seems to be a age related issue with engine bay thermo plastic becoming brittle) replacing this component which has the thermostat sensor and thermostat itself included as an assembly would be common sense whilst you have it apart.
This happened to me whilst standing in stationary traffic causing the fans to run at full speed and triggering an over heating warning on the gauge cluster.

Paul

 

Yup, and that causes the P0128 code to be thrown.