While I have one of WhiteXKR's RealGauge temperature kits it is installed in the web package net in the trunk. I fully intend to get it installed as soon as I get a round2it.

In the meantime I have been playing with the TORQUE Pro Android app.

A month ago I had the lower radiator hose blow off at the thermostat dumping all the coolant. Fortunately, it soaked the top of the engine and instantly shut it down and I don't suspect any heat damage. Twelve year old soft hose on the plastic housing with a single clamp just blew off.

In the repair effort I tested, several times, the thermostat using the boiling-water-on-the kitchen-stove test measuring the opening temp with an IR temp gauge. The thermostat had been changed with a coolant change a couple years ago. It opened reliability at 84* C multiple times so I do not question it nor did I replace it.

Since everything was open and dry I replaced the upper and lower hoses, the plastic thermostat housing and the upper crossover pipe to thermostat tower with a new included temperature sensor .

Now the issue: While the Jaguar temperature idiot gauge is rock stable at mid range the TORQUE Pro app displays 96*C plus or minus 2 degrees. The fans are always on.

I am out of town away from my IR gauge. Is this a faulty new temperature sensor or a problem with the TORQUE Pro app?

 

Test Point, I would be looking for some sort of restriction or maybe the thermostat is not preforming like it should under pressure. The fans would be doing what they should at that reading.


Wayne

 

Don't the fans run when the a/c is on? Turn the a/c off and see what takes place.

 

The fans run continuously with the AC off and outside temps in the 30's which is what has brought the temp sensor into question rather than the TORQUE app. I will be able to determine specifically when I get home with my IR temp gauge.

A concern is that this situation would have never have been observed without seeing the temperature output that the ECM thinks it is seeing . . . or . . . the TORQUE app display is not correct.

 

What's the problem with 96? Sounds about right. Would be for an S-Type with the same engine.

 

I was thinking the same thing. 96c, 204f, sounds about right.

 

It has a 80*C/183*F thermostat installed.

 

Do the fans run continuously even before the car warms up? It sort of sounds like the fan relay might be sticking on.

 

So? The PCM is aiming for about 96 and will just shut off the fans to get there if it has to, I reckon. If you're trying to run cooler than 96 then fit a sensor that lies rather than change the thermostat.

Modern engines normally are designed to run hot to improve mpg and lower emissions.

 

Further tests:

With the engine up to operating temperature, AC off, and the fans turned on by the ECM the IR temp gauge reads 82C/180F on the brass portion of the sensor mounted in the crossover pipe. Sorta matches the expected temp based on the installed thermostat. Best I can tell from reviewing SNG Baratt's excellent parts book that is the only coolant temp sensor reporting to the ECM. The TORQUE Pro software attached to the OBDII data port is reporting through the ECM that the coolant temp is 96C/205F. That appears to be keeping the fans on more than expected especially during the recent cold weather.

The suspect elements are the new temp sensor in the crossover pipe . . . or . . . the software interpretation of the resistance/voltage of the new sensor. Unfortunately, the old cracked crossover pipe was disposed of so I cannot try the old sensor.

Two solutions paths I see: install WhiteXKR's modified temp gauge, which I need to do anyway, for comparison to the OBDII TORQUE reading or asking Coventry West to replace a suspect new sensor. If the temp gauge conversion reports the same temp then the sensor is definitely the problem.

This whole situation could have very easily not been noticed except for observing the fans running in very cold weather coupled with a temp reading that is not normally displayed.

 

Did you do a hard reset after the change?

 

I would expect RealGauge to report the same temperature you are seeing on Torque Pro, since its readings are also based on the coolant temperature sensor (though indirectly as interpreted by the ECU and instrument cluster computer).