This makes me think about air in the cooling system, though I don’t see how if the mechanic didn’t touch that. I would do a simple check to see if the low temperature on the radiator outlet (ECT2) is real. I would use either an IR thermometer, or maybe just carefully touch that pipe where the temp sensor is, or the sensor itself. I’m going to take a peek under my hood to see if it’s at all accessible…

 

Have you also the V8 or V6 Engine? Your are the best, thank you so much for your unbeliveable support so far... I think the V6 is different in this logic, and the ECT2 is also in a different position...

Thank you

 

Ahh, that’s a good point. Both the Workshop Manual and Repair Manual I have are for the V6. Most stuff is the same, but not all. I have an early AJ133 training doc which doesn’t appear helpful, other than it only mentions the ECT sensor on the heater manifold on the back of the engine and not a 2nd ETC.
https://www.dropbox.com/scl/fi/y28ug...=tse2tu3h&dl=0

Also, while the lack of codes isn’t helpful, it’s also troubleshooting information.

If the fan only goes to high speed after a few minutes, then that means the speed control signal (PWM) works, so I’m doubting JagCode’s suggestion of a pinched harness (though not impossible.) However, I agree with JC that’s it likely that the issue is related to the recent work.

I’m tending to think that the fan is operating as it should, something is making it run hard.

Also, the engine temperature display on the dash is garbage. Like most modern cars, once it reaches operating temperature, the display will stay exactly in the middle as long as the temp is within operating range (heavily damped). I’d suggest using your code reader to look at temperatures as the engine warms up.

I would include transmission temp too. I was looking at the transmission cooler, which uses engine coolant to cool the ATF fluid - and you just changed the ATF fluid. I was hoping to find a connection between the transmission temperature and fan control, but I did not see anything.

I assume/hope that your mechanic used the ZF procedure for changing ATF?
https://www.dropbox.com/scl/fi/cfr7s...=gpqi62cv&dl=0

 

ATF Oel was switched 2 years ago from ZF direkt in Germany, Only rear Diff oel and transfer Diff Öl ist new and it is correct Öl in.

 

Ok, got it. Rear diff and transfer case were the only fluids changed this time.

Does anyone have documentation showing the location of ECT sensor 2? I have trouble believing it would be called an Engine Coolant Temperature (ECT) sensor if it was designed to measure ambient air temperature. (The V6 has 2 ECTs plus an Ambient Air Temperature (AAT) sensor.)

For those following along, my phone translated Andi’s pix…

 

Is this the answer?
The installation location is crucial: whilst the ECT1 sensor (primary sensor) is usually mounted directly on the engine block or cylinder head and measures the temperature directly
at the source, the ECT2 sensor (secondary sensor) is located at the radiator outlet or in the return hose on many modern vehicles.

The closed thermostat: As long as the engine is running warm and the thermostat is still closed, the coolant circulates only in the ‘small circuit’ within the engine.
The radiator remains ‘cold’, and the coolant at the ECT2 sensor moves little or not at all. The sensor therefore often displays only the ambient temperature or only a very slow rise.
The opening of the thermostat: As soon as the thermostat opens, the ‘large circuit’ is activated. Hot water from the engine now flows abruptly into the radiator. It is only at this
moment that the hot coolant reaches the ECT2 sensor, leading to a rapid rise in the measured values.

The ECT2 Sensor is in my view not defect or bad. Perhaps the thermostat or the relais is the problem when the cooling fan goes in a high run after 10 minutes

BR
Andi

 

Thermostat: This component regulates the flow of coolant between the small and large cooling circuits to ensure the engine
operates at its optimum temperature. It is one of the most frequently replaced wear parts in the cooling system.
Relay: The Jaguar F-Type has a special radiator fan relay (often referred to as the radiator fan run-on relay),
which is located in the engine compartment. It controls the activation of the electric fans to prevent overheating.

BR
Andi

 

Yes, that makes perfect sense.