Hi guys I have a 2006 RRS L320 the car get up to temperature fine whilst driving but as soon as the car is idling again the temp drops to around 50-60 degrees.
I though the usual signs of thermostat was cool when driving and normal temp on idle ?
Hi
As
@Datatek also mentions these are controlled by sensor and ECM
U really need it plugged in to read the live data , also has ur antifreeze been tested / changed
The info below is for a 2.7 TDV6 , don’t know if urs is an auto or not
Hope it helps and will find some more sensor info for u so when u get it plugged in u can see if they match up
Here’s a bit of info for u
When the engine is running the coolant pump is driven by the ancillary drive belt. This forces coolant to circulate around the engine and heater, while the thermostat and bypass valve are shut. As the temperature and pressure increases the bypass valve is forced open allowing coolant to circulate through the bypass valve. When the temperature reaches 82°C (180°F) the main thermostat begins to open, allowing coolant to circulate through the main radiator. As the thermostat progressively opens (fully open at 95°C (203°F)), the bypass valve progressively closes forcing any coolant through the heater or radiator. Once coolant is allowed to circulate through the radiator, the transmission fluid (automatic models only) and fuel coolers begin to receive coolant flow.
The increased coolant volume, created by heat expansion, is directed to the expansion tank through a bleed hose from the top of the radiator. The expansion tank has an outlet hose which is connected into the coolant circuit. This outlet hose returns the coolant to the system when the engine cools.
Coolant flows through the radiator from the top right hand tank to the bottom left hand tank and is cooled by air passing through the matrix. The temperature of the cooling system is monitored by the ECM via the Engine Coolant temperature (ECT) sensor located in the cylinder head. The ECM uses signals from this sensor to control the cooling fan operation and adjust fuelling according to engine temperature. For additional information, refer to Electronic Engine Controls (303-14C Electronic Engine Controls - 2.7L Diesel)
To control the cooling fan, the ECM sends a Pulse Width Modulated (PWM) signal to the cooling fan module (integral to the ECM). The frequency of the PWM signal is used by the cooling fan module to determine the output voltage supplied to the fan motor.
The ECM varies the duty cycle of the PWM signal between 0 and 100% to vary the fan speed. If the PWM signal is outside the 0 to 100% range, the cooling fan module interprets the signal as an open or short circuit and runs the fans at maximum speed to ensure the engine and gearbox do not overheat.
https://myvpn.dealerconnection.com/extdealerlrprod/xml/parsexml.jsp,DanaInfo=gtr.fran... 10/25/2005
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The ECM operates the fan in response to inputs from the ECT sensor, the transmission oil temperature sensor, the charge air temperature sensor, the A/C switch and the A/C pressure sensor. For additional information, refer to Air Conditioning (412-03A Air Conditioning - 4.0L)
The speed of the cooling fan is also influenced by vehicle road speed. The ECM adjusts the speed of the cooling fans, to compensate for the ram effect of vehicle speed, using the Controller Area Network (CAN) road speed signal received from the Anti-lock Braking System (ABS) module.