Sport 2006 RRS running cool on idle

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SeanBeey

Member
Posts
17
Location
Norfolk
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 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
Contents Page Page 14 of 14
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.
 
Sensor details for u

Also enclosed a chart of what the coolest temp sensor should read

So indeed u can see I’m afraid it’s not a simple system and need the live data for the sensors to ensure their in range and see if there’s any fault codes

The engine coolant temperature sensor is located in the top hose at the coolant manifold junction. The ECT sensor provides the ECM and the instrument cluster with engine coolant temperature status.
The ECM uses the temperature information for the following functions:

Fuelling calculations
Limit engine operation if engine coolant temperature becomes too high
Cooling fan operation
Glow plug activation time.
The instrument cluster uses the temperature information for temperature gauge operation. The engine coolant temperature signal is also transmitted on the CAN bus by the instrument cluster for use by other systems.
The ECM ECT sensor circuit consists of an internal voltage divider circuit which incorporates an NTC thermistor. As the coolant temperature rises the resistance through the sensor decreases and vice versa. The output from the sensor is the change in voltage as the thermistor allows more current to pass to earth relative to the temperature of the coolant.
The ECM compares the signal voltage to stored values and adjusts fuel delivery to ensure optimum driveability at all times. The engine will require more fuel when it is cold to overcome fuel condensing on the cold metal surfaces inside the combustion chamber. To achieve a richer air/fuel ratio, the ECM extends the injector opening time. As the engine warms up the air/fuel ratio is leaned off.
The input to the sensor is a 5V reference voltage supplied from the voltage divider circuit within the ECM. The ground from the sensor is also connected to the ECM which measures the returned current and calculates a resistance figure for the sensor which relates to the coolant temperature.
The following table shows engine coolant temperature values and the corresponding sensor resistance and voltage values.


B5DB0C34-D093-42A9-B2BD-7249E100AF82.png



the ECT sensor fails, the following symptoms may be observed:
Difficult cold start.
Difficult hot start.
Engine performance compromised.
Temperature gauge inoperative or inaccurate reading.
In the event of ECT sensor signal failure, the ECM applies a default value of 80°Celsius (176°F) coolant temperature for fuelling purposes. The ECM will also permanently operate the cooling fan at all times when the ignition is switched on, to protect the engine from overheating.
 
Last one, lol

Here’s the engine coolant sensor , it’s as u look at it on the right hand side of the engine by the fan , this is from my D3 which I assume will be in the same place seeing it’s the same engine as ur RRS

B1D1BF15-0FCB-41B8-BF78-5994B438902A.jpeg
 
Link ref the thermostat , posted it here if u needed it

If it is found to be faulty make sure u check ur vin number as they changed late 2006/7

https://www.disco3.co.uk/forum/is-tdv6-running-temperature-128962.html?highlight=Engine+cool

Plse let us know how things go and if u need any more info

How to replace thermostat, press download after you’ve pressed the link

https://onedrive.live.com/?authkey=!AODfHJCOLGxxyy0&cid=4BC2D89C85C7C171&id=4BC2D89C85C7C171!2823&parId=4BC2D89C85C7C171!1457&o=OneUp
 
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I bet the cooling system for a nuclear powered submarine has got nothing on an L322 range rover..... talk about stuff that could go wrong under the bonnet:eek:

Remind me not to go near a L322 then as I thought my D3 with the above info was bad enough :)
 
WOW! Very useful information, the car is booked in for a a gearbox service this Friday so I will ask them to check the ecm readings and I will pass this information onto them to fault find, Thank you so much !
 
WOW! Very useful information, the car is booked in for a a gearbox service this Friday so I will ask them to check the ecm readings and I will pass this information onto them to fault find, Thank you so much !

Ur very welcome , hope there’s enough info for u, just know what it’s like trying to find out faults

Plse let us know how things go
 
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