Cold temperature gauge and fans on!!

M

mikew1978

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2

• May 16, 2011

• #1

Can anyone help?
I have a 2003 LR Freelander 1.8 K-series.
When I turn the engine on and drive the car, the temperature gauge comes up to approx. half way, as per usual. And then for some reason, not necessarily tied to time or speed, the temperature gauge drives to 'cold', but still registers. This in turn makes the radiator fans come on. If i turn the engine off and wait for the fans to go off, i can restart the engine (either immediately or after some time) and the temp gauge comes back up to approx. half way again.
I have replaced the thermostat, and degunked the cooling pipes to check for blockages.
I dont have a clue what is going on here as i would have thought that if the engine was overheating, the temp gauge needle would go to 'hot'. Also, the car uses a little bit of water coolant after a long journey, but nothing sinister.
Any help would be appreciated.
Cheers, Mike​

 

The Mad Hat Man

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• May 16, 2011

• #2

The temp guage goes to cold - which switches the fans on???

 

N

nickcc

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Helston Cornwall

• May 16, 2011

• #3

I had a similar problem with the 1.8 K series engine in the Rover 75 I owned some years ago, it turned out to be a faulty fan sensor which kept the fan running (fitted in the rad on the Rover 75).

 

jamesmartin

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louth lincs

• May 16, 2011

• #4

low reading guage can be lack of coolant air dosent transfer heat to sender like coolant but another clue is cold blowing heater when set for hot for same reason

 

fanatic

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• May 16, 2011

• #5

Combustion gas bubbles can make temperature sender do odd things like fans running unexpectedly/ poor circulation etc-get a sniff test done by garage.

Get them to put gas analyser under bonnet with engine running (background HC) then hold over expansion bottle-if it jumps =HGF

 

Optimus Prime

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Garden of England

• May 16, 2011

• #6

sounds like it could be a faulty sender unit, or connection to it.

if the ecu can't read an engine temperature, it fails safe and turns the fans on just in case, the gauge would then also read cold.

 

Northern Irelander

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N. Ireland

• May 16, 2011

• #7

As above - dodgy temperature sensor,

The ECU reads resistance, less resistance as temperature increases, same effect when you disconnect the wiring to the sensor....fans come on.

You say it registers on the gauge, so wiring is still intact or at least getting some connection.

 

Last edited: May 17, 2011

M

mikew1978

New Member

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2

• May 17, 2011

• #8

Is the sender unit the same device as the thermostat?? I have changed the thermostat without any change to the problem.
BTW- i drove 15miles this morning at 70miles/hour without the temp gauge doing anything untoward. Maybe it has fixed itself !! haha, i wish !

 

N

nickcc

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2,634

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Helston Cornwall

• May 18, 2011

• #9

The fan sensor unit tells the fan when to come on by sensing the water temperature and is not the thermostat. If possible follow the wiring from the electric fan/fans and this should lead you to the sensor. Pretty sure someone with the same FL as you will be able to advise the correct location.