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Model specific boards => Golf mk3 => Topic started by: wpisme823 on 10 January 2011, 10:53

Title: Coolent Temp Sensor
Post by: wpisme823 on 10 January 2011, 10:53

Hi,

Just a quick question, my car (golf mk3 1.4 se) is running rich so im about to buy a new coolent temp sensor to see if it cures it.
..
If the temperature gauge on the dashboard is working fine does this mean the temp sensor is ok??

Just want to make sure before i spend 14 quid on it

cheers

will

Title: Re: Coolent Temp Sensor
Post by: Deano2711 on 10 January 2011, 10:56

I may be wrong but I do believe the coolant temp sensor would not have anything to do with your car running rich. Also if the temp guage is working ok the sensor should be fine. 

Title: Re: Coolent Temp Sensor
Post by: wpisme823 on 10 January 2011, 11:00

ok cheers, yeah after i rang up the part shop i suddenly realized if the gauge is working it should be fine!

Do you have any ideas what could be making it run rich, the smell of petrol is strong from the exhaust when running hot or cold. So i assumed it was the choke holding on thinking the engine was cold at all times.

Title: Re: Coolent Temp Sensor
Post by: rubjonny on 10 January 2011, 11:35

the coolant temp sensor for dash is separate to the one for the ecu. they may be in the same sensor housing, but internally there are 2 different sensors

Title: Re: Coolent Temp Sensor
Post by: javalin on 10 January 2011, 11:38

>So i assumed it was the choke holding on thinking the engine was cold at all times.
the "choke" is actually extra fueling (i.e. longer injector opening times) which is controlled by the ECU based on the engine temp reported by the coolant temp sensor.  As the engine warms up the fueling is decreased.  Its a single part with two temperature dependant resistors in it - one runs the dash and the other reports to the ECU.

Title: Re: Coolent Temp Sensor
Post by: wpisme823 on 10 January 2011, 11:47

thank you for the advice. (my knowledge of engines only stretches to small motorbikes!)

I will purchase the temp sensor now and see if it sorts it out.

im running at about 15mpg at all times at the moment so i am desperate to sort it out!

Cheers

Title: Re: Coolent Temp Sensor
Post by: Wayne on 10 January 2011, 12:10

Quote from: Deano2711 on 10 January 2011, 10:56

I may be wrong but I do believe the coolant temp sensor would not have anything to do with your car running rich. Also if the temp guage is working ok the sensor should be fine. 

Yes it will do in some respects as it controls the cold start map so as it warms up it cuts back the fueling

Title: Re: Coolent Temp Sensor
Post by: Bellend on 10 January 2011, 12:12

Mine was running rough. Changed the yellow coolant sensor and all is good.

However the thermostat has gone now I'm driving it. So on a run it cools down and it runs dodgy until it sits at the same temperature for a while.

I'd change it, they aren't expensive.