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Author Topic: Coolant temp  (Read 9095 times)

Offline OllieL

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Re: Coolant temp
« Reply #30 on: January 29, 2022, 07:48:30 pm »
OBDeleven

So I normally go to live data and the select a “block” to see live data (like when I check the chain on our Tiguan TSI)

Don’t want to rush in to main thermostat if it turns out being a sensor. Interestingly fans come on within 10 seconds of car being turned on, and the needle sits just below 90. However OBDeleven shows coolant temps of around 70 degrees max


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Ollie

Offline pudding

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Re: Coolant temp
« Reply #31 on: January 31, 2022, 10:30:03 am »
If it never gets above 70, your main thermostat is indeed goosed.  The sensor could also do with replacing as they've revised it a few times over the years.  Although the sensor costs almost as much, if not more than the thermostat.....but whilst it's in bits and all that!

If the fans come on after start-up, check you haven't got climate control on 'Auto'.  Switch it to 'Eco' and they should turn off.


2007 ED30 | 2009 TDI 140 | 2016 BMW 330D

Offline OllieL

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Re: Coolant temp
« Reply #32 on: February 03, 2022, 06:03:35 pm »
Thanks for your reply.

So does not display the normal signs of thermostat failure (I’ve had 3 that did in the past).

I have a temp sensor fault code and the fans run all the time.
When the car is driving the temp will reach 90 degrees on dial (less on OBDeleven block readout) but when stationary and in the cold (with fans running) drops temp (I imagine the fans running maximally cools its).

Aircon on or off doesn’t matter.

Was hoping to rule out which sensor I needed to replace (rather than throw both at it, hence the conversation about which “block” show the temp sensor read out so I could work out which one).

I will just unplug one at a time and see which one I can unplug without gaining another fault code and work it out that way

Offline LC5F

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Re: Coolant temp
« Reply #33 on: February 03, 2022, 06:57:06 pm »
Was hoping to rule out which sensor I needed to replace (rather than throw both at it, hence the conversation about which “block” show the temp sensor read out so I could work out which one).

I will just unplug one at a time and see which one I can unplug without gaining another fault code and work it out that way

They both use the same grey sensor.
The one above the gearbox is very easy to swap out.
Logic would suggest it should be 50/50 between the 2, but by the law of sod it will be the one in the main thermostat, that is an awkward stinker of a job - if it's that one and you have any doubts at all about the main thermostat, replace that as well, make sure you get a new O-ring seal and clip for the sensor too.

Offline OllieL

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Re: Coolant temp
« Reply #34 on: February 05, 2022, 12:59:25 pm »
Was hoping to rule out which sensor I needed to replace (rather than throw both at it, hence the conversation about which “block” show the temp sensor read out so I could work out which one).

I will just unplug one at a time and see which one I can unplug without gaining another fault code and work it out that way

They both use the same grey sensor.
The one above the gearbox is very easy to swap out.
Logic would suggest it should be 50/50 between the 2, but by the law of sod it will be the one in the main thermostat, that is an awkward stinker of a job - if it's that one and you have any doubts at all about the main thermostat, replace that as well, make sure you get a new O-ring seal and clip for the sensor too.

Thanks for the info.
When I scan it comes up with sensor 2?
Do you know where I could find a diagram which would indicate which one of the 2 is sensor 2 please?

Thanks

Ollie

Offline LC5F

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Re: Coolant temp
« Reply #35 on: February 05, 2022, 02:01:54 pm »
Afraid I don't know the numbering.
I would suggest elimination - disconnect the easy to reach one above the box and scan again to see if it can still see the faulty one - if you can see it, that would suggest its the one in the main thermostat.