My xc90 is a mobile fridge..!

Ronnie bb · Feb 2nd, 2012, 22:54

Hi, haven't posted for quite some time now but that's good because it means she ain't broken....! However the temp gauge has stopped working and the heater no longer blows hot air..
She is running fine but the wife ain't happy about the cold and has the heated seats on all the time now which is surely gonna give her piles.
Anyone have an idea as to my problem?? With car not wife....

ally · Feb 2nd, 2012, 23:51

Sounds like the thermostat is stuck open, first thing I would check with those symptoms

chb · Feb 3rd, 2012, 07:07

Three things spring to mind as possibilities:
thermostat stuck open so it takes car an age to get warm.
internal temp probe broken (shorted?)
external temp probe broken.

My best guess(and it is a guess) is that the internal temp probe has snapped and then short circuited the wires to give a very low ohm reading.

Why do I think this? well if it was thermostat then your wife would only whinge for first 4-5 miles before the car was warm anyway.

Also I had the internal thermocouple on mine fail (no circuit...infinite resistance) and the car wanted to run the heating on full all the time unless i overrode it.

The thermocouple in question is the one behind the slats near the stereo.

If not that then possibly actuators for moving from cold to hot air flow.

Check themocouple first (really good guide on here if you search).

Post back with your solution or if you need more help.

chb · Feb 3rd, 2012, 07:31

Just thinking (steady!) ... do you get a reading on the dashboard of external temp? Is this correct? There is no dash reading for internal temp. also try turning temp dials (both of them) all the way to max temp. This MAY override the car to force it to give you heat. When my thermocouple snapped and the car wanted to run hot all the time turning the dials to min forced the car to run aircon...one notch above min and it was back to the tropics as then the car used the thermocouple reading.

FXMunkee · Feb 3rd, 2012, 11:36

Unless you've got a really wierd combination of sensor faults, the symptoms point at the thermostat failing in it's open state.
This would cause the coolant to take a long time to get up to temperature (especially in this weather) hence the gauge not reading above Min and the heater not blowing warm air (as there's no heat in the coolant to exchange).

How far have you travelled with it like this? ie can you get the temperature to increase at all on a long run?

Ronnie bb · Feb 3rd, 2012, 16:01

I am getting a outside temp reading on the display and the temp gauge does move slightly if it's warm outside.
Last night on a 30 mile round trip the gauge dropped in temp rather than raised..!!
Phoned my local Volvo specialist and he seems to think thermostat stuck open too.
Booked in for Monday morning and expecting a hefty bill having read its a 8 hour job?!?!! Ouch.
Thanks for help guys , atleast it seemed like I knew what I was talking about when I phoned them..!!!! :-)

FXMunkee · Feb 3rd, 2012, 17:32

8hr job? For a thermostat!
TBH I'm new to XC90's (just acquired ours last month) but I've worked (tinkered) on many cars in the past and it has always ranged from a 10 to 30 minutes job.
It's a std component in all car cooling systems and is usually very easy to replace (due to the fact that they fail*). I can't believe that Volvo have made them that hard to fix!
I'd hope that there's been a miscommunication somewhere.

*BTW when they fail they are designed to fail "open", which is exactly what yours sounds like it has done. If they fail open, they direct the coolant flow through the radiator all the time, hence over-cooling. Failing "closed" would be bad

FXMunkee · Feb 3rd, 2012, 17:38

Just found this:-
http://www.volvoforums.org.uk/showthread.php?t=118472
Fiddly but should only be 1hr labour by the looks of it.
And quite DIYable if your that way inclined

Ronnie bb · Feb 4th, 2012, 10:25

Thanks FXMunkee, my wife is now talking to me again as it no longer seems my 40 th birthday present (wed) is gonna be a thermostat..!!!
Tbh I got the 8 hr labour from an Internet search- my mistake.
I will post the cost on Monday
Thanks everyone.

BestGear · Feb 5th, 2012, 20:58

Yeh, and hour is an easy job for a competent DIY or mechanic...

Just a shame the power steering pump is in the road...plus... the thermostat is seriously expensive for what it is.

David

Feb 2nd, 2012, 22:54	#1
Ronnie bb New Member Last Online: Oct 15th, 2016 21:57 Join Date: Sep 2010 Location: Northants	My xc90 is a mobile fridge..! Hi, haven't posted for quite some time now but that's good because it means she ain't broken....! However the temp gauge has stopped working and the heater no longer blows hot air.. She is running fine but the wife ain't happy about the cold and has the heated seats on all the time now which is surely gonna give her piles. Anyone have an idea as to my problem?? With car not wife....

Feb 3rd, 2012, 11:36	#5
FXMunkee New Member Last Online: Mar 16th, 2018 11:42 Join Date: Jan 2012 Location: Wigan	Unless you've got a really wierd combination of sensor faults, the symptoms point at the thermostat failing in it's open state. This would cause the coolant to take a long time to get up to temperature (especially in this weather) hence the gauge not reading above Min and the heater not blowing warm air (as there's no heat in the coolant to exchange). How far have you travelled with it like this? ie can you get the temperature to increase at all on a long run? Last edited by FXMunkee; Feb 3rd, 2012 at 11:37. Reason: typo

Feb 5th, 2012, 20:58	#10
BestGear Master Member Last Online: Feb 3rd, 2024 18:39 Join Date: Sep 2009 Location: Sunny Scotland	Yeh, and hour is an easy job for a competent DIY or mechanic... Just a shame the power steering pump is in the road...plus... the thermostat is seriously expensive for what it is. David __________________ My Weather Station

Feb 2nd, 2012, 23:51	#2
ally Senior Member Last Online: May 3rd, 2013 10:48 Join Date: Dec 2010 Location: .	Sounds like the thermostat is stuck open, first thing I would check with those symptoms

Feb 3rd, 2012, 07:07	#3
chb Master Member Last Online: Dec 22nd, 2023 10:53 Join Date: Dec 2006 Location: Leeds	Three things spring to mind as possibilities: thermostat stuck open so it takes car an age to get warm. internal temp probe broken (shorted?) external temp probe broken. My best guess(and it is a guess) is that the internal temp probe has snapped and then short circuited the wires to give a very low ohm reading. Why do I think this? well if it was thermostat then your wife would only whinge for first 4-5 miles before the car was warm anyway. Also I had the internal thermocouple on mine fail (no circuit...infinite resistance) and the car wanted to run the heating on full all the time unless i overrode it. The thermocouple in question is the one behind the slats near the stereo. If not that then possibly actuators for moving from cold to hot air flow. Check themocouple first (really good guide on here if you search). Post back with your solution or if you need more help.

Feb 3rd, 2012, 07:31	#4
chb Master Member Last Online: Dec 22nd, 2023 10:53 Join Date: Dec 2006 Location: Leeds	Just thinking (steady!) ... do you get a reading on the dashboard of external temp? Is this correct? There is no dash reading for internal temp. also try turning temp dials (both of them) all the way to max temp. This MAY override the car to force it to give you heat. When my thermocouple snapped and the car wanted to run hot all the time turning the dials to min forced the car to run aircon...one notch above min and it was back to the tropics as then the car used the thermocouple reading.

Feb 3rd, 2012, 16:01	#6
Ronnie bb New Member Last Online: Oct 15th, 2016 21:57 Join Date: Sep 2010 Location: Northants	I am getting a outside temp reading on the display and the temp gauge does move slightly if it's warm outside. Last night on a 30 mile round trip the gauge dropped in temp rather than raised..!! Phoned my local Volvo specialist and he seems to think thermostat stuck open too. Booked in for Monday morning and expecting a hefty bill having read its a 8 hour job?!?!! Ouch. Thanks for help guys , atleast it seemed like I knew what I was talking about when I phoned them..!!!! :-)

Feb 3rd, 2012, 17:32	#7
FXMunkee New Member Last Online: Mar 16th, 2018 11:42 Join Date: Jan 2012 Location: Wigan	8hr job? For a thermostat! TBH I'm new to XC90's (just acquired ours last month) but I've worked (tinkered) on many cars in the past and it has always ranged from a 10 to 30 minutes job. It's a std component in all car cooling systems and is usually very easy to replace (due to the fact that they fail). I can't believe that Volvo have made them that hard to fix! I'd hope that there's been a miscommunication somewhere. BTW when they fail they are designed to fail "open", which is exactly what yours sounds like it has done. If they fail open, they direct the coolant flow through the radiator all the time, hence over-cooling. Failing "closed" would be bad

Feb 3rd, 2012, 17:38	#8
FXMunkee New Member Last Online: Mar 16th, 2018 11:42 Join Date: Jan 2012 Location: Wigan	Just found this:- http://www.volvoforums.org.uk/showthread.php?t=118472 Fiddly but should only be 1hr labour by the looks of it. And quite DIYable if your that way inclined

Feb 4th, 2012, 10:25	#9
Ronnie bb New Member Last Online: Oct 15th, 2016 21:57 Join Date: Sep 2010 Location: Northants	Thanks FXMunkee, my wife is now talking to me again as it no longer seems my 40 th birthday present (wed) is gonna be a thermostat..!!! Tbh I got the 8 hr labour from an Internet search- my mistake. I will post the cost on Monday Thanks everyone.

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