Temp Gauge at max but no coolant issues

Polox · 8th January 2021, 19:09

Hi.
Cannot find exact answer on this forum but I assume it will be a sensor issue but would appreciate confirmation. Vehicle MK II 2004 KV6 Rover 75.
Current problem is that after starting from cold after after say few minutes fan goes to high speed temp gauge rises rapidly to maximum setting with the red light on and air conditioning fails to work. Under bonnet check shows normal coolant levels. Fan continues to run at high speed for a few minutes when ignition turned off.
Appreciate any comments as to the exact problem I am having.
Regards
Jeffrey - Sunshine Coast,Queensland, Australia.

suzublu · 8th January 2021, 19:38

Perhaps the resistor has failed or the slow speed fan. Turn the A/C off, start the car, press demist button to see if the fan runs.

BOZZ · 8th January 2021, 19:48

Quote:

Originally Posted by Polox

Hi.
Cannot find exact answer on this forum but I assume it will be a sensor issue but would appreciate confirmation. Vehicle MK II 2004 KV6 Rover 75.
Current problem is that after starting from cold after after say few minutes fan goes to high speed temp gauge rises rapidly to maximum setting with the red light on and air conditioning fails to work. Under bonnet check shows normal coolant levels. Fan continues to run at high speed for a few minutes when ignition turned off.
Appreciate any comments as to the exact problem I am having.
Regards
Jeffrey - Sunshine Coast,Queensland, Australia.

What about digital temperature on your dash ? What temperature is show?
But I do think it is sensor.Good luck.

vitesse · 8th January 2021, 21:19

You asked about Toaf when you had your airbag issue, fixed? If you've got it then test the fan speeds with that. But no air-con does point to a fan issue, and as above check the actual temperature with the onboard diagnostics.

Regards

Polox · 8th January 2021, 22:47

Thanks for replies. I had replaced original resistor with a new gold one from Jules about 2 years ago. When starting the fan runs at normal speed and air conditioning works. But after about 2 mins fan speed increases and air conditioning ceases to work.Then temp gauge climbs rapidly to max setting. Say after engine off for about 30mins everything back to normal when starting but then after about 2 minutes same thing happens? I am not losing a drop of coolant. New water pump, thermostat about 2 years ago.

kaiser · 9th January 2021, 03:20

Sounds like a stuck thermostat.

stocktake · 9th January 2021, 13:45

What temperature does the on board diagnostics show?

T-Cut · 9th January 2021, 20:37

The gauge reading and red light indicate the overheat is real. A loss of sensor signal gives everything you describe except for the gauge response, which points south. Such a rapid overheat (2 minutes from cold) indicates something other than a cooling fan issue. I think you'll get the logical high readings from the diagostic routine. Whether a KV6 with a failed thermostat will overheat in just two minutes I don't know. Maybe water pump impellors actually do drop off?

TC

Polox · 10th January 2021, 02:01

Sunday Jan 10th Diagnostic test.
Started from cold. All good for about 3 mins. temp gets to 108 and high speed fan kicks in. Temp goes to 123 and gauge is now at 12oclock position with red light on. Stop engine and fan runs at high speed for say 60 secs. Coolant levels all good. What is the prognosis?

Polox · 10th January 2021, 04:21

Just thought I would also add that I had put in a new thermostat and water pump just over 2 years ago and have only travelled about 20,000 kms since then. Hence I am a bit skeptical about a thermostat or water pump problem.

8th January 2021, 19:09	#1
Polox Regular poster 2001 and 2004 Rover 75's Join Date: Jun 2018 Location: Buderim QLD Posts: 47 Thanks: 18 Thanked 3 Times in 2 Posts	Temp Gauge at max but no coolant issues Hi. Cannot find exact answer on this forum but I assume it will be a sensor issue but would appreciate confirmation. Vehicle MK II 2004 KV6 Rover 75. Current problem is that after starting from cold after after say few minutes fan goes to high speed temp gauge rises rapidly to maximum setting with the red light on and air conditioning fails to work. Under bonnet check shows normal coolant levels. Fan continues to run at high speed for a few minutes when ignition turned off. Appreciate any comments as to the exact problem I am having. Regards Jeffrey - Sunshine Coast,Queensland, Australia.

8th January 2021, 22:47	#5
Polox Regular poster 2001 and 2004 Rover 75's Join Date: Jun 2018 Location: Buderim QLD Posts: 47 Thanks: 18 Thanked 3 Times in 2 Posts	Temp Gauge at max but no coolant issues Thanks for replies. I had replaced original resistor with a new gold one from Jules about 2 years ago. When starting the fan runs at normal speed and air conditioning works. But after about 2 mins fan speed increases and air conditioning ceases to work.Then temp gauge climbs rapidly to max setting. Say after engine off for about 30mins everything back to normal when starting but then after about 2 minutes same thing happens? I am not losing a drop of coolant. New water pump, thermostat about 2 years ago.

9th January 2021, 03:20	#6
kaiser This is my second home 75 Tourer 2.5 Auto, 1.8T, 75V8ZT Join Date: Jun 2007 Location: Johannesburg ZA Posts: 6,200 Thanks: 1 Thanked 859 Times in 613 Posts	Sounds like a stuck thermostat. __________________ Worth his V8 in gold

9th January 2021, 13:45	#7
stocktake Vis Whiz Rover 75 2.5 auto Saloon Join Date: Jun 2007 Location: LEEDS Posts: 20,587 Thanks: 2,057 Thanked 3,056 Times in 1,621 Posts	What temperature does the on board diagnostics show? __________________ Dave... Lost a few stones and a Gall Bladder and part of a bile duct and all of my dignity in the suppository incident

8th January 2021, 19:38	#2
suzublu This is my second home rover 75 1.8 vvc club se wedgwood blue Join Date: Aug 2009 Location: Seaton Carew Posts: 26,920 Thanks: 65 Thanked 7,142 Times in 4,642 Posts	Perhaps the resistor has failed or the slow speed fan. Turn the A/C off, start the car, press demist button to see if the fan runs.

8th January 2021, 21:19	#4
vitesse I really should get out more....... Rover 75 Saloon Join Date: Jul 2011 Location: Gävle Posts: 2,533 Thanks: 395 Thanked 823 Times in 652 Posts	You asked about Toaf when you had your airbag issue, fixed? If you've got it then test the fan speeds with that. But no air-con does point to a fan issue, and as above check the actual temperature with the onboard diagnostics. Regards

9th January 2021, 20:37	#8
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,753 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	The gauge reading and red light indicate the overheat is real. A loss of sensor signal gives everything you describe except for the gauge response, which points south. Such a rapid overheat (2 minutes from cold) indicates something other than a cooling fan issue. I think you'll get the logical high readings from the diagostic routine. Whether a KV6 with a failed thermostat will overheat in just two minutes I don't know. Maybe water pump impellors actually do drop off? TC

10th January 2021, 02:01	#9
Polox Regular poster 2001 and 2004 Rover 75's Join Date: Jun 2018 Location: Buderim QLD Posts: 47 Thanks: 18 Thanked 3 Times in 2 Posts	Sunday Jan 10th Diagnostic test. Started from cold. All good for about 3 mins. temp gets to 108 and high speed fan kicks in. Temp goes to 123 and gauge is now at 12oclock position with red light on. Stop engine and fan runs at high speed for say 60 secs. Coolant levels all good. What is the prognosis?

10th January 2021, 04:21	#10
Polox Regular poster 2001 and 2004 Rover 75's Join Date: Jun 2018 Location: Buderim QLD Posts: 47 Thanks: 18 Thanked 3 Times in 2 Posts	Just thought I would also add that I had put in a new thermostat and water pump just over 2 years ago and have only travelled about 20,000 kms since then. Hence I am a bit skeptical about a thermostat or water pump problem.