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Old 5th February 2020, 15:31   #1
Roverguest
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Unhappy 2.5 V6 heater problem hot>cold>hot

Hi,

On the V6 Rover 75, the heater has started going cold, and on investigation it appears (could be coincidence) that when accelerating it warms up, and at times gets nice and hot for a time before going cold again.

Initially I thought perhaps a stuck thermostat but doing the diagnostic shows and engine temperature as I was test driving around local roads around 100 degrees, certainly plenty for a toasty heater.

Coolant level is fine

Thanks in advance
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Old 5th February 2020, 15:37   #2
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You have an airlock in the system, have a search on here for the correct procedure for refilling the system, this should sort your issue.


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Old 5th February 2020, 15:40   #3
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Would that be likely despite the car not having had any work done since buying it last week? (when the heaters were fine)
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Old 5th February 2020, 15:47   #4
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Yes, if it hasn’t been done correctly then it will keep happening until resolved I’m afraid.


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Old 5th February 2020, 16:18   #5
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Coolant level is same as it was on picking up the car.
Would air only get in with a leak ?
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Old 5th February 2020, 17:28   #6
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Quote:
Originally Posted by Roverguest View Post
Coolant level is same as it was on picking up the car.

Would air only get in with a leak ?


No! The coolant level will remain the same with an airlock, the coolant won’t be circulating around the whole system properly.




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Old 5th February 2020, 19:11   #7
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On a side note, It’s a 02 reg, and I think a 3 speed fan as no visible relay, but no fan kick in until coolant reaches 112 on the diagnostics on IPK.

Fan works with AC

What would this indicate?
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Old 5th February 2020, 19:17   #8
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Quote:
Originally Posted by Roverguest View Post
On a side note, It’s a 02 reg, and I think a 3 speed fan as no visible relay, but no fan kick in until coolant reaches 112 on the diagnostics on IPK.



Fan works with AC



What would this indicate?


Sounds like your low speed is dead too, this needs sorting as it could lead to other issues if left.
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Old 6th February 2020, 08:34   #9
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Quote:
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... and I think a 3 speed fan as no visible relay ..
David, your profile says that you have a 1.8T engine but you are definitely asking about a KV6? Please confirm. By the way, it's not a relay it's a resistor.
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... but no fan kick in until coolant reaches 112 on the diagnostics on IPK.
As Trikey says that usually means low speed failure, or in the case of a 3 speed fan low and medium speed failure, which you should repair immediately. This will involve removing the front bumper.
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Fan works with AC
  1. Start the engine from cold.
  2. Press the windscreen demist button.
  3. Get out of the car and walk to the radiator grille.
  4. Is the radiator fan running continuously or is it pulsing on and off periodically?

Please report back asap.

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Last edited by SD1too; 6th February 2020 at 08:40..
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Old 6th February 2020, 12:10   #10
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Quote:
Originally Posted by Roverguest View Post
Hi,

On the V6 Rover 75, the heater has started going cold, and on investigation it appears (could be coincidence) that when accelerating it warms up, and at times gets nice and hot for a time before going cold again.

Initially I thought perhaps a stuck thermostat but doing the diagnostic shows and engine temperature as I was test driving around local roads around 100 degrees, certainly plenty for a toasty heater.

Coolant level is fine

Thanks in advance
hi if all else fails this is what i done

rob
https://the75andztclub.co.uk/forum/s...d.php?t=301860
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