Author Topic: Heat coming from interior vents while heater and AC are off.  (Read 961 times)

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Offline hjm3251

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Hello,

First off I'm new to the forum so a warm hello to everyone and to the admin, thank you for approving my account.

I have a minor issue with my 1.3l 2009 M2, as recently as a couple of weeks ago I have noticed heat coming from the vents in my car even though I have both the heater and AC off. At first, being somewhat of a mechanical novice, I feared that the engine must have developed a fault and was overheating or perhaps the fan was not kicking in and that was causing the engine to overheat more than usual. However having now borrowed my friends ECU reader and having it come up blank for faults, and also checking the fan sensor and its electricity supply I no longer believe this to be the case. I have also seen no sign of the hot engine light on my dash while driving. I'm just very tentative with the car and I jump to worst case scenario.

However I am all but certain this heat wasn't being produced before more than a couple of weeks ago and I've had the car coming up to 6 months now so I feel I would have noticed it earlier if it had. I'm not a particularly aggressive driver but recently I have been revving it a bit higher than usual, but no more than 3500rpm and probably 90% of the time no higher than 3 thou. So I can't say I'd expect this kind of rpm range to be especially taxing.

The car is currently at about 31k miles, 2009, 1.3l, and when the AC is on it still immediately produces cold air. Any and all input on this subject would be greatly appreciated. I don't believe the problem to be particularly worrying but it irritates me when I can't find an explanation for something.

Thanks,

Henry M

Offline Souper

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Re: Heat coming from interior vents while heater and AC are off.
« Reply #1 on: May 28, 2017, 09:31:02 AM »
Does it get hotter progressively as you turn the heater up?

Offline hjm3251

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Re: Heat coming from interior vents while heater and AC are off.
« Reply #2 on: May 28, 2017, 04:46:40 PM »
I haven't actually checked, as the past couple of days it has been quite nice weather I haven't needed it but I'd imagine so. The heater can get quite toasty when I bump it up to max and the mysterious heat doesn't feel so much like its being blown through the vents, more just flowing through.

Offline hjm3251

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Re: Heat coming from interior vents while heater and AC are off.
« Reply #3 on: June 03, 2017, 08:38:10 PM »
UPDATE:

With the help of a friend I've now witnessed the fan kick in so I am no longer concerned about that, and after fiddling with the interior heating settings I've discovered the heat only appears on certain settings. I suspect a valve of sorts that is not closing properly, either way it's clearly nothing to do with the engine.

Mazda 2 Forums UK

Re: Heat coming from interior vents while heater and AC are off.
« Reply #3 on: June 03, 2017, 08:38:10 PM »