No Cabin Heat from Heater Vents

[jamiej]

Hi all,

After years of trouble free motoring, my B7 RS4 has developed an irritating problem.

With the car up to temp and a demand for hot air in the cabin, there is no heat from the interior vents. Its cold, really cold (but I guess the ambient outside has been quite cold recently).

I've tried all sorts of settings (Auto, Hi, Demist etc. etc.) but nothing seems to make the cabin air vents blow hot air.

Car runs fine. Gets to temp and stays at the right temp without issue.

Coolant level is bang on.

My (inexpensive) OBDII reader is not throwing any codes.


I am going to pull back the top hose on the heater matrix feed from the engine bay to expose the air bleed to see if that sorts the issue, but both the inlet and outlet to the heater matrix (from the engine bay) feel hot, so I am assuming this is flowing as it should.

Whilst I wait for the hose clip remover to arrive (these clamps look to have not moved since new) can anyone suggest any other checks to see what may be causing the issue. I am hoping to tackle this job in a day, before having to resort to taking it to a garage



Thanks all, for reference Avant '07 B7 RS4 UKRHD.

[Dubbsley]

I had a very similar thing recently, turned out to be a control valve on the side of the control panel (glove box out job) didn’t show any faults, it was only when trying to control it via VCDS that it was found. I’ll try & find the paperwork with part number.


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[Dubbsley]

I had a very similar thing recently, turned out to be a control valve on the side of the control panel (glove box out job) didn’t show any faults, it was only when trying to control it via VCDS that it was found.

De-mister flap 8E2820511G (£182 +VAT)

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[jamiej]

Oooh. This looks very interesting. Thank you. I'll keep that in mind.

Presumably your problem was not just when demisting, but any demand for heat in the cabin.

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[Dubbsley]

Oooh. This looks very interesting. Thank you. I'll keep that in mind.

Presumably your problem was not just when demisting, but any demand for heat in the cabin.

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Yea there was no air flow into the cabin unless driving & then it was only minimal, the temperature again was minimal & uneven across all vents.


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[jamiej]

I've removed the glove box and had a little look.

I cannot seem to make the motor circled blue to move. But that may be because the car was not up to temp.

What's concerned me a little, is the large important looking clip (circled in blue) which isn't attached to anything. any ideas? Could this be for a now removed CD changer?

I do have an AMI box within the glove box (where the changer would've been) which I removed.

The beige connector was attached to the glove box.

Lastly, there's a strange metal box with a terminator style chip poking out of it (circled yellow). Any ideas on what this is?

Thanks all.

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[jamiej]

It's the yellow armed stepper motor on the UK Drivers side.

Looks an absolute nightmare to get to

Any bright ideas as to how to tackle this?

Thank you,
Jamie

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[jamiej]

New motor solved this.

Was charged 1.5 hours labour. It's a pig of a job.

Motor was about £200 though

Pleased to be warm again in the cabin!

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