No Cabin Heat from Heater Vents

4.2 V8 32v Naturally Aspirated - 414 bhp
Post Reply
User avatar
jamiej
2nd Gear
Posts: 204
Joined: Tue Apr 03, 2018 4:06 pm

No Cabin Heat from Heater Vents

Post by jamiej » Mon Mar 13, 2023 11:10 am

Hi all,

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

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.
:thumbs:
Current
'07 - Audi RS4 Avant Daytona Grey
'16 - BMW M135i F20 (LCI)
Gone
'02 Audi 8L A3 1.9 TDI (PD)
'03 Subaru Impreza WRX STI
'96 VW Golf VR6
'91 Toyota MR2 NA
'90 Peugeot 205 GTI 1.9
'90 VW Mk2 Golf GTI 8V

User avatar
Dubbsley
1st Gear
Posts: 50
Joined: Fri Apr 08, 2022 7:00 pm

Re: No Cabin Heat from Heater Vents

Post by Dubbsley » Mon Mar 13, 2023 7:59 pm

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.


Sent from my iPhone using Tapatalk

User avatar
Dubbsley
1st Gear
Posts: 50
Joined: Fri Apr 08, 2022 7:00 pm

Re: No Cabin Heat from Heater Vents

Post by Dubbsley » Mon Mar 13, 2023 8:06 pm

Dubbsley wrote: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)

Sent from my iPhone using Tapatalk

Sent from my iPhone using Tapatalk

User avatar
jamiej
2nd Gear
Posts: 204
Joined: Tue Apr 03, 2018 4:06 pm

Re: No Cabin Heat from Heater Vents

Post by jamiej » Mon Mar 13, 2023 9:03 pm

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.

Sent from my ONEPLUS A6013 using Tapatalk


Current
'07 - Audi RS4 Avant Daytona Grey
'16 - BMW M135i F20 (LCI)
Gone
'02 Audi 8L A3 1.9 TDI (PD)
'03 Subaru Impreza WRX STI
'96 VW Golf VR6
'91 Toyota MR2 NA
'90 Peugeot 205 GTI 1.9
'90 VW Mk2 Golf GTI 8V

User avatar
Dubbsley
1st Gear
Posts: 50
Joined: Fri Apr 08, 2022 7:00 pm

Re: No Cabin Heat from Heater Vents

Post by Dubbsley » Mon Mar 13, 2023 9:12 pm

jamiej wrote: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.

Sent from my ONEPLUS A6013 using Tapatalk
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.


Sent from my iPhone using Tapatalk

User avatar
jamiej
2nd Gear
Posts: 204
Joined: Tue Apr 03, 2018 4:06 pm

Re: No Cabin Heat from Heater Vents

Post by jamiej » Thu Mar 16, 2023 9:41 am

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.ImageImage

Sent from my ONEPLUS A6013 using Tapatalk
Last edited by jamiej on Thu Mar 16, 2023 9:48 am, edited 1 time in total.
Current
'07 - Audi RS4 Avant Daytona Grey
'16 - BMW M135i F20 (LCI)
Gone
'02 Audi 8L A3 1.9 TDI (PD)
'03 Subaru Impreza WRX STI
'96 VW Golf VR6
'91 Toyota MR2 NA
'90 Peugeot 205 GTI 1.9
'90 VW Mk2 Golf GTI 8V

User avatar
jamiej
2nd Gear
Posts: 204
Joined: Tue Apr 03, 2018 4:06 pm

Re: No Cabin Heat from Heater Vents

Post by jamiej » Thu Mar 16, 2023 5:25 pm

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

Sent from my ONEPLUS A6013 using Tapatalk

Current
'07 - Audi RS4 Avant Daytona Grey
'16 - BMW M135i F20 (LCI)
Gone
'02 Audi 8L A3 1.9 TDI (PD)
'03 Subaru Impreza WRX STI
'96 VW Golf VR6
'91 Toyota MR2 NA
'90 Peugeot 205 GTI 1.9
'90 VW Mk2 Golf GTI 8V

User avatar
jamiej
2nd Gear
Posts: 204
Joined: Tue Apr 03, 2018 4:06 pm

Re: No Cabin Heat from Heater Vents

Post by jamiej » Wed Nov 29, 2023 4:52 pm

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!

Sent from my CPH2415 using Tapatalk

Current
'07 - Audi RS4 Avant Daytona Grey
'16 - BMW M135i F20 (LCI)
Gone
'02 Audi 8L A3 1.9 TDI (PD)
'03 Subaru Impreza WRX STI
'96 VW Golf VR6
'91 Toyota MR2 NA
'90 Peugeot 205 GTI 1.9
'90 VW Mk2 Golf GTI 8V

Post Reply

Return to “RS4 (B7 Typ 8E) 2006–2008”

Who is online

Users browsing this forum: Google [Bot] and 549 guests