Heater only getting warm in my RS2

[Golfboy666GTI]

This winter (here in New Zealand) my heater seems to have almost stopped working.
It used to get so hot you could almost burn your hand on the air vents, now it only gets luke warm when on full.
Does anyone know what could have gone wrong and how I repair it?

[UrS4boy]

Nik: Not sure how the B4 avant chassis heater system works (or whether all RS2s have automatic climate control) BUT... I can tell you that I had the same problem with my 98 C4 A6 avant (with autoclimate control) after I did the heater core (matrix) replacement. Turns out that the control arm between the temp flap and the temp flap servo motor came loose when I reassembed things. The solution was to take things a bit apart and reconnect that arm to the servo.

More later. Have to go eat supper/dinner/evening meal/.

[Golfboy666GTI]

Nik: Not sure how the B4 avant chassis heater system works (or whether all RS2s have automatic climate control) BUT... I can tell you that I had the same problem with my 98 C4 A6 avant (with autoclimate control) after I did the heater core (matrix) replacement. Turns out that the control arm between the temp flap and the temp flap servo motor came loose when I reassembed things. The solution was to take things a bit apart and reconnect that arm to the servo.

More later. Have to go eat supper/dinner/evening meal/.

RHD RS2's only have standard A/C, no climate control.

[UrS4boy]

RHD RS2's only have standard A/C, no climate control.

Hmm..sorry, then I've got nothing. Check your email Nik. I sent you a prezzy anyway (you probably have it but....)

[Veg]

Is the car getting up to temperature? Mine didn't and was freezing.....stuck thermostat.....

[johne]

Could be a few things, does the heater warm up if you raise the RPM and keep them above say 3500?

Winter in NZ , I left Auckland on Monday having just been round the south island and your great summer was extending so winter hadn't really arrived yet!!!

John

[80Quattro]

It's been 22 and 0 today here on the Canterbury plains, it's like all the seasons in one day. That doesn't help much with your problem other than to add that you really do need a heater here!

Is the temperature gauge still reading around 90? If it is then I would suspect the blender flap has become misaligned or you heater matrix has become blocked.

[Colesy]

An airlock could possibly cause this. Might be worth checking coolant levels and bleeding the system.

[Golfboy666GTI]

Is the car getting up to temperature? Mine didn't and was freezing.....stuck thermostat.....

Hi, yip, she gets up to temp.

[Rusty]

Air lock or the heater box isn't diverting air correctly, either due to the flaps getting stuck or the foam that seals them being worn out.

[Golfboy666GTI]

Air lock or the heater box isn't diverting air correctly, either due to the flaps getting stuck or the foam that seals them being worn out.

Is it easy to access the heater box on a RHD car? Please tell me its not a dash out job.

[Golfboy666GTI]

Could be a few things, does the heater warm up if you raise the RPM and keep them above say 3500?

Winter in NZ , I left Auckland on Monday having just been round the south island and your great summer was extending so winter hadn't really arrived yet!!!

John

I have had that, heater getting hotter at higher rpm.

[UrS4boy]

I have had that, heater getting hotter at higher rpm.

But what is you coolant temp gauge reading? As suggested, the thermostat might have failed open.

With the UrS4/S6s, the issue is the brass loop that holds the spring breaks off the thermostat body, leaving the thermostat failed open.

This would be the one on the left (V6 one on the right)

[quattro-nick]

I'm almost pretty sure that your heating radiator is clogged inside
remove the two lines and flush the radiator along two sides with a garden hose
put the lines back ,refull the coolantsystem and put some coolantflush or soda to your coolantsystem
ride for a while and see if the heater is improved
afterwords,remove coolant and flush the engine good with a gardenhose(take a few waterlines loose) to be sure that everything is cleaned and put some new coolant on the system.
i hope this is your solution
good luck

[johne]

LHD or RHD, replacing the heater matrix is a dashboard out job. S2Central on here did a "how to" guide.

Given your heat output increases with RPM, that suggests a partially blocked heater matrix or an air lock.

As suggested above, flushing the matrix is the first thing to do.

Doing that will give you an air-lock anyway so you'll have to bleed the system using the little tap in one of the heater hoses. My tip here would be top-up the system after you've reconnected the heater hoses and gently blow into the radiator expansion tank (system cool of course!) whilst undoing the bleed tap. Make sure you close the bled tap before you stop blowing and don't let anyone catch you doing it

There may well be some air still in the matrix but sustained high RPM will move that through - i.e. take the car out and give it a good thrashing........not a hard thing to do but your 100KPH speed limit everywhere is a challenge.

Note of caution; you may have gained your air lock in the first place as a consequence of your matrix starting to leak. They tend to only start leaking in a very small way and the tell-tale signs are the windscreen steaming up with a slightly oily film and the hint of the characteristic smell of antifreeze in the car. I was in denial for 12 months that mine was leaking before I gave in and changed it.

Only wish it had been last weekend and I'd been able to help you.

John