Bad heating on lower revs

[DeS]

Ok, so I took a trip for the ew years eve party. I was about 400km and temp. outside was about -3'C.

It looks like my heater is loosing warm coolant while driving on lover revs on motorway. Its getting cold in cabin. If I give some revs, warm is coming back.

Is it normal? Car has good thermostat, fresh matrix and it should be properly vented.

I'm thinking on changing water pump pulley to RS2 - style 26 toothed one with shorter belt, to give the pump more speed.

Maybe water pump rotor is bad?

Any suggestions?
Pawel.

[UrS6 - IamS6]

If it has climate rather than just the regular heating, I would suggest one of the stepper motors for the heating flap ?

Strip, fettle and reinstall, and should be job done.

Do a search on here for more info on this.

But wait till we see what others think, I could be wrong.

[mdz]

Sounds like water pump is giving up. Bad circulation until you rev it.

[DeS]

Its an old type climate control (3B), but it never failed and has no fault in memory

My suspicions for directed to water pump or air bubbles in matrix.

[ralleyquattro]

I have the same issue with my S2.
If I top up with fluid it helps... but then I hear water woosh sound from within the dash... how do I get rid of this air... tried all known bleeding technics.

[GazzaG60]

ive had this too. had air in system, slight leak under pressure.

[M_GORDON]

I think that RS2 waterpumpu and timing belt are decatalogated, not?

Maybe your system only have air.
Mines have too and make like yours. But today I leave some "litres" of air and now the heater works better. But not perfectly.

[DeS]

It must be air bubbles, so you all we're right. Already did some ventilation

I thought coolant reservoir is full, but it needed filling - consumed about half liter and maybe want more.

I need to get rid of those leaks in additional radiator


Cheers