Heater bypass valve

[RedMk2Gti]

Any one know if our Australia released Mk2 Golf has heater bypass valve ?

I'm still trying to trace down why my heater has no hot air, read some thread in oversea Golf forum, one possibility is heater bypass valve playing up. But I can not see any valve in my Golf heater in/out pipes.

[syncro]

They don't have one. These are only on Golf 1s.

[mrgolf]

More likely to be gunked up heater matrix. Common flaw, and factory recall in the Mk2... What year???

[RedMk2Gti]

It is 90 built, 91 registered. I don't know if it has been covered by the recall. The heater stopped working after I flushed the coolant with running tap water through the expansion tank. I'll try disconnect the in/out hose this w/e and see if water can flow through the matrix.

[syncro]

More likely to be gunked up heater matrix. Common flaw, and factory recall in the Mk2... What year???

The factory recall was to protect against leaks burning the driver's legs.

[moto]

The coolant flows through the matrix continuously in the Mk11. That is, if it were blocked then you would have a serious overheating in the engine, not only in the heater. The heater cores are starting to fail from age but if that goes, you get coolant in the car, steam inside your windows and, again, engine overheating from loss of coolant.

If your engine isn't overheating then its possible its running cold - thermostat stuck wide open? Otherwise, its almost certainly got to be a problem in the heater unit itself, fan, flaps, vacuume ... that sort of area.

[RedMk2Gti]

Thanks, Moto

Thermostat was replaced 6 months ago, unlikely it is bad.
No overheat problem
No coolant in the car
No steam inside the window

Probably need to pull the dash out to check the heater box

[Golf Loon]

I reckon it will be the flap controlled by the cable, that is not letting hot air into the car. Check your sliding heater switches and then up under the dash to see if the heater flap is being opened.

[mrgolf]

The coolant flows through the matrix continuously in the Mk11. That is, if it were blocked then you would have a serious overheating in the engine, not only in the heater.

Oh yeah, forgot that bit...

[syncro]

I reckon it will be the flap controlled by the cable, that is not letting hot air into the car. Check your sliding heater switches and then up under the dash to see if the heater flap is being opened.

That's what it sounds like to me.