Hot and cold

[MattWilde 10]

now the winter is setting in i have started to use my heater and it's acting a little odd. It blows out warm air super quick, i mean it's heating up in a couple of mins but after about 10-15 mins of it on full heat the air just turns cold no matter what setting the heater dial is on. oh, and the passenger carpet isn't wet. any ideas?

[Kevin Bacon 5]

Possibly an air lock in the matrix....or, look at the two pipes that connect to the matrix on the bulkhead and see if there is a bypass valve, it might be closed.

[belfastfumanchu 0]

Sounds like same prob I have.

[P2daz 0]

Sounds like the bypass valve to me, changed mine and its fine now

[CorradoVR6-Turbo 0]

What's your temp gauge reading when this happens?

[Andy665 0]

Is the bypass valve easy enough to get to

[CorradoVR6-Turbo 0]

yes,its just before the pipes go into the bulkhead.

[belfastfumanchu 0]

My temp gages are all normal. 90 - 110 depending on moving or if in traffic if I remember correctly.

 

Will check that bypass valve

 

Does anybody have a pic of it by any chance....

[Supercharged 2]

They are metal and go inline in the hoses leading to the matrix...

 

Problem is I'm not sure you can get them anymore so the fix would be to replace with mk3 matrix and 2 new pipes...

[P2daz 0]

I got one from the stealers a few weeks ago , around £30

[dr_mat 0]

Later heater matrix parts have the bypass valve integrated into the matrix itself, there's no need for one inline on the hoses.

[belfastfumanchu 0]

Does the bypass valve have two little arrows on it? One pointing up and one pointing down?

 

Also is it just a matter of taking it off and putting the new one on....a 10 min job in theory or is there more to it.

[woody 0]

it took JMR about an hour to do on my car. as the jubille clips were all seized. Also he flushed out the whole system by leaving the bottm coolant pipe off and attached the garden hose to the top of the expansion tank using a nifty connector which fitted the tank turned the water on at full pelt and i was amazed what c**p came out (sludge). The whole heater system worked so much better after that.

Cheers

Woody

[belfastfumanchu 0]

Heres a pic of a brand new bypass valve. Its fited to the coolant pipes just before they pass through the bukhead. Theres a couple of arrows on the metal part of it.