heater temp.

[jod]

My golf mk2 gti heater is getting tempremental.The heater gets nice and warm when it reaches temp but when the blower is turned on the temp drops and goes cool,no obvious leaks and no air in the system,however no air bleed screw is in line.
Any advice would be appreciated.

[DeltaFox]

Possible blocked heater matrix.

Oh could also be one of the control cables is detached/clip broken,had this problem myself.


>> Edited by DeltaFox on Saturday 9th April 22:43

[iguana]

DeltaFox said:

Possible blocked heater matrix.

Yip Ive had the same- same symptoms ona couple of Mk2s, fiddly feckers to replace.

How the coolant tempo tho? its its dead low it may be a faulty thermostat.

[anonymous-user]

Sounds like it could be the pressure bypass valves that go between the two coolant pipes leading to the heater matrix.

If that is what it is, they've been deleted by VW recently. You might be able to find one or two left. Otherwise, you can just replace them with a bit of pipe.

If it's the matrix, I believe that the VW parts catalogue now shows the Mk3 as a direct replacement for the Mk2 item with the advantage that this one didn't suffer from the bursting that required them to fit the bypass valves in the first place.

[iguana]

LexSport said:

Sounds like it could be the pressure bypass valves that go between the two coolant pipes leading to the heater matrix.

I dont think he'd have any heat if it were those little buggers tho.

[anonymous-user]

iguana said:

LexSport said: Sounds like it could be the pressure bypass valves that go between the two coolant pipes leading to the heater matrix. I dont think he'd have any heat if it were those little buggers tho.

Not sure, I have similar symptoms on mine and I'm sure it's the valves. Have got new ones, just haven't fitted them yet. My theory is that there's a small enough flow into the heater matrix to heat it up to begin with but once there's a flow of air from the blower it cools the matrix.

[iguana]

Lexsport- maybe, I had thought the valves when closed cut off flow totally tho.

I've had a nightmere bleeding through the system with those valves before, did the Golf which has no valves- all hoses off & full rad & engine & matrix flush through & refill with new antifreeze & all done in 20ish mins, on Corrado with the valves it took all soddin' afternoon to get an airlock out of the matrix! coz of the little feckers!

[anonymous-user]

Hmmm, could be just a big airlock. I'll get around to changing mine soon to find out. Out of interest, what did you do to bleed the 'Rado's system?

Sorry for the thread hijack!

[iguana]

LexSport said:

Hmmm, could be just a big airlock. I'll get around to changing mine soon to find out. Out of interest, what did you do to bleed the 'Rado's system? Sorry for the thread hijack!

Blimey now you are asking, err i tried all sorts! inc many more flushes & valves off in cleaned etc & whatever I did I seemed to get hot water to the heater but no water flow through,

Think what did it finally was squshing the pipe on the heater side where it was hot on heater side but cool on engine side (thus I assume was the return) then feeling pressure build right up & burning my hand! then releasing, did that afew times & seemed to do the trick!, 6 months on of winter running & no issues.