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Model specific boards => Golf mk2 => Topic started by: Alec on 10 November 2009, 13:09

Title: Since new radiator, heaters aint got no heat
Post by: Alec on 10 November 2009, 13:09
Had a new radiator and now my blowers dont blow out no hot air, only really noticed it the past couple of weeks as the cold has been setting in. Are these easy to replace and plumb up? Is it possible the system just needs bleeding for them to work again?
Title: Re: Since new radiator, heaters aint got no heat
Post by: jezza16v on 10 November 2009, 13:30
An air lock is possible but unlikely, firstly check that the pipes to the heater matrix get hot where they pass through the bulkhead.
If they are not getting hot, check whether your car has the VW 'recall' heater bypass unit fitted?
If you have this unit fitted it has probably failed which means you get no heat into the car, there are a few solutions to this problem,
I just sorted mine on Sunday. Let us know what you find.
Title: Re: Since new radiator, heaters aint got no heat
Post by: nige_s on 10 November 2009, 13:34
Replace the heater bypass valve with a couple of lengths of 22mm copper pipe.  If heating is then restored the valve was faulty, you've then got two options, buy a new valve about a tenner or leave as is for more heat.  I left mine with the copper pipe installed, its a relatively new matrix and I'd rather have heat than anything tepid.  Its been like that for a couple of years now.
Title: Re: Since new radiator, heaters aint got no heat
Post by: Alec on 10 November 2009, 13:42
Heat exchanger? Wheres that. I am such a vw noob
Title: Re: Since new radiator, heaters aint got no heat
Post by: jezza16v on 10 November 2009, 14:20
The matrix/heat exchanger is behind the dash, very awkward to get to and tricky to change, that's your last resort before trying everyting else. There are two rubber pipes into it passing through the bulkhead in the engine bay just below the coil, the bypass unit is fitted between the two pipes one bit is metal the other is plastic and there is a very thin rubber hose passing between them.
Title: Re: Since new radiator, heaters aint got no heat
Post by: Alec on 10 November 2009, 15:00
Cant remember seeing that, I see the two hoses, one is a feed and the other return? One comes out the side of the block or the head doesnt it? I'll go have a proper look in a minute and see what I find
Title: Re: Since new radiator, heaters aint got no heat
Post by: nige_s on 10 November 2009, 15:16
A bit of searching would help

http://www.golfgtiforum.co.uk/index.php?topic=31666.0

All you need to know, provided your blower motor works and you car has got water in the coolant I'd hazard a guess that this is your problem!
Title: Re: Since new radiator, heaters aint got no heat
Post by: Alec on 10 November 2009, 15:40
Ah thats brilliant, got my head around it now, cheers nige, told you I was an utter noob  :smiley:
Title: Re: Since new radiator, heaters aint got no heat
Post by: nige_s on 10 November 2009, 16:01
Dropping in a bit of copper tubing should take only a few minutes, from memory there is a smaller breather pipe with a 4-5mm internal diameter, just cable tied this out of the way, it won't affect the cooling system as nothing flows through it.

The valve was installed as a recall/factory mod as there was a large batch of bad heater matrix's that burst running at higher temperatures.  The bypass valve just restricts flow to help prevent this, chances are your heater matrix has lasted this long and wasn't part of the bad batch anyway.
Title: Re: Since new radiator, heaters aint got no heat
Post by: Alec on 10 November 2009, 16:11
Ah I didnt know that, and once I have done this I just run the engine with the lid off the expansion tank for a bit and give the pipes a bit of a squeeze to let the air out?
Title: Re: Since new radiator, heaters aint got no heat
Post by: jezza16v on 10 November 2009, 17:43
Dropping in a bit of copper tubing should take only a few minutes, from memory there is a smaller breather pipe with a 4-5mm internal diameter, just cable tied this out of the way, it won't affect the cooling system as nothing flows through it.

The small dia pipe is the 'bypass' pipe, you must block this off before you tie it out of the way, you only need to replace the metal bypass unit on the heater 'flow' pipe with copper tube, the plastic bit on the return pipe is just a one way valve and can be left in place.

I didn't do the copper tube fix, I just took off the 'metal' bypass unit from the flow pipe, in one end you can see a copper coloured flat metal valve, I just drilled a 6mm hole through it flushed out the swarf and put it back with the small bypass tube left in place to take some flow away from the matrix, I guess this might keep the matrix temperature down a bit and reduce the risk of it blowing......?

I managed to do it without losing any coolant, (well only a few drops) I took the header tank off and dropped it down just below the level of heater pipes then caught the coolant from the disconnected pipes in a plastic tub, not much at all really, then poured it all back in when I'd finished.  :smug:
Title: Re: Since new radiator, heaters aint got no heat
Post by: Alec on 10 November 2009, 21:35
Sound, so instead of the copper just drill through the inside of the bypass valve? sounds a bit more tidy to be honest, I dont need the heat to melt my face off every day or owt, just enough to de-frost the windscreen and stop the girlfriend from moaning shes cold lol

Thanks for the advise everyone, much appreciated. This forum is the sh*t
Title: Re: Since new radiator, heaters aint got no heat
Post by: Thom89 on 10 November 2009, 22:03
Sound, so instead of the copper just drill through the inside of the bypass valve? sounds a bit more tidy to be honest, I dont need the heat to melt my face off every day or owt, just enough to de-frost the windscreen and stop the girlfriend from moaning shes cold lol

Thanks for the advise everyone, much appreciated. This forum is the sh*t

PMd
Thom
Title: Re: Since new radiator, heaters aint got no heat
Post by: jamrock on 10 November 2009, 23:06
the copper pipe bypass sorted my heating out :cool: