Golf Heater Problems - leerance
I have a MK2 golf and I can not get the heater working. I have flushed and back flushed the heater matrix, I have also drained and refilled the cooling system several times. Once the engine is at it normal temperature, if I then hold the hoses running into the heater matrix, the incoming hoses is red hot, there is a thin bypass hoses which is also red hot. Beyond the bypass hoses incoming is warm, the outgoing hoses is cold until the point were the small bypass hoses joins, were it becomes red hot again. So the hot water does not appear to be flowing around the heater matrix. When I first turn the heater on it will blow out warm air and after 5 minutes will go completely cold. I have checked the air flaps and these seem to be working correctly and I have checked the thermostat and this is working, apart from this the cooling system seems to be working correctly as the car does not overheat. Does anyone know what else I can try?
Golf Heater Problems - Mark S
Sounds like car has had VW recall mod to heater:this involed fitting two valves to heater hoses near bulkhead.Over time these can get bunged up or stop working:the silver coloured valve has a wax module in it.Remove & clean,pay attention to small hose & outlet for it.If still not working go to VW dealers,part with about £30 for new valve kit.Do not leave valves off as they are there to stop heater rad blowing up!
Golf Heater Problems - Arch Stanton
I left my MKII Jetta into a VW dealership last week for the heater matrix recall (several years late). Now, the heater only blows out cold air! Didn't notice it not working, but then it hasn't been cold until today. Obviously something's gone wrong but have they cocked it up or is it an unhappy coincidence? Worked fine before I left it in.
Golf Heater Problems - Treeman
I have had exactly the same problem! I have taken off the inlet flow/pressure restrictor modification and flushed it out and I have also taken off the black plastic? outlet modification and the non-return valve is working OK.I think what is happening is that the flow past the restrictor is not enough to push the air past the non-return valve on the outlet and so you get an air lock in the heater matrix. How you solve this I'm not sure, I have tried several things but just end up with hot anti-freeze mixture all over the place!
Have you solved this yet, leerance.
Golf Heater Problems - spoiler
Did the recall affect all Mk2 golf's, or did they resolve this on later models before they went out?
Golf Heater Problems - Treeman
In case anyone has similar problems.I purchased a new modification kit (£40 with VAT) and fitted it. The car heater now works fine. When the device is working properly the small bypass pipe should not get hot. Being curious I broke open the old inlet valve to have a look. When the car overheats a spring actuates a plug which restricts the flow to the car heater matrix and coolant flows through the bypass pipe. This operation is not reversible so every time the car overheats you have to install a new mod kit.
Golf Heater Problems - tonyh
leerance On my sons golf we removed the heater hose (when cold) and topped up the pipe with water, this cured a no heat problem he had HTH tonyh
Golf Heater Problems - woods
my heater worked fine on my passat until I added Holts Radweld, after one day the heater suffered the normal temp/cold heater problem. I've tried flushing it but it has made no difference and I don't fancy paying £39 for a new valve, anyone else had a problem with VW/Radweld?
Golf Heater Problems - simonsmith473©
When you first add radweld i think you are supposed to run the car with the heater blowing hot, otherwise problems can be suffered with the matrix or so i've heard.
Golf Heater Problems - Big John
You have to be careful when using Radweld, It does what it says on the tin. It will solidify when coolant is exposed to air, this includes air locks in the heater matrix!!
If you ever use it you must ensure the system is free from any air pockets. Afterwards you should drain, flush! and refill the cooling system.

Once the heater matrix is blocked with radweld youve had it, it will need replacing. I speak from past bitter experience.
Golf Heater Problems - simonsmith473©
After adding radweld leave the cap off the expansion tank and have the heater blowing hot until the engine is hot, this will bleed the cooling system and stop airlocks.


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