Replaced the heater core, now 1 x hose to go...

[Notchback]

New owner of MK 2 GTI here. Got excited and removed the lower parts of the dash and console to replace the heater core last week- went fine and only took about 4-5 hours all in with a thorough cleaning of all the parts.

Notes to all thinking about it- I used a new MK 3 heater core and while it does fit in the same position, it is not exactly the same as the original and the hoses will need to be attached further inside the firewall (just inside) rather than external to it. Also the sealing around the hoses will need to be addresed with some foam as the MK 3 surround and foam can not be readily used. You have been warned! I might post a picture up to explain.

Anyway I now have heat and it's all good.

Next problem- the heater hose from the cylinder head to the heater is torn / split and taped up while I scratch my head on replacing it as my car is an automatic and the hose branches off unlike the manual version which is just a straight through hose. As the hose is 90 pounds to buy out of the UK. (VW were useless here and didn't want to assist), I am wondering if i can change the hose outlet on the cylinder head to one that splits the coolant thus enabling me to plumb to the heater like a manual version and use another port from the hose outlet to plumb off to what ever else is needing the coolant (I am assuming it's a trans cooler or similar).

Anyone done this before to an automatic MK 2? If I am correct and can use other non standard but original VW parts, it will be a load cheaper than the correct 3 way hose for the automatic.

Happy to hear from those that have done this.

[rob64981]

It would be good if you could put a step by step guide to changing the heater box.
From what i have read its a common problem and lots of people will need to know how to change the heater box.
I think i read on here that a Seat heater fits as well?
Does anyone know how to do the Seat one?
Chears Rob

[Peter Jones]

You could just go to a hose place like Pirtek and get a brass T piece to tap off the other line too.

Pete

[sports racer]

There shouldn't be any problem splitting the hose outlet if you can find the bits. Many a time I've used copper pipe together with generic rubber hoses I've bought from Supercheap or Repco. Works out a lot cheaper.

Somewhere out there is an old Volvo with $18 worth of heater hoses instead of the original $114 part.

[Notchback]

Thanks for the tips on the hose. A friend in the UK struck gold and found an NOS correct auto hose for me and it's on it's way to me in Adelaide. Not cheap but the car is all original so it's worth keeping it that way.

As for the heater core replacement- it's very easy and you should definately do it as it only costs under $100 for a good heater and a bit of time. Bear in mind I am not a mechanic and I managed to do it without cocking anything up:

1- remove the console- screws either side and gearshift bits (mine is auto so you just pop up the plastic bits to find a single screw there). Easy peasy- you can even remove the console with the seats in the car if they are all the way back.
2- remove the lower dash pieces- screws either side and along the top of each piece- just look for them and within 5 minutes it's all out of the car ready for a good cleaning.
3- remove the glovebox- look for the screws including the ones under little felt plugs inside the lid- another 5 minutes there and your done. Wiggle the little light out of it without screwing it up!
4- pop the front lid and find 3 x 10mm nuts on the firewall- 2 are around the coil area (one above the other with large washers)- look and ye shall find. The other one is across from the coil- passengers side. Undo all of them and you've just spent another 5-10 minutes...
5- assuming the heater hoses are disconnected from the heater, now go back inside the car. Remove the heater slider knobs- pull the suckers out easily. Then remove the whole air control thingo by undoing more screws and it will pop out.
6- remove the central dash vents by unscrewing 2 s screws at the top and with some jiggery pokery it will come out but dont be heavy handed.
7- remove the hoses that attach to the outer vents by being reasonably forceful.
8- undo more screws as they become apparent from the plastic bits and bobs screwed to the main housing- seek them out but there aren't many.
9- I also removed the radio just because it was easy and it gave a bit more visual to what I was doing.
10- I removed the 13mm bolt in the glovebox area that secures the big black box to allow the whole she-bang to move a bit.
11- you should be about ready to wiggle the whole she bang a bit and now that it moves, get a screw driver and pry the metal clips off from all around the 2 x housings- they fling off everywhere if your not careful.
12- your basicaly done now, man handle all the plastic crap out of the way and find the heater core. Remove it, throw it in the bin, then install the new sucker. If your using a MK 3 unit, you will see it's slightly different and you may have to alter slightly- you will see what I am on about when you compare the old to the new.
13- re-assemble the unit with the metal clips- they are easily pushed on with your fingers contrary to what I was told (I have tough fingers though). I also found it was best to re-assemble the upper and lower plastic parts onto the heater housing before jiggling the whole setup back into the location or you will regret it.
14- tioghten the 3 x 10mm nuts and the 13mm bolt first then go forth with re-assembly.

It's a very easy job and not as daunting as you might think. Worth it as the heat in this crap weather makes driving the old beast a pleasure.

I spent a good 2 hours cleaning every item out of the car including the carpets so now my car is 100% as good as it gets.

Any specific queries- email me on aaron@vw1500.com Good luck.

[rob64981]

Thanks for the info i will look into doing this little project.
Rob

[sports racer]

I've just spent hours trying to get mine out. The 3 bolts threw me as I could only find 2 and it still wouldn't come out so I've been looking for the 3rd. There's 2 holding the airconditioning plate on the firewall and I undid both of them just in case. Once I re-read the steps above and undid the metal clips it finally came out. Now that it's out I can confirm there are only 2 bolts on my heater box.

[ryana89]

Thank-you!
This will be very handy when I change mine.
Can I ask where your sourced the new heater-core from?
And how feasable is it to get the original MK2 heater core, or should I just not worry and put a MK3 core in instead?

BTW did you purchase the white auto MK2 that was for sale in Sydney a few weeks back?

Thanks

[benough]

I got my heater core from german auto parts.com

It's for a MK2 but it's the same tech as a the MK3 one so you don't need the bleeder valves etc.

I think it was $70?

[sports racer]

Now that I've got the new heater core in I need to fix a few things that don't work since I started yesterday. Somehow I've killed the headlights - can't get low beam and high beam only stays on as long as I hold the highbeam stalk. The thermo fan also comes on as soon as I turn on the ignition, even when it's zero degrees outside.

I have no idea what I've managed to upset but I need to have a good look at the wiring.

Anyone know where I can get a workshop manual cheap? Or at the least a wiring diagram.

Cheers

Paul

[NeuSpeedGTI]

Should be plenty of wiring information here.

A2Resource

Very useful site!!

Good luck!

[sports racer]

Thanks for that. You're right, very useful site.

[Notchback]

One thing to note- the MK 3 heater core I bought (I was told it would fit the MK 2) is slightly different to the original MK 2 unit.

Yes the MK 3 unit slides in and works, but the angle of the dangle for the hoses is slightly different and makes tighteneing up the hose clamps a real pain in the butt. Beggars can't be choosers it would appear.

Also, after exhausting my contacts in Australia, Europe, UK and the USA for a replacement hose from the cylinder head to the heater core & trans cooler, I went and sourced all the fittings and hoses localy to replace the original torn hose today.

As my car is an automatic (sigh), the original hose is extremely unobtainable, hence the new hoses and fittings.

This concludes (I hope) my coolant and heater issues for this car.

Enjoy your MK 2's chaps!