Heater blowing cold not hot - matrix cleanse and air flaps foam refurb guide

The MK2 would only blow luke warm air when hot selected. And it would blow through front vents and windscreen when only windscreen selected.

I tried every suggestion on here and other forums;
recently had a new thermostat and water pump,
all engine pipes HOT including both the matrix feed and return pipes,
Bypass valves removed,
Coolant system flushed with numerous cleaning products and then bled properly.
Checked arrows on the flap placement and all aligned.

Decided to get the tools out and strip the interior as I expected a clogged heater matrix.
It turned out to be knackered direction flaps inside the whole heat exchange unit as mentioned in many posts in here.

Here are some photos to help chaps that are taking on this task as it's a ball-ache going in blind. I didn't know what to expect myself so I thought that I would throw a few pictures together for anyone considering repairing theirs.
but here's the thread I used to start with

flaps set to cold


flaps set to HOT


And the air placement (window or feet etc) set to window; which explains why air was coming through both the window and the front vents when ONLY window was selected.


And the air placement set to front main (pax and driver); and it also came out of the other vents whilst set to window.


Use the other guide linked above and it will explain how to begin to get the exchange unit out.
I had three bolts in the engine bay: one under the blower unit and two about 40cms apart vertically in the center of the bulkhead behind the exhaust manifold. The bottom one was a ball-ache to remove as it had rusted a bit. These are 10mm nuts.

Follow the guide to remove the front vents etc and remove the blower, then the chamber from the blower to the exchange unit (this is with clips and undo the big black plastic nut above the actual blower).
Remove all three cables (2 underneath and one on the right hand side (this controls whether to send up to the windows)). Be careful doing this as I've broken them before.
Remove the other chamber to the front vents opposite side of the blower.
Undo the heater matrix feed and return valves.

I then used a hammer to hit the bolts in the engine bay side as pulling the unit from the interior just wasn't enough.
Pull hard and down but carefully and it will pull from the top vent outlet.



Once home and warm I pulled the matrix out of its holding and it was full of bugs and spiders LOTS OF BUGS AND SPIDERS


here's looking down into the matrix housing. The bits are mainly foam, BUGS AND SPIDERS; I DID NOT LIKE THIS.


Here's a better look at the deteriorated hotcold flap (it's in its half way position, the left of it goes through the heater matrix)

This is both flaps. the one on the left is the HOTCOLD flap and the right is the top, bottom vents and window flap




I wasn't sure how I would be able to get the flaps out but once you're at this stage it's really simple.
On the above picture you can see that the unit is made of two halves one on top and one below.
There are clips holding them together which can be undone with a knife.
Now, if you only want to do the flap repair you may be able to undo this bottom half whilst it is all still connected up in the car but I think that this would be really hard as there are quite a few clips and they're all the way around the unit.


I undid a few of the clips either side of the front facing flap and gently pried the two halves apart but didn't fully separate them.


the above picture has the flaps removed. The next picture is how to get them out, it's easy. The top of the flaps are on the right hand side.
take this side out first and they will have plastic bungs on the top and the bottoms pull out directly from the cogs that the cable move.

the bottoms slot into the cogs right at the bottom of the unit


once out you can bin the knackered foam insulation, clean them up and fit whatever you see fit for the job.



The old foam is about 3mm thick and quite dense and it's on both sides.

I went to the fabric shop with a 'sample' of the foam and the lady suggested heatproof vinyl table protector (which she happened to stock haha) it's vinyl one side and dense fabric on the reverse. It seems bang on: heat resistant, same thickness and you can stick the vinyl to the metal flaps and the thick fabric will act as a seal.

I'll post some more pictures up when I fit this.


Whilst the matrix was out I decided to test it with this rig;


It was full of much and rust particles but after running very hot water through it for a while it just got clearer and clearer and all the pipes began to get to the same temp and hot. I was giving it a good shake in all directions now and again and used washing powder as suggested in other threads and it really worked.
I've doubt that the flow is restricted in any way with it now.



However I might stick a MK3 matrix in there for safety

 

this is a brilliant write up mate thankyou

 

Thanks for taking the time to write that up! Looks pretty straight forward now. I expect mine could do with a spruce up!

I bet your missus is happy with you washing that out in the sink in the penultimate picture! lol

 

Thanks for taking the time to write that up! Looks pretty straight forward now. I expect mine could do with a spruce up!

I bet your missus is happy with you washing that out in the sink in the penultimate picture! lol

 

Excellent guide - I was looking at a MK2 airbox the other day thinking about how to do a similar refurbishment.

 

No problem guys.
I wasn't sure what to expect with it and I honestly thought it would be such a mess that I'd go all summer with it all out!

refitting is probably gonna be a balls effort but we'll see.

she said; "I want to do the washing up" to which i replied; "you can after; I need (WANT) to do this!"

ha

 

Couldnt agrree more. Great guide, will be using this very soon.

Looking forward to seeing this vinyl fabric stuff, any chance of a close up pic, when you get the stuff, so I can try match it.

 

I'm doing it now and have some pics of it all split open and close up to show it fits and works.

 

What a hero!

PS. It's really really hard not to stare at your avatar! lol

 

Yeyah! I love that cat.


I bought the stuff from the fabric shop and it's a little thicker than the original stuff but it's fine because the fabric side is compressible. It's about 5mm, I wouldn't get anything thicker really.


Here's all the stuff I used.
The fabric cost me 1 and the tape is clear double sided super tacky stuff that bonds to vinyl and metal and was 2. I used about half of that fabric.



I roughly cut out the fabric to size, make it a little bigger around the edges, when you get it all opened up it's easy to see where you should leave it longer to get good seals everywhere. And I covered one side with tape, stuck the fabric and did the other side. I then fitted it up to see where it needed trimming. I needed trimming mostly at the top and bottom of the pivoting points.


both sides of the fabric fitted



And fitted into the box;




Top view;


Top view split in half, here you can see where the third flap is, this sends air to either window or feet;


this third flap has a different foam on it and it collapses when you press it down (just old), mine's deteriorated but isn't falling to bits and still makes a seal so I'm not bothering changing it but check yours.


Here's the 2nd one done;





You may want to clean these out and re lube them to keep the cogs moving and less strain on the cables; Note their orientation before removal.


Hot/cold flap in mid position;




Front flap;


On that last picture there are two pegs that stop the front flap fully closing and a gap of about 5mm remains, I'm unsure why this is. Maybe it's to keep some airflow and keep it clear if the driver decides to always keep it going up to the windows. Unsure. I put a strip of fabric up along the side to bridge the gap a bit. If I want it on my windows to defrost them better then I want it all going up there.

Let me know if you need any info.

I'll post back once it's all back in, which I am not looking forward to.

 

That looks absolutely spot on! You've convinced me to do it now...I'm off to find some of that material! Well not right now lol

Thanks for taking the time to document this for us. Much appreciated. I reckon this worth sticking in FAQ's

Cheers,
Bruce.

 

Again, absolutely brilliant. I'll definitely follow this when putting the air box back into the G60.

 

Top man. This is a perfect weekend jobby.

 

No probs.
It's a nice little project that isn't too difficult on your own and offers great (hot) returns haha

 

Brilliant...........just brilliant, what is the correct name of the fabric so i know what im asking for

 

It's heat resistant table protector.

 

I'm not sure if mine even needs doing, but I'm bookmarking this page for future reference - great guide!

 

Great thread! I have bits of foam flying at my face through the vents, so must be that plus the heaters are abit pants

http://www.ebay.co.uk/itm/Table-Pro...pt=UK_HG_Crockery_RL&var=&hash=item1c0e482d32

Looks like the same stuff.

 

Cheers guys.
Yeah that looks like the stuff.
See if you can get to a fabric store or fent shop etc. You'll only need about an A4 sheet or perhaps maybe a bit more.

 

this defo needs to be a sticky! i will be doing this on my mk2, but im gonna wait till we get a our few days of summer!
but bring on next winter i will no longer be cold!