2.1 Td Heater Matrix Replacement.

[bobtee]

Hi everyone .
I just had to replace my heater matrix due to coolant leakage into the car and severe misting of the windscreen when trying to demist!!
It is possible to change the unit without removing the steering column .
I dont think you could remove an existing good one without removing the steering column without damaging the fragile alloy fins.
You need to remove the lower cover under the steering column and the plastic lump that holds the diagnostic socket and dash light dimmer .
Remove the offside central console trim, 2 screws in front heater vent,then pull out, 1 screw in rear vent ( grill) then pull out, also nut at rear end of trim (hidden under fabric) there is a + cut in the material to allow access, screws are torx type,nut was 10mm socket size i think.
you can then see one side of the matrix and the two alloy water pipes going into the matrix where they join the plastic bends into the matrix.
You must drain the cooling system at the radiator or some convenient low spot.
There is one self tapping screw in the plastic body holding in the matrix, cross point i think, and one torx set screw securing the pipe clamp bracket (holds the alloy pipes into the matrix pipes ),remove the screw and you can slide the bracket along the alloy pipes out of the way.
You will need a container to catch leaking fluid from the pipe joint.
it also runs down the plastic duct which i forgot to tell you to take off so be warned.
An ice cream tub works ok.
The fluid tends to dribble out for a while and you cannot control its direction very well so rags as well?
I then used a small electric drill with a small drillbit and drilled a series of holes to enable a fine hacksaw blade to cut out the triangular rear side of the plastic body.
This is the same as is reccomended in Haynes manual.
you can use the drill as a router to cut a slot Use some mole grips to wriggle back the alloy tubes until they are clear of the plastic bends. With that section removed you should be able to wriggle out the old matrix BUT it will damage the fins.
When i reached this stage i was afriad of causing some damage to the plastic housing so i sawed off the plastic slat that is inside the plastic body of the heater casing its about 1 inch wide and sticks out at right anle to the casing half way up the back and runs horizontally .
The old unit now comes out easily.
Pull straight out towards steering column and down towards yourself.
Clean out dead rats etc .
The new unit from gsf came with new o rings and foam seal.
there is a clip on plastic end cover on the new matrix it will not fit in the casing if you leave this on.
i did not use the foam seal on mine as it rucked up while sliding the matrix in.
Fit the new o rings.
There is a blind hole in the plastic section that was sawn out you can drill a hole there and use a new self tap screw to fix this piece in place and glue or tape up the slot left from sawing i used plastic padding .
refit pipes into plastic bends and secure with screw clamp part.
Fill up system and check for leaks next would be wise i think.
Hope this helps someone out there .
Best regards Bob.

[noz]

Hi Bob,

Thanks for your detailed description. Did you manage to take any photos whilst you did it?

Replacing the matrix boils down to two distinct methods. All others seem to be a variation on a theme.

1. Cutting a triangular section out of the plastic matrix housing to allow the matrix to be withdrawn. The triangular section cut out is then replaced and patched up with some tape or other method. As you just described.

2. Release the steering column and allow it to swing out of the way thus allowing the matrix to come straight out. Replacement is the reverse of removal.

Having done 3 matrices now I have to say I would still recommend the steering column method mainly because there's no damage to repair once the matrix is replaced. You shouldn't let the phrase "steering column removal" scare you. The column support bracket is held on by 4 x 13mm nuts on captured studs. They are extremely accessible. The only other part to disassemble is where the steering column actually connects to the part which goes through the floor. However, this is held on by one 13mm bolt. Once the bolt is withdrawn the two halves of the column part very easily. It is a round shaft with a flat so there's no problem identifying the correct alignment at reassembly. Once the 4 nuts and the one bolt are removed the column pivots on the upper part and the lower half comes completely out of the way to allow the matrix to be withdrawn.

Either way, getting rid of the indoor sauna is a definite bonus.

Cheers

noz

[bobtee]

Sorry everyone no photos .
Allways willing to help if anyone gets stuck ,just get in touch.
That method of just moving the column over sounds brilliant noz wish i had thought of that.
Best wishes Bob