06-12-2012, 01:38 AM
After driving around for over a year with no heat in my pug 405 enough was enough so i finally bit the bullet and decided to do the dreaded heater matrix change.
The 405 is pretty much identical to the 306 in the layout of the heating system, so to start with I set about it as you should, removing all the center console and bolts holding the dash in place.....
![[Image: IMAG0488.jpg]](http://i1310.photobucket.com/albums/s649/ozonehostile/IMAG0488.jpg)
This took bloody ages and it was getting cold and I was getting pretty pissed off with undoing tiny little screws in near enough inaccessible places, so a quick re-evaluation of the process later and this happened:
basically all you need to do is remove the glove box to expose the heater blower motor like so:
![[Image: IMAG0484.jpg]](http://i1310.photobucket.com/albums/s649/ozonehostile/IMAG0484.jpg)
remove the motor to make some more space to work under the dash, then drill out all the pop rivets holding the glove box surround in so that it exposes the metal bar that runs under the dash.
once you get to this stage, its out with the angle grinder, cut the lower dash rail in half as close to the center console as you can then bend it down out of your way.
you will now be able to see the end of the heater matrix and the two metal pipes going in and out of it behind where the ashtray goes. the corner of the center console is obstructing the rest of the matrix so use your trusty grinder to cut away the corner, just enough so that you can easily get to the matrix
the two pipes on the matrix are held in by a flange with a screw that is totally inaccessible, so to gain access drill a hole through the dash like this
![[Image: IMAG04921.jpg]](http://i1310.photobucket.com/albums/s649/ozonehostile/IMAG04921.jpg)
using a long screwdriver you can now undo the flange, but have the drip tray at the ready because as soon as you loosen the pipes its going to start leaking, also worth mentioning at this point that you should remove the radiator cap before you do this to relieve any pressure as you don't want hot water pissing out everywhere.
with the flange undone you should now be able to slide out the old matrix no problem
![[Image: IMAG0489.jpg]](http://i1310.photobucket.com/albums/s649/ozonehostile/IMAG0489.jpg)
now its a case of simply sliding in your nice shiny new one in and reconnecting the hoses to the flange (you will need two O rings to go on the ends of the heater pipes otherwise it will leak)
Top up the radiator, start your engine, let it warm up for a bit while bleeding the system of any air, you should now have lovely hot air blasting out of the dash again.
this method is a million times quicker than doing it "properly", you just need to be prepared to sacrifice a tiny piece of dashboard and having a hole drilled through, i plan to fill it in with some black silicone sealant, the dash rail can be bent back up into position and you will need some new pop rivets to re attach the glovebox surround and subsequently the glovebox itself.
Hope my bodgetastic method for a quick heater matrix change proves useful haha
The 405 is pretty much identical to the 306 in the layout of the heating system, so to start with I set about it as you should, removing all the center console and bolts holding the dash in place.....
This took bloody ages and it was getting cold and I was getting pretty pissed off with undoing tiny little screws in near enough inaccessible places, so a quick re-evaluation of the process later and this happened:
basically all you need to do is remove the glove box to expose the heater blower motor like so:
remove the motor to make some more space to work under the dash, then drill out all the pop rivets holding the glove box surround in so that it exposes the metal bar that runs under the dash.
once you get to this stage, its out with the angle grinder, cut the lower dash rail in half as close to the center console as you can then bend it down out of your way.
you will now be able to see the end of the heater matrix and the two metal pipes going in and out of it behind where the ashtray goes. the corner of the center console is obstructing the rest of the matrix so use your trusty grinder to cut away the corner, just enough so that you can easily get to the matrix
the two pipes on the matrix are held in by a flange with a screw that is totally inaccessible, so to gain access drill a hole through the dash like this
using a long screwdriver you can now undo the flange, but have the drip tray at the ready because as soon as you loosen the pipes its going to start leaking, also worth mentioning at this point that you should remove the radiator cap before you do this to relieve any pressure as you don't want hot water pissing out everywhere.
with the flange undone you should now be able to slide out the old matrix no problem
now its a case of simply sliding in your nice shiny new one in and reconnecting the hoses to the flange (you will need two O rings to go on the ends of the heater pipes otherwise it will leak)
Top up the radiator, start your engine, let it warm up for a bit while bleeding the system of any air, you should now have lovely hot air blasting out of the dash again.
this method is a million times quicker than doing it "properly", you just need to be prepared to sacrifice a tiny piece of dashboard and having a hole drilled through, i plan to fill it in with some black silicone sealant, the dash rail can be bent back up into position and you will need some new pop rivets to re attach the glovebox surround and subsequently the glovebox itself.
Hope my bodgetastic method for a quick heater matrix change proves useful haha
Current stable
'09 Mercedes E320cdi wagon
'99 306 gti6
'09 Mercedes E320cdi wagon
'99 306 gti6
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