Coolant leaking into footwell

[kath]

Hello all, I am new here and am asking for help on what I should do for the best.

My main problem is: My footwell is filling with 1 litre of coolant every 10 miles, and it seems to be coming from the heater matrix. I found a brilliant thread on how to change the broken heater matrix on a VW, and would love to do the job myself but am worried the A6 would be very different, and I would get stuck. Has anyone here any hints or clues or warnings beyond not letting the car overheat?

Any advice would be very much appreciated

Kar

[Peter D]

If this is the passenger side then you about to say goodbye to your CCM unit under the floor, locks and interior lights stop working then the battery goes flat and the bill starts at £230 plus vat and £90 for recoding and key immobiliser recode. Put Plenum Chamber into the search window and read the horror stories. Regards Peter

[kath]

Thank you for your warnings Peter. I will do what I can to keep the electrics dry... My remote imobiliser doesn't work anyway - the car is a 1997 model and I have to put the key in the door for the central locking. If I go ahead to replace the heater matrix at which point do I need to disconnect the battery?

The way I see it, without merely redirecting the coolant and disabling the heater, the job has to be done. My sticking problem at the moment is getting the glove box open (since it jammed shut) so I can access the screws to remove it and gain access to the plumbing.

The passenger seat and side trim came off ok, and I am on my way to collect the matrix and clamps. Yarg...

[Peter D]

Disconnect the battery now before you do further damage and you loose the main cable harness. Peter

[kath]

Started on the job on 1997 AUDI A6 Friday midday.
Finished the job and went to the pub on Sunday evening.

HEATER MATRIX 1997 AUDI A6
THIS 7 HOUR £700 JOB TAKES NOVICE 3 DAYS
HERE ARE THE COMPLETE INSTRUCTIONS

NEW FITTINGS:
Had new heater matrix (small radiator with 2 pipes out for hose connection), also heat resistant silicon sealant, also 1 or 2 bottles of coolant.

TOOLS:
Metric socket set with extensions and ratchet, needing sizes 8, 10 and 13mm.
Set of six-pointed star type screw driver head attachments, needing sizes 10 and 25.
Very long cross-head screwdriver for 4 hidden screws deep in middle of matrix.
2 flat head screw drivers for popping off clips.
Containers and sticky labels for screws, bolts and clips.
These instructions and a notebook and pen and maybe a camera for clues as to how to reassemble.

MISSION
Replace very leaky heater matrix: so to do this:
Dismantle interior of car to access heating ducts and electrical connections so as to loose up the heating matrix housing behind the central consul control pannel.
Dismantle exterior of car below windscreen so I could pull the matrix housing out.
Dismantle the plastic housing with the air direction flaps and matrix, and electric air heater inside.

ORDER OF DISMANTLING
(NB: Make sure windows are closed and all doors are unlocked before removing battery so the rain cannot get in over the next day or so.)
(NB: Don’t force any fittings – if they won’t come off there will be another screw or clip that needs to be released by pinching or lifting with a flat screwdriver)

UNDER CAR
(NB: Never use an ordinary car jack because the car will kill you if it lands on you)
1. Drain the radiator by unscrewing the hose clip from the lowest fattest hose, wiggling off hose and taking off the blue cap on the top pressure bottle.
2. Collect the coolant in a container and pour it down the drain immediately – it kills dogs and maybe children if they drink it because it tastes sweet.

UNDER BONNET
1. Remove rain cover (plenum).
2. Remove battery (negative black then positive red)
3. Unclip golden metal strap over plastic housing
4. Remove windscreen wipers (pop off plastic caps, press on hinge to release sideways pressure, wiggle off the threaded posts)
5. Remove plastic cowelling using size 25 hexagon star bolt screwdriver and WD40 and tapping with hammer to shock loose, then windscreen lower seal panel by popping clips off with a screw driver (keep finger on these to stop them flying off and embedding themselves in your eye)
6. Remove aluminium wiper mechanism tubes with motor (unclip electric block) from car body.
7. Unclip 2 electric connectors on housing.
8. Remove hoses from housing.
9. Unclip white air flap mechanism (take a photo of how it goes),
10. Set the little wire cable keeper to one side.
11. Remove windscreen support things with 2 x 10mm bolts each.

IN CAR
(NB: The carpets are formed with masses of foam under them in the factory so they cannot be removed and will have to be washed in situ.)
1. Remove passenger seat (pinch the single plastic clip at the front, pop off the cover over the car door side runner and unbolt stopper, tip seat back and slide out of runners). First cover rear carpeted arch to avoid grease marks.
2. Could remove drivers seat too.
3. Unscrew gear knob and clip off gator with a flat screw driver.
4. At the back, undo side bolts on handbrake consul.
5. Undo bolt below handbrake.
6. Lift and unclip rear cigarette lighter electric block.
7. Lift off panel and see if there is another bolt to the handbrake trim.
8. 2 x bolts holding gear stick surround panel in.

PASSENGER SIDE GLOVE BOX
1. Pop off side panel with screwdriver.
2. under this undo 2 pinch clips (need 2 flat head screw drivers for these) and 2 bolts.
3. Fully open glove box and with head under: RHS (right hand side) 2 bolts, LHS 2 x six sided star bolt/screw, RHS 1 x six-sided star bolt/screw

DRIVERS SIDE SHELF
1 Just 4 short bolts and 1 long bolt (you could get your husband to do these so he feels useful – or he could make a cup of tea).

CENTRAL CONTROLS CONSUL
1. Put heater controls in upright position.
2. Draw a plan of push switches and pop off any 2 blank ones to the side, also 2 triangular ones at the bottom.
3. Remove ashtray.
4. Pull off knobs (can leave switches in place), undo the 2 revealed screws.
5. Pull off the panel under these.
6. Undo 2 x corner bolts from grey panel, and remove this panel.
7. Pull off the air director grills.
8. Undo 2 x bolts on black control panel. (maybe 2 more also)
9. Coax off panel to expose electrics.
10. Be amazed at the amount of water around the electrics.

DUCTING
1. Pull off the wet lips where the vents were.
2. Head under passenger side and pull off passenger side vent tube (may have a tie on it)
3. Pull off corner shaped short piece of duct.
4. By handbrake lift up rear seat duct and disconnect from behind front consul electrics
5. More ducting on drivers side – corner piece and long piece.
PASSENGER FOOTWELL
1. remove wire from aluminium keeper.
2. Awquard black bolt on footwell ducting to side vent.
3. Separate white part of control consul from black box part of control consul.
4. Unclip large black electric connector.
5. Unclip brown, red and black tension cables from white box, and label where they go so you can put them back again.
6. Remove metal 2-piece support (4 bolts)

DRIVERS FOOTWELL
1. Really difficult screw to matrix housing needing 8mm socket and torch.

UNDER BONNET
1. Use large flat screwdriver to release the matrix housing from the really sticky foam it is mounted on.
2. Get someone to bring you a broom handle.
3. Lever up the matrix housing from under the bonnet, and work out what it is still connected to on the inside (3 electric connections – Red 6-connector, Grean and white wires to purple round connector, Brown Live to airbag sensor).
4. Write down that the big brown live wire is connected to the underside of the airbag sensor. Hold on to that screw and stick a label on it.
5. Get someone to guide out all the dangly bits as you Lift The Thing Out.
(If it has been fully disconnected it should come out fairly easily).

IN THE KITCHEN

1. Use a big flat screwdriver to chisel out all the rubbery silicone sealant.
2. Undo all the screws that hold the 2 halves together.
3. Prise off the clips with a screwdriver – keeping one finger on them so they don’t fly off and get embedded in the family pet.
4. Take the 6 screws out at the top – you can then remove the thing that blocks the entrance.
5. Take out the screws from the fan and flap / big white thing.
6. On LHS take the clips of the white pegs (posts of inside flaps)
7. Also the double clip and foam washer just under the matrix pipes.
8. There are about 4 screws down holes, deep in the middle that hold the 2 halves together, so you will need the really long crosshead screw driver.
9. As you pull the halves apart record the angles of all the inside air flaps.

REPLACE HEATER MATRIX
REASSEMBLE IN REVERSE ORDER
REPLACE LOWER HOSE CLIP AND FILL RADIATOR WITH ANTIFREEZE/COOLANT AND WATER
CONNECT BATTERY RED POSITIVE CONNECTOR FIRST, THEN BLACK NEGATIVE
TEST FOR BURNING ELECTRICS AND CORRECT COOLANT CIRCULATION WITH NO AIR LOCKS / LEAKS
CHECK ELECTRICS AND CONTROL BUTTONS
GO TO THE PUB

[Peter D]

Well done that man. Regards Peter

[shabazmo]

Kath, Excellent description and thanks for the procedures. I had a similar problem but it was the aircon drain plug that was sticking which caused the passenger footwell to flood with condensate water. Hope you fixed the problem.

[paul b]

How's about one of the moderators make this a sticky... or add it to the 'How To' section?

Paul

[gilson]

Well done that man. Regards Peter

Kath's a funny man's name... but all the same, exceptional job. Much respect.