Technical HEATER Matrix unit removal

[richit]

Hi, has anyone suffered a coolant leak inside the car from the bottom of the heater unit? I've had my 2002 Barch for 18 months and it's always leaked a little when the heater control was on anything but cold. Yesterday the little leak turned into a torrent. There was more than a litre of coolant in the driver's footwell. This morning I attempted to remove the unit to see what's going on, but it's a nightmare. I can't see how to take it out. I have the centre consul out. It still looks very happy to stay where it is.

I've decided to bypass the matrix for now by re-routing the water pipes under the bonnet, as it's very hot here at the moment so I don't need heaters for a while, but I do want to use the car.

Any suggestions? THANKS!

 

[Ilkka]

Heater matrix leaks are not uncommon in barchettas, I've replaced mine too.
You need to remove the whole console to access the heater and the matrix, so you need to remove the instrument cluster, center console and steering wheel too. It's simple disassemble/reassemble but takes some 4+2 hours or so the first time you do it.
The are some rivets you need to drill out, and some bolts inside the round air vents that can be hard to find if you don't know where to look, but otherwise pretty straightforward. See the service manual for details, and I remember using a DIY guide from this or another forum, but can't see to find it.
Remember to disconnect the battery well before taking off the airbag, and to mark the steering wheel position before taking it off.

 

[richit]

Hi Ilkka, thanks so much. I took the centre console out but then lost my confidence.. It will be a 'nice' winter job. What was the leak on yours? Did you have to replace anything or just repair? Thankfully, there's no shortage of spares here. Please, let me know if you do find something in print related to it. I'll keep searching. Thanks again..!

 

[Ilkka]

There's only one wearing component inside the heater and that's the heater core. It's not expensive so just replace it with a new one, it's not even repairable with home tools. I don't think there's more than one type available, this looks like it:
http://m.ebay.de/itm/WARMETAUSCHER-...176-BJ-09-93-06-2000-/371113892778?nav=SEARCH
You have to drain the coolant obviously and then disconnect the hoses from the core, located I'm the engine bay at this point. Once you get the heater off, the core just slides out. Clean the heater body well before inserting the new core.
And remember to check that all knobs turn and function as they should as you reassemble the heater, it's so much easier to fix possible faults when the dash is still off.

 

[richit]

Thanks Ilkka! You've given me confidence to do it. We're planning a trip around Italy in September so it can wait until after that. I'll update when it's done. Thanks again.

 

[s130]

Well I don't wan't to be here but now I appear to have a small leak from somewhere in the matrix / assembly.

I had noticed a while ago some fine dribble of water stain marks by the throttle pedal but after cleaning nothing ever happened again.

After the car standing for 4 weeks whilst on holiday we found around 0.5cc (or less) of fluid in the groove of the foot-well mat.

I've just looked at the ePER parts pictures and the official workshop manual and it would appear that there are NO water flow/other control valves. i.e. the water goes into and out of the matrix with not other components involved? Can someone plase confirm?

My opinion is we have pin prick leak that is only leaking during relaxation. i.e. heat relaxation as the matrix cools. At cold there are no leaks. When hot there a not leaks.

This would normally be against my better judgement but I'm thinking a dose of K-Leak, Wynns / other reputable sealant is now my first port of call all things considered.

For very minor pin-prick leaks reports seem to suggest these leak sealant *modern* products provide an almost lifetime repair with no side effects and coolant system clogging that the old mustard powdered solutions produced.

From my point of view I need to nip this in the bud now by either trying the sealant approach (note I'm talking about 0.5cc or less over several months) or grounding the "B" for quite some time and also potentially risking damage to plastic panels, panel fixings, cable harness damage/interference etc.

Opinions would be appreciated. More importantly reports of people with pin prick leaks having used "sealants" and their eventual results/performance.

 

[Ilkka]

0.5cc is very little, so it might be also condense water and not coolant at all.
If you are sure it's coolant then a sealant might work for a while, though they usually are a temporary fix - mine cured with a black rubbery type sealant for a few moths, and then started slowly leaking again. There's no harm in trying, just follow the instructions about the dosage, and see if it helps or not.
If you eventually need to replace the matrix, replace the coolant with a fresh one.

EDIT: my heater had no valves, just a flap to adjust the amount of air flowing though the heater matrix, and direct hoses to the matrix.

 

[s130]

Thanks Ilkka

Yes the water was coolant/antifreeze, long life red and sweet on the tongue

I've now gone down the Holts Radweld Plus route. If this fails then I'll rip the car apart removing the dashboard and hopefully I'll end up with NO damaged facia, trim etc.

After 42+ years of working on cars (mainly Fiats/ also others) trim removal and replacement has to be my biggest concern. For any Fiat car over 8 to 10 years old vehicle trim / mouldings /etc are more than likely "out of production" and "no longer supplied/available".

Thanks also for the confirmation that the heater system/matrix has no water control valves (like in the Tipo & Tempra models).

Nick

 

[richit]

Hi S130, mine started with a very small leak. It just dribbled down the side of the tunnel. Every time I check the fluid level it was a very small amount gone. There was always a smell of coolant when the heater was on hot. I had the car 18 months then it just suddenly got much worse so has to be done.

Getting the panels out wasn't too difficult. I got so far but then couldn't see how the unit disconnected from the car so decided to put it back for now until I have more time and cooler weather. I think getting the panels off is the 'easy' part. Once you see it under the dash then you know you are in for a lot of pain.. It looks a bit of a nightmare.

 

[s130]

Well I would like to think the Radweld fix is long lasting but any time that it buys will be a bonus as the other car, my Croma 2005 needs the alternator changing an that too is a nasty little job buy all counts.

I often think cars speak to each other and collude together behind the owners back just to ensure they get to get their feet up together

 

[Russo]

I've replaced radiator. I spent more than 12 hours. So many things which are not showed in manual! Good luck!

 

[richit]

12 hours!! Oh no! Mine is still wrapped up in the garage ready for me to start on it. I'm not scared but I am just a little bit terrified.. Any tips?

 

[s130]

Thankfully for us the Radweld is still holding strong.

You could of course go all electric. 140A+ alternator plus 1KW heater plus/optional mains inverter. Assuming nothing goes up in smoke, 1KW @ 12V = 83A. So 140A alternator will have nearly 60A spare capacity.

Downside is that the MPG will increase during winter but could also fractionally decrease during summer due to lower water pumping costs.

 

[richit]

Hi Ilkka - as you've done this task before, can you help? I just spent a couple of hours taking out the centre consul etc to get the matrix - do I have to remove the front part of the dash and passenger airbag before I can get the heater unit out? Thanks!! I don't want to take out more than I have to but so far so good.

 

[richit]

A little update and some suggestions of how to get the heater unit out:

To get the heater unit out you have to remove the front part of the dashboard and to do this you have to remove pretty much everything that’s in front of it - centre console, steering wheel, and all the covers around the column, instrument cluster, etc. I also dropped the steering column - just 4 nuts - then held the column up with a piece of wire.

The passenger airbag needs to come out too. I broke the little white clips that hold the bottom of the front panel in place… they’re suck fast in the dash. I think some strong double-sided adhesive tape will be ok, or some strong glue on the points that broke. It’s not a big issue. The fuse and relay panel below the airbag needs to come out too. You have to take out some silver screws and drill out 4 rivets. It’s very easy. Pull all the cables out of the way. (For the heater unit there are 2 plugs on the left near the pedals - one grey, one white - and one behind that you remove once you get it free. You don’t have to unplug all the others).

You also need to unplug everything going into the main fuse box and a few other plugs. Just look and see what might prevent the dash getting out. Pull all the plugs through the hole in the dash.

The two extreme vents, nearest the doors, have to come out too. Just pull them out then pop the clips to pull out the sleeve tubes. You have to remove a hex bolt that secures the dash on each side behind the vents. No need to take the central ones out. I also removed the windscreen plastic trims on both sides to give the dash more room to come out.

I labelled each plug so I have a better idea of where they go back. The problem is not plugging a wrong plug into the wrong socket but how to route the cables.

Under the bonnet you have to remove the two water pipes and the two silver aircon pipes (you need to get the AC professionally drained of gas first). There are also two bolts - one behind the power steering reservoir (you have to unbolt the reservoir and pull it out the way), the other is near the water pipes going into the car.

If you don’t have a special tool for removing the Fiat pipe clips I found this very effective - a piece of wood about 30cm long and 3cm x 3cm, hold it above the pipe (or as close as you can) then with a small crowbar resting on the wood and the sharp end behind the clip push with a little pressure and they pop off easily.

There are a few obviously bolts to remove inside that hold the unit in place, and the vents that supply the windscreen. At this point it still didn’t want to come out. After 20 minutes of wiggling and pulling I realised it had become attached to the soundproofing behind. I pulled it out enough to get my hand down the back then gently separated the matting from the unit.

The heater radiator is very easy to change once the unit is out - two small screws. The old rad looked fine but it seems it was leaking out of a rubber seal on one corner. I bought a replacement from Germany through Ebay for about €35.

Now I have to put it back together. First, I’m going to add some soundproofing and I need to replace the ‘O’ rings on the aircon pipes. I think it’s a good idea to clean all the air vents and tubes too as they’re full of dust, and that can’t be too healthy. We’ve got amazing weather here in north Italy at the moment - not good for the skiers but can’t wait to take the Barch for a spin!

Don’t hesitate to ask if you need help taking on this task!

 

[richit]

 

[Stum]

Great job there, well done.

 

[richit]

Thanks Stum! I'll be even happier when I get it all back together and I know the car still works

 

[s130]

Thanks richit

Your strip down information and pictures are extremely informative.

Thus far, and thankfully, the Holts Radweld Plus application is holding firm on our "B".

I don't normally opt for a cheap solutions to problems but sometimes a gamble is worth the option. As with all options/gambles then safety comes first (eg. massive hot fluid release - not a high risk is in this case) and you have to be prepared to re-visit the issue again and spend even more time and money on a proper fix.

Wish you and your "B" all the best!

 

[gar074]

There's no way I'd be brave enough to tackle a job like that - well done so far, and best of luck in putting it all back together again!