After having to scrape ice off the inside of the windows, I recently discovered soaking wet carpets in the front footwells of my diesel Panda (no air-con). The source of the leak would seem to be the joint of the heater matrix to the flow/return pipes at the passenger (UK) side of the matrix - see attached JPG for clarification of the suspected location of the leak. There is a very small leak which I have been unable to stop, but the cumulative effect has meant very wet carpets with the escaped water being the same colour as the coolant; pink. The plastic to plastic joint is held together by a single central bolt, which I have been able to tighten up, but this has made no difference. I cannot find any information to show if there is a gasket or a rubber seal in there. I have considered taping the joint up with central heating repair tape, but am not sure whether that would simply allow pressure to build up and cause a bigger problem later.

My question is, before I try to pull things apart to no great benefit, has anyone got any idea what would be the best way forward to plug this leak, or might there be a problem with the matrix that I can't really see? If so, how would I know the matrix was the culprit?

Is there anyone here that has replaced their heater matrix and can advise on this issue, or is there anyone who might know how this joint is supposed to be sealed?

MikeySkiBoy said:

Is there anyone here that has replaced their heater matrix and can advise on this issue, or is there anyone who might know how this joint is supposed to be sealed?

Click to expand...

I haven't replaced it, but on reading FIAT's workshop documentation, it would appear this job is a complete horror ! It seems you need to remove pretty much everything inside the front of the car, including the steering wheel, airbags, most of the dashboard and one of the doors .

Perhaps someone who's actually done this job can come along and post their story?

Oh dear, oh dear, oh dear!!!! That really doesn't look good, but thanks for the heads up and for your concern. I was getting very lonely here.

I've already got the bottom of the dash off and can get reasonable access to the side of the matrix and the bolt that holds the join together. In my naivety, I think I'm going to have a go at draining the old girl off. Once that's done I will see if I can split the join, and perhaps have a look at the matrix, if it slides out as it looks like it does. Perhaps some form of sealant in the join might just do the trick, or a new matrix might be required.

Whatever happens I will post what occurs back here for the benefit of all mankind; especially those that might have a leaking heater matrix joint in their Panda.

MikeySkiBoy said:

Oh dear, oh dear, oh dear!!!! That really doesn't look good, but thanks for the heads up and for your concern. I was getting very lonely here.

I've already got the bottom of the dash off and can get reasonable access to the side of the matrix and the bolt that holds the join together. In my naivety, I think I'm going to have a go at draining the old girl off. Once that's done I will see if I can split the join, and perhaps have a look at the matrix, if it slides out as it looks like it does. Perhaps some form of sealant in the join might just do the trick, or a new matrix might be required.

Whatever happens I will post what occurs back here for the benefit of all mankind; especially those that might have a leaking heater matrix joint in their Panda.

Click to expand...

hi , jusdging by the lack of response - I think you are in uncharted teriitory there..!!,

I had a leak on my Mk 2 panda matrix - engine bay area..luckily..!!,

it was actually the plastic fitting on the end had a crack in it,
pretty sure I sealed the replacement with "BOSS-White" = plumbers mait type stuff - VERY tacky , doesn't go too hard,

have fun..,
Charlie

Thanks Charlie.

At the weekend, I did try to split the joint apart slightly, to see if there was any form of seal present. If there was a gap then available, I was going to squirt in some Fernox LS-X leak fix, which sounds very similar to your BOSS-White stuff and is supposed to be used in central heating pipework, so should easily be up to the job. Unfortunately, coolant started running out immediately, so I had to tighten everything up again.

A crack in the plastic flange bit was my very first thought, once the quick tighten up didn't seem to help. It's simply not possible to see, so I won't really know until I can split it apart.

I've got some Prestone Extended Life Antfreeze from Costco, which is supposed to be suitable for any engine and, weather permitting, I might drain her and have a go at it this weekend. I'll update this thread once I know a bit more and hope that it might help some other Panda parent whose baby has started wetting itself.

I'm not convinced Fernox LS-X is a good idea - it smells and behaves like silicone bathroom sealant.

If you want to bodge it (IE a cheap fix repair without pulling everything to bits) try some radweld*.

* other makes of gunge are available.

I've just read your note John, but it is a bit too late as I've already been, gone, and done it! Thanks for your concern.

The Fernox LS-X is indeed a bit like a clear silicone sealant when it comes out of the tube. I do not think it is supposed to set quite as hard and dry as a bathroom sealant, so joints can be pulled apart again. It is suitable for use with plastics and is supposed to be used in central heating systems which would probably mean coping with higher temperatures and pressures than my Panda cooling system can muster. Hopefully I have not made a boo-boo and it will do the trick, but I will not know until I leave it for a while now.

I did have an earlier look at going down the gunge route, but after much online research I am really not convinced that would have been a permanent fix and could not find a guarantee that it would not cause other issues. As I have no intention of selling my Panda, I decided to minimise future issues and to try and plug the leak by a more direct and, hopefully, permanent method.

Anyway, I drained her out yesterday, after a very big fight with the "quick release" radiator connection, and was able to split the heater matrix joint apart. Similar to NASA's Space Shuttle booster rockets, the flow and return pipes have a rubber "O" ring that goes over the male parts of the joint, and then the whole lot ends up inside the female part of the joint at the side of the heater matrix. I couldn't see any cracks, so smeared some of the Fernox LS-X at the base of the pipe stubs, then pushed the "O" rings on as far as they would go and then smeared a bit more LS-X over the top of the ring, completely encasing the "O" ring in LS-X. I then remade the joint and tightened it up, which resulted in some excess LS-X coming out the sides of the joint. That was all smeared over the joint and hopefully it is now completely water tight from the very outside edge of the joint, to the top of the flow and return pipes as they bed into the matrix housing. I left it for a few hours to cure for a bit before refilling the cooling system with water and left it to run for a while. I then flushed it out again and refilled with a 50-50 mix of Prestone Extended Life Antifreeze/Coolant, which is suitable for use in any engine, apparently. If I do still have a leak, at least it will be a nice lime green colour, instead of pink.

So far so good, but it is very early days and I won't really know until later in the week, to see if there has definitely been an improvement, and probably many months before seeing how permanent the fix might be! Whatever happens, I'll tryto make sure that I update this thread so that anyone else with a small leak at this joint might be able to sort it quickly.

it reads like you've made a "proper job" of it.

I've used gunge in the past on a "wet liner" engine which was leaking a bit at the outside edge of the cylinder head, just as it came out of warranty. I had the car for another couple of years, and the next owner had years of trouble free use.
But, as always, your mileage my vary.

Regarding antifreeze, ISTR that the pink stuff commonly used these days is "OAT" long life stuff, and mixing it with other technology antifreeze is a VERY BAD THING to do.

googling will provide enough to worry you about it turning to jelly, but I'd imagine you'll be OK with the complete draining and flushing you've done.

Antifreeze is supposed to find ANY leak path, so if it's still good after a week or so , youre probably fine - maybe wrap some kitchen towel around it / just below it.., you'll soon see if there is any new leaking,

Charlie

Hi John & Charlie.

So far............................ so good.

I've not put any panels back yet, but there hasn't been a sign of any unwanted moisture inside my Panda. I've had the area covered with white kitchen roll and, previously, it wouldn't have lasted a day before it was pretty obvious there was a leak.

However, I am still a bit wary and have not counted any chickens, quite yet. I'm going to leave it for a wee while yet and will report back in a week or two.

As far as the antifreeze goes, the marketing info states that "Prestone Extended Life Antifreeze Coolant is compatible with ANY antifreeze coolant regardless of color for use in ALL makes and models of cars and light duty trucks, petrol or diesel on the road today". Hopefully that is indeed the case and my coolant doesn't turn to syrup. I'll keep an eye on that as well.

Thanks for your ongoing concern.

Mike

Good news folks....... It looks like the procedure specified above has done the trick, and no coolant is now coming from the heater matrix joint and finding its way under the carpet and pooling in the footwells; particularly the passenger one. The carpet and the underlay, which acts as a very absorbent sponge, is almost completely dry now and rubber mats may be going back shortly.

The bad news is that I still seem to have to top up the coolant, but it is only a small amount now and I've only had to do it a couple of times since March. It may that I hadn't got all of the air out when I refilled and that trapped air is slowly making its way to the expansion tank. It may be that there is still a slight leak. However, I have no idea where this leak may be, but it is definitely not at the joint that I was having a problem with and doesn't seem to be in the cabin. I'll leave it for a while longer and see how things go.

MikeySkiBoy said:

It may be that there is still a slight leak. However, I have no idea where this leak may be, but it is definitely not at the joint that I was having a problem with and doesn't seem to be in the cabin.

Click to expand...

Check the air bleed valve in the heater hose - they sometimes develop a slight weep at this point. Putting the bleed screw in with a dab of silicone sealant will fix it.

Thanks for that info and your ongoing concern. I'll try to have a gander at it this weekend and will report back.

jrkitching said:

I haven't replaced it, but on reading FIAT's workshop documentation, it would appear this job is a complete horror ! It seems you need to remove pretty much everything inside the front of the car, including the steering wheel, airbags, most of the dashboard and one of the doors .

Perhaps someone who's actually done this job can come along and post their story?

Click to expand...

You called




13 hours all in :bang: although there was lunch and a lot of mucking about with the lads in-between

Most Easterly Pandas said:

You called

13 hours all in :bang:

Click to expand...

looks like I'm going to attempt a repair / replacement on ours,

the Factory fitted Mats, did an Excellent job of masking the damp carpets.:bang:

anybody got any pics of access..??,

looks like removing the glovebox to have a peek is favourite

charlie

Good evening folks.

If it is the same problem as I had, I don't think removing the glovebox will do any good. The joint that I had a problem with is located in the passenger (UK) footwell area, right behind the curved lower dashboard fascia, and, unless you can see around multiple corners and through plastic covers, I think you will be stuffed!

Assuming that your motor is the same as mine, you need to get that lower fascia off (easy job) and remove the vertical(ish) rectangular black plastic cover to see the rectangular flanged joint (just 3 screws, I think). If that flanged joint is wet at the bottom, then we might be talking about the same issue. If it is wet, to really check it is the source, dry the joint off completely and then wrap it in kitchen roll (preferably white). Drive the car with the kitchen roll on for a few days (just leave the fascia off) and then pop the roll off and see if it is wet, or coloured with coolant, inside. If it is, then I would put money on it being the same problem (see my earlier post on the details of my fix which seems to have really done the job and is holding up very well). If the roll isn't wet inside, then I am sorry, but it doesn't look like I will be able to help.

If I can be of any further help, please do not hesitate to PM me again.

Good luck.

Mike.

that's great info thanks,
I'll attempt it on Saturday.. let you know how things go..,
Charlie

Most Easterly Pandas said:

You called

13 hours all in :bang: although there was lunch and a lot of mucking about with the lads in-between

Click to expand...

:worship::worship::worship:

If you do have a leaking matrix inlet joint here is the nugget of how to fix that specific issue.

Once I got the system drained down, and as I had already taken off the fascia panel, it was easily then less than four hours to fix the leak. That includes leaving the sealant to cure for a couple of hours and then flushing the system a couple of times with clean water before refilling it with coolant. No need for distilled water in these parts, but you might not be so lucky.

The really difficult bit would appear to be getting your carpet dried out once you have capped the leak. I'm still having to perform occasional inside scraping of the windscreen in frosty weather as there is still a bit of moisture trapped in the under carpet foam type stuff. The leaked coolant has been very reluctant to evaporate away and I haven't been able to get rid of it all yet. Here's hoping for another cracking summer next year so that I can leave the doors open, when I remember to!