Heater Matrix

[jasper5]

I have a smell of coolant/anti freeze in the car after the engine warms up which is usually the first sign of a leaking heater matrix.

I haven't checked yet, but I'm pretty sure its on its way out....has anyone got a method of replacing the matrix on the 406?

I have replaced many of these over the years, but not in a 406 so a quick run through of how to avoid getting into problems would be great if anyone can help.

Thanks

I've done a search, but didn't find the answer.

[mjb]

I have vague recollections of someone saying it's possible without removing the dash, and that's all that springs to mind I'm afraid

[Doggy]

I'm sure you know this, but a minor coolant leak under the bonnet can give you the same smell. I had one on a petrol Montego that I literally spent years chasing, then one day I happened to be watching as it warmed up and the thermostat opened. It leaked at the top/hose radiator until the plastic radiator pipe heated and deformed to seal it again - took about 5 seconds start to finish.

Bearing in mind changing a matrix can be a ball-ache, I would wait for either steam from the vents, or sticky deposit on the screen bfore diving in there.

I seem to remember reading, (on here)? that changing the matrix is much harder on one version, (LHD/RHD), as the column isn't in the way. I think RHD cars are easier, but I'm probably wrong.

[jasper5]

I think I can get it out with glove box out, but maybe i'll wait a little while to confirm a leak.

[mjb]

I seem to remember reading, (on here)? that changing the matrix is much harder on one version, (LHD/RHD), as the column isn't in the way. I think RHD cars are easier, but I'm probably wrong.

On RHD 406s, The coolant pipes go through the bulkhead passenger-side, so yeah I imagine we'd have it a lot easier for once

[steve_earwig]

It's in Haynes, on LHD cars you need to remove the steering column, on RHD cars just the glovebox as Doggy guessed. I can transcribe if necessary but basically it's drain the system or clamp the hoses, hoik out the glovebox, lower some sort of cover which I don't think mine has (being a left-hooker), undo the pipes (Haynes says you'll need new sealing rings), undo their clamp bolt, disconnect the pipes and be ready to catch any remaining coolant, then undo the bolts holding the matrix and slide it out.

Although, seeing as how often this has come up before, I reckon waiting for the problem to become more apparent is probably a good idea...

[Quinny]

I know some people are going to shudder when I say this, but on the wife's Xsara HDi, her matrix started to leak in 2012, and I put a bottle of K Seal into the system, and it hasn't leaked since.

[ally406]

Here you go, doesn't look too bad of a job:

CbRZS0YKyd8


....I got a borescope camera for my Christmas, so was able to put that in between the carpet and trim, and see my leaking matrix






....apparently it's usually the o rings that fail rather than the matrix itself. Likely I'll be tackling this one evening next week.

[jasper5]

Brilliant

Thank you very much, that's great

[Harshan]

heater matrix of most of the 406s, here in SL are disconnected. It's there till it starts leaking and then never bother to fix it but by-pass the water lines excluding the heater matrix.

If you need heat by any chance, there's so much outside..

[steve_earwig]

That's a bit mad, equipping cars in countries where you'll never need them with heaters. Still, there's always a chance you'll go mad and drive up to the Arctic circle

Looking at Frank's (brilliant) vid there I do remember seeing in Haynes that you might have to saw off some plastic, I didn't realise it was part of the dash though

I too have a borescope There have been so many times in my life when I thought it would be something I could use (looking inside box sections, behind wall panels without having to remove them etc.) however... I've had it for 3 years and, apart from looking at my fillings in order to test it, I've never used it for anything serious Ah well, it was an ebay cheapy, it's got no screen (them's the expensive ones) so it goes into the laptop on USB.

[Welly]

I can't really remember anyone having to replace a Matrix on a 406 (its not 'common' anyway) but what I do know is that the Matrix usually suffers the effects of excess pressure first. This makes me wonder if the Radiator up front is performing properly? it might need flushing out or replacing, if the car has stood for a long time then the rad might be full of crud.

[steve_earwig]

I dunno, that's 3 we've heard of just on this thread. Just goes to show if you sell enough cars anything you can possibly think of can go wrong on at least one of them...

I've had it for 3 years and, apart from looking at my fillings in order to test it, I've never used it for anything serious

And then I realised I could use if for chasing the igniter wires through the cooker hob to see if they unplug or if I need to replace the whole lot - they unplug

[MacWomble]

I've also had to change the heater matrix on my 2.1 estate. There was no doubt what the problem was, I had water coming out of the centre console vents beside the handbrake.
I didn't change it my self but the mechanic who did changed it by removing the glove box. Said it was straight forward.
My Renault 5 Turbo had the same problem, (they are known for matrix leaks), I had to remove the entire dashboard . Bloody nightmare, took me 12 hours.

[dirtydirtydiesel]

I have found through experiance that they don't like being left standing unused ,
The o-rings on the pipes dry out & perish & when you start using the car again & the pressure builds up & hey presto they start to leak .
I.I.R.C Jasper this car had been staning for a while before you revived it .