Heater matrix leaking

[pjwhitfield]

Well I say leaking I mean proper ****ing out!

Cars been off the road for over a year, back on now but suddenly I'm losing water at a rapid pace. I topped up with 4 litres and drove 15mile to the MOT centre and when they checked it, it was bone dry so they added another 4ltr.

The passenger side carpets (both front & rear) are literally swimming and that no exaggeration, there is an actual pool in the back.

If I'm driving and it gets too low then we get steam coming out of the vents.

I believe it's the heater matrix but anyone got any ideas on how hard a job it is?

Ps it's a Mark1 C70 (2005) manual 2.0

[Gonzobard]

I believe there is a technical guide on here that provides a description.

[Luxobarge]

Yes, have a look at the article. It's not actually particularly difficult, for sure it's WAY easier than on most modern cars, and plenty of older ones too. Did it on mine in about 2 hours IIRC.

[DaveNP]

It's been a while since I did mine but what I recall is the contortionism required to reach into the car, over the door sill and under the centre of the dash, but not a technically difficult job.
There are a couple of rubber O rings joining the matrix to the pipe work which need replacing, if you don't get them with the matrix they were available from Volvo for a modest price.

[JohnM 855 T5R]

It's a very straightforward job. Small hands and flexible wrists help with the contortionism. Should take around 1.5 to 2 hours.

John

[volvo again]

The hardest part is drying the carpets so they don't smell...might be easier to remove them and dry out the insulation underneath or you'll have that damp musty smell forever

[JohnM 855 T5R]

Originally Posted by volvo again

The hardest part is drying the carpets so they don't smell...might be easier to remove them and dry out the insulation underneath or you'll have that damp musty smell forever

I concur with this. When the matrix went on my C70, even after 5 or 6 weeks, the carpets remained damp. The problem is worsened as they go sticky from the antifreeze residue that just doesn't evaporate away. So it was seats and carpets/underlay out, then repeated washing with a wetvac (luckily I owned one) until they were thoroughly clean. Took about 3 days to dry completely - all a pain, but necessary if you are to avoid smells and the carpets becoming absolutely filthy as the dirt sticks to antifreeze residue.

Regards
John

[pjwhitfield]

Cheers for the heads up folks, I used a wetvac on it yesterday and took (now word of lie) about 2 litres of thick brown water from the front and rear passenger carpets. Had to use the car today on an urgent 10mile round trip, used 6lt of water of which Im guessing 2-3 of them are sitting in the back passenger footwell.

Should a "leaking" matrix do that much in such a short timescale? Im starting to wonder if its a pipe under there thats burst or become disconnected somehow?

[Derek UK]

The plastic tanks crack. Can be a big or small crack so the leakage will correspond to that. If the lower part that you can see when you peel back the covers is brown it's likely an old matrix.
See Robert DIY on YouTube for several how to videos.

[pyro]

I did the matrix on my v70 tdi a few years ago, physically swapping out the matrix is easy, and not badly priced either.
but...


The pipes go through the coupling on the bulkhead which on mine was brittle as f**k. No worries, Ill replace that too... £40 quid from volvo will all washers, o rings etc. But if your car has AC you won't be able to swap the part without dismantling ALL of the dash. So a fix that myself and others have done is to use some 15mm Internal diameter pipe, and just break the bulkhead coupling so the pipes go through and just connect up with two lengths of copper pipe and jubilee clips. and silicone up any gaps left. 15k miles later and its fine.


oh yeah, if you are any bigger than a 6 year old then youll struggle to get in to the footwell. But if you happen to have a second elbow or wrist on both of your arms youll be fine. Most fittings are Torx or star bits including a few that a pretty small.

Hope that helps

Ben