HELP ME PLEASE!!!

[SuperV8]

Guys, for future reference, I've just changed the heater matrix on a Mk3 leon 2.0 tdi Fr.. Fairly straightforward to be fair. Now the car has toasty heating again I thought I'd have a play with the old (blocked matrix) 1) Dissolved a dishwasher tablet in boiling water and filled matrix (has to fill inlet and outlet sides) capacity is minimal. Left to Soak for a couple of hours... note :the face of the matrix wasn't even getting warm 2)Drained and flushed through with garden hose for 5 mins ( after which time water was passing through the matrix. 3) Did a 2nd fill with boiling dishwasher water and soaked for half hour... note: face of the matrix was now quite warm and only had to fill one side to completely fill it. 4) Again flushed with garden hose and water running freely through the matrix 5) To make sure blew through with compressed air (I have a compressor) but probably not needed. I'm now convinced my old matrix is completely clear and wished I hadn't rushed out and spent £165 on a new matrix. So if you have the time then following this procedure before buying a new matrix could save you a Bob or two.

This is only a temporary fix.
I cleaned and flushed mine (using various cleaning solutions - including the dishwasher tablet dissolved in boiling water) 5 or 6 times! Each time it would work fine for a few months - then bam - coolant low warning light.
I was hoping that the time between each of these 'cleans' would get longer and longer to the point I wouldn't have to do it again! but after 5 or 6 I thought sod it and brought a new matrix (June 2021), and glad I did, has been perfect since; 15 months+.
I noticed heater matrix's are very seasonally priced - being £100+ in Autumn & Winter - and mine only cost £35 in the summer!

 

[Mk3 1.4tsi CHPA]

I replaced mine in March following the above video in about 3 hours and that included taking my time.

I've sent instructions to about 3 others members on the same subject so drop me a DM if you need any help with sourcing your matrix, tools, fitting, photos etc.

The matrix is never usually fully blocked but has restricted water flow due to the combination of possible silicant gel from the split bag in the header tank and casting sand from the engine block. You can try to flush it out (I tried 3 times) but compared to a new one, it's never as good.

Hello mate, I was hoping if you had any advises or instructions for this please, are there any specific tools needed ? Any help is much appreciated, Thanks.

 

[BillyCool]

Hello mate, I was hoping if you had any advises or instructions for this please, are there any specific tools needed ? Any help is much appreciated, Thanks.

Hiya,

The You Tube video is very helpful and also some comments from personal experience:

Extra tips:

Line the footwell with thick plastic sheeting and then have some towels and kitchen towel ready. You WILL spill some, although only about 300ml actually comes out of the matrix (it's the smallest of the 3 coolant circuits).

There are 3 screws holding the blower motor in place. The one at the back is hard to get to, so a short T25 (or whatever size it is) on a small ratchet works best. Anything longer is hard to fit in the footwell.

When you remove the glovebox/multimedia unit - label all of the wires and remember (write down) what order things came out. There is a footwell light and glovebox light and it's easy to forget what goes where.

When you re-attach the pipes to the matrix - on the lower pipe make sure that the pipe is fully in and the retaining collar on the back is fully engaged and clips on to the back properly, otherwise it will leak a little (there is a small lip and it need to sit over that).

Also be careful when sliding in the new matrix. They are very easy to damage. Just be patient and take your time. Don't force it if it doesn't feel right.

The coolant circuit on the car is quite complex and you need special tools to fully flush/bleed it. As I was having my water pump changed (another known issue), I just got my mechanic to drop the main rad hose so most of my coolant got changed anyway. I never got it properly (professionally) flushed but it's been fine for nearly 3 years.

I bought my matrix from Europe due to lack on UK stock. Cost me about €90.

The Valeo was what was already in my car:

https://www.buycarparts.co.uk/search?keyword=715303&maker_id=104&model_id=11484&car_id=23695&kbaStr%5B0%5D=YE14WMM

It took me a couple of hours to do and I faffed a bit.

I did take some pictures as well so let me know if you need anything.

Good luck with it.