Radiator Corrosion Prevention

[djmx5]

Hi all,

Is there any way to prevent the reported lower corner corrosion that attacks the radiator?

I'm having the cam belt/wp changed later this week and it seems the ideal opportunity to apply some kind of rust inhibitor if this is possible.

Thanks
D

[martin1810]

Radiators usually corrode from inside.

[ddave05]

Flush the cooling system completely and refill with G12 and de-ionised water ONLY. That is the best prevention. When people start mixing coolants the radiators don't like it.

[Crasher]

The issue with the radiators is in the lower corners where they seem to corrode; there isn’t much you can do about it. Wax will collect muck and melt anyway but I suppose black paint my help. The replacements do seem to do it as badly as the originals.

[djmx5]

Thanks for your replies chaps.........if the issue is corrosion internaly there seems little i can do to prevent it, other than to not mix coolant as has been suggested.

I have wondered if a brush of the lower corners with copper slip would withstand the temperature of the radiator and offer some external protection?

Cheers
D

[David_Cooper]

I cut my old rad apart to see about this- the corrosion had definately started from the outside. I think therefore painting it would help, but as the cost of new (ebay) rads is so low now, it's probably not worth doing unless it's all apart already and you have some paint handy I suppose!

[djmx5]

David....thanks mate I know the parts ain't too expensive, but as a non-spanner man, it's the fitting and so on that I'm trying to eliminate.

I'll ask the chap who will be doing my cb/wp tmrw morning what he thinks.

Interesting that you were able to confim that the corrosion started from the outside.....given that the rad is permanently exposed to water that suggests poor materials from VW don't you think?

Cheers
D

[David_Cooper]

Gotcha, well it certainly won't hurt to paint the exposed bits.

Something that doesn't help is the addition of foam between the rad/ fan housing/ lock carrier which holds water and accelerates the corrosion..

I suppose it is poor materials to blame.. sadly not VW specific, my previous Afla suffered in exactly the same way as this Passat, corroded bottom corners.. :(
Interesting to note- my 1975 Mini still has it's original (copper) radiator!

[dieselbundy@aol]

Gotcha, well it certainly won't hurt to paint the exposed bits.

Something that doesn't help is the addition of foam between the rad/ fan housing/ lock carrier which holds water and accelerates the corrosion..

I suppose it is poor materials to blame.. sadly not VW specific, my previous Afla suffered in exactly the same way as this Passat, corroded bottom corners.. :(
Interesting to note- my 1975 Mini still has it's original (copper) radiator!


my 1975 Mini still has it's original (copper) radiator
thats because it is a proper built classic car i have one too:approve:

[Chipped2]

My 2002 Passat 130 tdi Sports estate radiator failed under Warranty in 2005 and was replaced. It has already outlasted the original by two further years and a heavy badger hit costing £1500 and needing a new bumper, Air-con condenser rad. didn't leak but was 'dished ' by the accident and suffered detachment of some rows of cooling fins. It was replaced with a gold coloured one. The original was silver and quite corroded.

Don't think painting will helpbeing a difficlt area to get to. If I was concerned I would apply Waxoyl to the lower corner while radiator is hot

[passat 130 tdi]

I give mine a good spraying with a hose pipe when salt is being applied to british roads . Same goes for the aircon rad.

[djmx5]

Hi all,

Thanks for your replies on this subject.

Unfortunatley for me my rad was found to be corroding at both lower corners and leaking from the passenger side ever so slightly. Being a bit over 4 years old and 42k miles I wasn't expecting that.

As this was detected whilst the front bumper was off for a cambelt change, i opted for a replacement at the same time.

One thing I did notice and I think was mentioned previously was the foam type insulation that the corners of the rad sit amongst. Knowing how this stuff absorbs and retains water I decided to remove the bottom two inches of the stuff in the hope that this will prolong the life of the replacement.

Time will tell I guess.

Cheers
D