Which coolant for aluminium radiator?

[Diplomat]

I'm a few days away from fitting a pattern radiator made from aluminium. I figure it should last at least until my 1997 Bongo turns into an uneconomical money pit with multiple problems.

In order to maximise its life I need to know what is the recommended coolant to use with aluminium. Up to now I have always used blue/green ethylene glycol in the original radiator. That coolant has always been the cheapest.

The 'A' in OAT stands for acid and I wince at the the thought of acid in contact with aluminium.

What are people using in aluminium replacements and where are they buying it economically?

Thanks


Frank

[Simon Jones]

The core of the original Mazda radiator is also aluminium (as is the head, thermostat housing and other cooling components) so you can continue to use 'traditional' coolant or switch over to the modern long life OAT stuff as long as you thoroughly flush the system. Personally, I went for the Halfords 5 year coolant on the basis that I won't need to replace & re-bleed every two years, and as its bright pink, it's easier to see in the header tank and any leaks in the system would be easier to detect. It also puts down a protective anti-corrosion layer inside the system which is why some people find that need to wire-brush the screw in their coolant alarm after the new stuff has been in for a while.

[Northern Bongolow]

have a read, the first paragraph covers ally.

http://www.coolantexperts.com/coolant_o ... at_coolant.

heres the full breakdown of the differences and uses etc.

http://wiki.seloc.org/a/Organic_Acid_Technology

[Diplomat]

Thanks for both replies. Helpful links and comments.

I should have realised that the existing matrix is aluminium but when the radiator is fully dressed with fans on one face and A/C radiator on the other, it's not something we tend to look closely at!

On balance I will probably stick with the coolant I already have plenty of in stock rather than going over to OAT. For one thing, I know the smell of boiling ethylene glycol (or whatever). This nasal stimulus has always saved my cylinder head since the first weep around the metal to plastic join immediately after which I fitted an alarm. Subsequently I've always smelt it and topped up before the alarm has ever gone off in earnest. I guess OAT has its own distinctive smell as well.

I might shy away from changing to a coolant which brings with it the aggro of having to shine up the alarm contact screws, on the grounds that I hoped only ever to screw them in once and they are better left undisturbed.

One thing I have noticed fairly recently is that the weeping starts as soon as the top of the rad gets hot and it is usually less of a problem once the thermostat opens and the bottom hose gets warm. I've often panicked on seeing a drip underneath after a short drive which cures itself after more driving. I don't think my thermostat is playing up but it takes about a 3 miles (assuming no traffic jams) of undemanding urban driving from cold for the bottom hose to warm up, which it then does very quickly. I may post this observation on one of the threads relating to leaking radiators. The front heater gets warm within the first mile or so, as does the top of the radiator. The bottom doesn't appear to warm up noticeably as a result of cooling the transmission so presumably the transmission cooler is more 'belt and braces' technology than an absolute necessity.


Frank