Porsche Enthusiasts Club Forum

Hi,
A 944 s2 should have phosphate free antifreeze. If the coolant system has been
completely drained out, can it be refilled with the "newer" red/pink antifreeze?. Or
should the older blue type be used.

Thanx Warren

If by pink you mean long life then yes that is what I'd use. Its around £15 from Halfords. I also used filtered water either from the dehumidifier or from the domestic water filter.

Don't use the OAT (organic acid technology, I think) type coolant in a 944, unless is states it is comapatible with older type systems as it eats any components containing copper and may not be compatible with the hoses either.
The very latest longlife coolant is probably OK as it will mix with both, but the earlier longlife type must not be mixed.

There shouldn't be copper in a 944 cooling system as its an all alloy engine & they are at opposite ends of the galvanic scale.
Just done a google & can't find anything definitive!

Threaded inserts in the rad for the fan switch are brass as are the temp. senders I think?

We tested a lot of cooling system components at work and the instruction was that you should not use the OAT anti freeze in the older cooling systems as they were not compatible. It may also be the hose composition as well as the copper content.
Odd things happen to hoses in automotive cooling systems - Google "brabolyser test" if you fancy some light bedtime reading about corrosion of rubber hoses from the inside!

Red antifreeze (long life) and Blue antifreeze (old standard) do not mix well, the can form crystals and gel as well as becomming a nasty mix.

Example 1
Boxster, filled from the factory with red, topped up by customer with blue. Outcome: Gel forming in radiators and header tank, crystalized buildup growing between flanges and hoses forcing off clips, some degrading of hoses (becomming very soft)

Example 2
944, filled at the factory with old blue antifreeze, topped up under the advice of halfords staff with red anti freeze. Outcome:Blocked heater matrix and radiator.

Example 3
928, filled at the factory with old blue antifreeze, drained and re-filled by enthusiast with red long life anti freeze. Outcome: Following head gasket replacement we found that the cylinder head was suffering with errosion of alimunium within the water jacket, gel forming. Conclusion of rep's from Esso and Mobil agreed that the cause was the acids built up by residue and remaining blue antifreeze within system that didnt drain, reacting with the new antifreeze.

Conclusion.

If you wish to use the red stuff, make sure you take the time to flush the system completely by filling with plain water, running up to temp, draining and repeating until you are sure no remaining contamination of blue antifreeze is likely. Possibly use a cooling system flush to assist.

Other than that, do not mix them. You might get lucky, but do not do it.

Jon

Isnt the issue primarily with aluminium and not metal?