Hi all. Whats happening here please

[edwin]

There does not appear to be a leak, but these crystals form in about two weeks. I have scraped them off before and washed the metal back to clean with warm water, but it has returned. There is no antifreeze in the cooling system yet, just water. But the stuff is dry, and no sign of water or liquid. Any ideas. Its in the garage, no draughts, electric green house heater under the car. Car runs nicely.

 

[jcarruthers2]

Hi Edwin

The forming of this residue is quite common on R4 water pumps. In the winter in particular. However, it would normally form all over the pump. I think it is due to a build up of condensation. Something similar can occur in a localized area due to a leak. The tell tale sign is that it would be a bluish colour (same as the antifreeze). It looks like a new pump and the residue is collecting around that bolt, check for a tiny leak from that bolt.

 

[Barnster]

I've seen this before on other cars and it was from a very fine spray from the end of a hose when the clamp which appeared clamped tight. No dripping or telltale signs of leak, just crusty evidence a distance away from the actual leak.

 

[sdvcatfish]

Hi Edwin.
Surprised somewhat, but hey.
There is Dissimilar Metal Galvanic Action the going on here.
Aluminium and Ferrous causes electric current just like the cathode’s on a Battery.
You have explained (I think), there is no antifreeze installed.
Glycol RX not only protects against frost expansion, but also was designed by Renault to protect their marvelous Cleon etc engines.
Get some Green in.
Ian.