White Substance in Cooling System

[Detroit Iron]

I've got a new build.... 360, Edelbrock heads, aluminum radiator, aluminum water pump etc. It's got aluminum parts. The motor has only about 100 miles on it, and I recently disassembled it to balance the rotating assembly which I should have done before putting it together in the first place, but we won't get into that.

I noticed small deposits of white chalky stuff in the water jackets on the heads and various other areas where the coolant flows. In the past, I lost a set of aluminum heads on another motor due to electrolysis. After that I learned that if you have aluminum parts on an engine you should put a sacrificial anode in the coolant. So, that's what I've done with this engine. I have two anodes in this engine.

I don't know if the deposits in this engine are due to electrolysis or maybe something else. I'd like input if anyone has anything to say on this subject. Attached is an example of the deposit in the water pump, and the type of antifreeze I'm using.

 

[nm9stheham]

Could well be the zinc that is being sacrificed. I see the same or similar white powder from the sacrificial anode in the SS water heater in our camper. I bet if you pull one of the anodes out, you will see it already losing small chunks.

Just curious: Did you have a brass radiator in the other engine with the aluminum heads?

I use Zerax G05. It is a newer HOAT antifreeze (hybrid OAT). Similar to what was used by Mopar before their current 10 year OAT antifreeze.

 

[Detroit Iron]

Could well be the zinc that is being sacrificed. I see the same or similar white powder from the sacrificial anode in the SS water heater in our camper. I bet if you pull one of the anodes out, you will see it already losing small chunks.

Just curious: Did you have a brass radiator in the other engine with the aluminum heads?

I use Zerax G05. It is a newer HOAT antifreeze (hybrid OAT). Similar to what was used by Mopar before their current 10 year OAT antifreeze.

That's correct the other vehicle I had the electrolysis problem with was a 340, aluminum heads and brass radiator.

 

[CRUZE 418]

I have aluminum heads, intake and radiator and do not see that residue. It's your anode doing it's thing. I mix green antifreeze and reverse osmosis water and have never had a corrosion problem. You should change your antifreeze at the prescribed intervals.
Not a big fan of the nodes.

 

[Bewy]

I have a alum rad, been on the car 20 years. Iron heads. No signs of corrosion....because I use coolant that has corrosion inhibitor in it.