Antifreeze vs. Aluminum

I just something that just blew my mind in Motorcycle Consumer News. Don't use antifreeze containing any kind of silicon in aluminum blocks.

This can't be right, because I got on Prestone's website, and they specifically said they put silicate (or silicon, I can't remember) in their antifreeze for aluminum blocks.

What is up with this? I am going to go home and look closely at my antifreeze bottle before I start up my bike - which is still not running by the way. Beast from hell. :evil:

I just remembered - most people on here have air cooled engines. Still - maybe somebody can speak to this.

 

I don't have a Maxim-X but had a Vmax for many years. One of the problems with silicates is the accumulation of sediment and the tendency for the coolant to go alkaline. If left in too long it will cause seal failure in the water pump and a bit of corrosion.

If you change the coolant once a year it won't be a problem. I have used Prestone Low-Tox (PG based) in my Vmax and my 924S (aluminum block) with no ill effects.

 

I am from a VW background (water-cooled is the only way to go comfortably with those things) and I learned early on that you wanted to avoid antifreeze-containing phosphates (which is a material that will act like salt in water) because of electrolytic erosion. I run Sierra mixed with distilled water and change every two to three years. I saw a trick for testing for the anti corrosive properties were one would read from one lead (positive) immersed in the coolant and the other lead on the negative terminal of the battery. As I recall the reading of more than 0.5 VDC would indicate a breakdown of the coolant and required it's replacement to obtain optimal coolant efficiency and protection. It has been a while since I reviewed that bit so I'll try to pop in on it tonight and ensure I've got the voltage correct. I do know for certain you don't want to see more that one volt, that would indicate electrolytic process was occurring (aluminum head+steel parts+coolant with minerals in it=corrosion). Remember tap water will have minerals in it too so you want to purchase distilled water for your radiator. I've read somewhere that distilled water hasn't free ions available to sacrifice in a chemical process to prevent corrosion. I'm not on board with that point of view as the fewer free electrons, the less potential exists, ergo minimal electrolysis. I'm not a chemistry major so I'll defer to the next logical opinion from someone who can bring knowledge to the fray. I would tend to agree that one would want to have minimal silicates in the slurry as it will tend to slime up your coolant passages especially with time and neglect (when is the last time you thought about your coolant?). I like the idea Michael uses, change often.

 

What is Sierra?

I would like to believe in my perfect world that since there are so many aluminum blocks out there today that antifreeze manufacturers take this kind of stuff into account!

I am more likely to be on the side of change often, and you won't have to worry about it. It really isn't that expensive, and you don't have to worry about doing flushes and causing leaks later on.

Besides - its a motorcycle! And with no fairings at that! With a centerstand! If we are too lazy to change the coolant, then we shouldn't be driving it anyway!

 

Yes, I'm a little lexdixsick, I meant dyslexic. Sorry, I'm having a day. There is a great deal of thought put into the creation and formulation of these products, the trick is to find the right one. Prestone is fine for larger V-8's and such where you have the cast iron throughout the motor. You can spring the high dollars for the stuff from the manufacturers or you can do a little homework and save yourself a bit of change. I use the Sierra because it is one of the few on the market that is phosphate free. Good luck to you Rich, you have the right spirit!