Michael,

Running 100% coolant is to me a terrible idea. The heat transfer to a 100% solution is not as efficient as you might beleive. Follow the recommendations of Bentley, the authority on the cooling system. Until perhaps recently, water is/was the best heat collector/transporter from the metal of the engine to the cooling radiator. Coolant (antifreeze, pump lubricant, coorosion inhibitor) by itself is not very efficient for heat transfer. Only needed if you are in some God-awful place like Umiat, Alaska in winter where it gets 60-70 degrees below zero. Then thermal inefficiencies don't matter. At that point you are trying everything possible to keep the engine warm enough to run.

If you really want to do some good in the cooling department, go to a 50/50 mix or per Bentley, then add a bottle of Red-Line Water Wetter. The Redline stuff is a wetting agent that brings about a greater surface contact of the water in the coolant to the surfaces of the cooling system. This enhances heat transfer both from the hot engine to the coolant and then from the coolant to the radiator to the air passing through it.

Just my view based on what I have learned over time about the science thermodynamics, how my van works, and how to take care of the van.

Luck,

John Rodgers 88GL Driver

michael schiesser wrote:

> John, I used to always mix coolant with water, especially in the summer to > increase the heat capacity of the fluid, but my a vanagon mechanic told my > always to use straight stuff, and thats waht I've been running on for years. > (not to say I haven't had any probs with the cooling system, I ahve had lots > of them. Does anybody have a solid recc on what are the conseqences of a > 100% coolant ration vs 50/50 water. > > I'm also interested in the recent posting on the non-aqueous coolant that > ?decreases head corrosion? > > Michael Schiesser > 89 Westfalia > Seattle WA > Coolant to water ratio is out of balance. I can't say enough about this. > >You > >have to have the right amount of coolant in the water for the resistance > >between > >the contacts on the low water level sensor to be correct for proper > >operation of > >the sensor and warning light. Of the top of my head, I think I recall that > >it > >must be a 50-50 ratio. If the coolant is old, it can have it's effect. > > > >Coolant is no place to be chincy on the Vanagons. It's not THAT expensive, > >and > >good coolant helps keep the internal working of the cooling system free of > >corrosion and increases the life of the coolant pump. I now use > >bio-degradable > >DexCool (orange color) in mine - good for two years - , and I bleed the > >system > >with the tail end up. Procedure works great for me, and I don't have to > >hassle > >the bleeder valve up front. > > > >Hope this helps a bit. > > > >John Rodgers > >88GL Driver. > >