I recently posted about a change to Havoline Dex-cool. Since then, I've run
into this article:
SO... I'll be going back to the green after a complete flush. I had read
quite a bit about silicates and phosphates eating the aluminum cooling
system of the older BMWs and it appeared this was a solution. Apparrently it
may not be the best solution. When I replaced my water pump in April 2005, I
noticed some corrosion under the hoses at the thermostat housing. The
aluminum was being eaten! Since I had recently bought the car, I was doing
maintenance as things happened instead of all at once. Pelican discusses the
Not being an engineer (kudos to those that are!), all the information I
found wasn't specific... just saying "use this coolant." A "WHY" would have
been good. So, older and newer BMWs have slightly different cooling systems,
between the aluminum and plastic parts. My '86 535i has an aluminum vice
aluminum/plastic radiator. It's practically new looking despite its age and
the aforementioned thermostat housing.
I don't recommend the Dex-cool, despite the "no this, no that". I'm doing
the green in a 60/40-ish mix with distilled water like I used for the last
15 years in my other BMWs. It gets changed every 2-3 years with 3-4 month
checks on the system anyway. All this was necessary because I never saw
anything DEFINITIVE on the issue. Learn from my mistake (no damage!).
Fred - no harm, no foul. Here is my correction.