(snip) The original head gasket was pretty chewed up. Recently read where, being an aluminum engine, it is vital that the coolant be as silicon/phosphate free as possible - formulated for use in an all aluminum block.
My mechanic says this is the norm rather than the exception when he pulls 928 heads. If anyone has ever used the wrong coolant or left coolant in too long the head gets eaten. Why are so many 928's owned by a slacker somewhere along the line? Anyway, mechanic won't use anything besides Autobahn coolant because that what Porsche dealerships use. Kim Crumb said in Panorama that Zerek Extreme 450 is approved by Porsche. Has anyone else heard this? You know how Red Line is the ultimate synthetic lube, what is the ultimate coolant and why? Please post your coolant opinions and list specific brands and types if anyone would like to discuss it.
There are now other brands that specifically say they are Phosphate and silicon free, and are completely compatible with Porsche engines. My mechanic uses Quaker State which says in bold print "100% Phospate Free." Prestone now makes a long lasting coolant that is also phosphate and silicate free, but the text is in fine print. I guess, they do't want to stop folks from buying the other formula they make, which isn't phosphate and silicon free.
Merry motoring. Ed Ruiz
When I flushed my cooling system last spring, I ended up choosing Texaco's Havoline Dex-Cool Extended Life Anti-Freeze/Coolant. Compared to all the other brands on the shelf at the time, it was the only one that was phosphate and silicate free. The Dex-Cool in the name means that it has met a GM standard for extended life coolants. Texaco's web page has a info on their coolants.
When I was flushed the system in my wife's Mercedes, I went to the dealer for "official" Mercedes coolant. Surprisingly, it
'83 928 S 5-speed (U.S. spec)
Zerek Extreme 450 is available at NAPA for about $11/gal. It comes in a silver container. That lame Zerex guy, no help at all!
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