[sixto]

We're losing coolant to the tune of a half gallon in 500 miles, maybe more in traffic. It's leaked coolant from the aft bank head gasket forever but it's getting serious relative to how we use the van. No steam or coolant smell in the exhaust that I can detect. It's time to try a pressure tester, I suppose. Oil consumption and leakage is a steady quart between 5000 mile oil changes. Any thoughts on where I should focus on the coolant loss? The in-laws' 98 GV SE 3.3 had more severe coolant loss cured by a new radiator.

Thanks,
Sixto
97 GC SE 3.3 230K miles

 

[ImperialCrown]

Common leak spot on the 3.3L was where the front (aluminum) timing cover met the cast iron block. The o-rings at that point failed, plus corrosion took place between the old coolant and the aluminum.
Look for wetness, crystallized coolant and dried white drip trails in that area.