You recently gave your mother your 1997 chev ventura van. It started overheating and a Mechanic told me it was all caused by dexcool that GM used on these van. Do u have any info on this?

Answer 1

There have been complaints of this Coolant, but I think most are unfounded. Many motorists are under the mistaken impression that today's extended-life antifreeze products are lifetime coolants and never need to be changed. They are NOT lifetime coolants. The recommended replacement interval for most extended-life coolants is every five years or 150,000 miles, whichever comes first (not last). Extended-life antifreeze has been in use for about a decade, and GM has been using Dex-Cool extended-life antifreeze in all of its cars and light trucks since 1996. With older "conventional" antifreeze products, the recommended replacement interval is usually every two years or 30,000 miles. The same recommendation applies to extended-life coolants that have been contaminated with ordinary coolant. If somebody uses ordinary coolant to top off a system that is filled with extended-life coolant, the additive packages can interact and reduce the service life to that of regular coolant. The trouble is, you can't always tell if extended-life coolant has been contaminated with regular coolant. Most long-life products are dyed orange while most ordinary coolant is dyed green or yellow. But color shifts can occur naturally as a coolant ages, and it takes a lot of cross-contamination to produce a noticeable color shift with some products. The only way to know how often a coolant change is needed is to (1) know what kind of antifreeze is in the vehicle's cooling system (which is often difficult if not impossible to tell), and (2) to check the time/mileage since the last coolant change. One of the best ways to check the condition of the coolant is to use chemical test strips. The test strips change color to reveal both the condition and strength (freezing protection) of the coolant. The test strips react to the level of alkalinity or acidity in the coolant to give a "good" or "bad" reading. If the anti-corrosion additives are depleted, the antifreeze is overdue for a change regardless of time or mileage. Just make sure you use the correct type of test strip for the coolant being tested (regular or extended life). And if you are not sure what is in the cooling system, use a test strip designed for regular GREEN antifreeze. A visual inspection of the coolant is also a good idea to check for sediment or other signs of contamination. Droplets of oil in the coolant might be the result of a leaky ATF cooler or a leaky head gasket. The presence of sediment or rust would tell you the coolant is not doing its job of protecting the cooling system, and a coolant flush or coolant change are long overdue. If the system contains Dex-Cool antifreeze and the coolant is full of red muck (which GM says can occur if the cooling system has not been filled properly and there is air in the system), there is a serious problem that will likely require flushing and cleaning the entire cooling system, and possibly replacing the radiator if the muck cannot be removed. The most troublesome applications have been Chevy/GMC S-10 pickups and Blazer/Jimmy models with the cast iron 4.3L V6 engine. These trucks do not have a pressurized coolant reservoir and seem to be prone to air contamination of the coolant.