New technologies sometimes encounter disastrous results when pressed into service before all of the kinks are worked out, and nowhere is this more prevalent than in the automotive industry. The landscape is littered with ideas that make sense on paper but fail miserably when pressed into hard service at the hands of the consumers in this industry.

Over the last couple of decades, alternative materials have found their way into automotive applications with varying degrees of success. One of the most popular items that has benefits for both the manufacturer and the consumer is plastic – items made of plastics can be shaped into so many different components at a lower cost than corresponding alloys.

But when the manufacturer doesn’t get it right, the results can be nothing short of horrific. The end result often turns into unhappy customers, recalls, increased costs, and a big fat black eye when they screw it up.

The Chevrolet 4.3l V6 and 5.0L and 5.7L V8 CPI Vortec engines were notorious for composite intake manifold gasket leaks at the front corner on the driver’s side, and just doing a quick google search brings up pages and pages of message-board threads from frustrated owners looking to solve the problem.

This particular mechanic just happened to have a camera handy while diagnosing the leak on this S10 Blazer – check out how the water used for diagnosis is just pouring out of the engine!

From the information we were able to uncover, this appears to be a problem that rears its ugly head about every 80,000 miles on those vehicles and is caused by the different expansion rate between the cylinder head and the intake manifold.

Eventually the gasket becomes deformed and the manifold leaks coolant. Never fear, though. If you’ve got one of these vehicles the how-to’s for repair are easy to come by. There is a new style of gasket made by FelPro, and the plastic manifolds themselves sell for reasonable money.