You know that you or your customer might try to replace spark plugs WAY before the should be failing.

You already know a vacuum can be generated in the cylinders whereby engine oil is drawn past the rings and into the combustion chamber. It’s going to cause spark plugs to fail WAY before they’re expected to.

So what about other problems? You may not know this, but internal coolant leaks can foul a spark plug and cause a misfire. The problem could be a leaking intake manifold or a head gasket, and the fouled plug might be localized to one or two adjacent cylinders.

Learn more in my latest installment of Counter Intelligence.