Open the hood on your car, take a look underneath that hood, and you'll see something that is really compact. Lots of stuff in a small space. And you'll notice that there's a lot of sophistication in there. Well what that essentially means is that there's nothing cheap to repair under the hood of a car anymore. 

And that means you have to look at your preventive maintenance differently. You see, cooling systems in particular. Back in the day, you used to take a hydrometer like this, you would pull some of the fluid from the radiator up into the hydrometer, you would first look at the freeze protection to make sure it was correct, then you would look at the color of the coolant—that's the reason you can see through these things.

And if the coolant looked good and the freeze protection was good, everything was fine, you didn't have to do anything. Well, that doesn't work anymore. Now the reason is real simple. What made the coolant change color as it got older, was metal parts—steel parts, inside the engine that rusted. Well look at this. Here we have a modern radiator, it's made out of plastic and aluminum. Neither one of those rusts. Here we have a modern water pump. Again, plastic and aluminum. Look at the engine itself, the entire engine is made out of aluminum; the whole block is aluminum. Most of the parts that the coolant touch is either going to be aluminum or plastic.

So, you may have a situation where the coolant never changes color. So you might be going along, thinking everything is fine, when in reality, the coolant has lost its ability to properly protect the plastic and the metal in the engine, and you have a major repair. A major repair, such as we see right here. This is an intake manifold gasket off of a late model car that never had the coolant flushed. Well the coolant that came out of this engine looked like brand new. Yet, this gasket is completely destroyed because the coolant was acidic. You don't want that to happen. It was a major expense.

So, here we have two coolants. One of these is very acidic. The other is brand new, you can't tell the difference. So what do you do with coolant? Well you check it periodically using coolant test strips, or better yet, just figure out a routine procedure.  Usually two, maybe three years. Flush the cooling system, reinstall fresh coolant of the proper type, with distilled water, and forget it. You've protected the cooling system properly. And if you have a question or a comment, drop me a line, right here, at MotorWeek.