Some Things Last Forever... But Not Rubber

We often get asked, "What are the main maintenance items I should check on my car?"

Miatas are incredibly reliable. However, a downside is that 25-30 years later they are still running—and often recommended maintenance items get overlooked. We see this a lot at the shop; cars roll in with only 30-40K miles on them, and they are still all original.

So what things should you watch for?

Let's start with NA and NB cars. These are getting up there in years, and there are a lot of parts that will eventually fail due to heat cycles or age. Almost all of these parts are plastic or rubber, the first of which are the radiator and coolant hoses.

If your radiator is no longer a nice glossy black, it's time for a new one! Once it turns brown, it gets very brittle and is prone to cracking like this:

The original plastic radiator should be a bright, high-gloss black. If you could use the words green, brown, or grey to describe the color of your radiator, get it replaced! As the plastic ages, it becomes very brittle. We often see cracks around the upper radiator hose on very old units. Don't risk it!

And if you want to kick up your cooling a notch, use this time as an excuse to replace the plastic tank radiator with an all-aluminum unit. We have been running the Koyorad radiators for years and love them.

The next easy fix is the hoses. If they are not soft and pliable, they need to be replaced. Hard, plastic-like hoses will eventually crack and leave you stranded.

We have tried lots of aftermarket options, but nothing beats the Mazda OEM hoses for reliability and perfect fit. We also have the OEM hose clamps if needed, as we have found these hold up a lot better than worm hose clamps.

The final item usually announces itself in the form of an oil leak or by the car no longer running—the timing belt and front engine seals!

Despite Mazda recommending the replacement of the timing belt every 10 years, most people push it way past that, which is okay—until it breaks. When doing this job, go ahead and replace all the seals and gaskets—you've got the motor apart anyway! Now is the easy time to do it!

So what about the NCs? Well, there's some good news! These cars don't have timing belts, so there's no age- or mileage-critical items on the engine itself to address.

The main item to check on your NC is the coolant overflow tank. Unlike with the older cars, this tank is pressurized and inline with the rest of the coolant system. If it ruptures, all the high pressure coolant leaves... in a hurry! The tank should be a nice glossy white; if it's yellow or brown, time to start looking for a replacement!