Owners Tips

Lesson Learned: Air Filter Blunder Could Have Cost Whole Engine

Welcome to Lesson Learned, a column where we highlight a story or situation that reinforces the need for drivers and shoppers to understand their vehicle, how to maintain it, and how it works.

Today, we have a tale of an air filter blunder spotted by our thorough technician, thankfully before it caused any serious engine damage.

We’re not sure how this keeps happening, and neither does John Kennard, an automotive technician who often has a good story about maintenance or repair-related blunders.

“I don’t see this all too often, but most of the times I have, have been fairly recently,” Kennard said. He shows me a photo of a rectangular air filter sitting in a non-rectangular airbox: a sort of “square peg in a round hole” scenario, if you will.

They teach us this when we’re three years old.

“Must be today’s fast-paced lifestyle,” Kennard added.

In any case, the offending vehicle wound up in Kennard’s shop for a winter tire swap and oil change when the ill-fitting air filter was discovered.

“New customer this time – not a vehicle we’ve sold or serviced here – but they called up last week for tires and an oil change.”

After performing that work, Kennard gave the vehicle a once-over, inspecting various other parts and components before turning it back over to the customer.

“For some people, the car’s only up in the air once or twice a year, so you want to really use that time to get up close for a good look around for any trouble,” Kennard added.

“We’ll check the fluids, the battery, the exhaust, brakes, suspension, all the rest, and even the air filter.”

That’s when he had a chuckle after noticing the wrong-sized air filter.

When Kennard found it, the engine in this vehicle was inhaling unfiltered air full of dust, dirt, soot, and other contaminants. Over time, these could build up in the engine, causing problems with the intake system, valvetrain components, and accelerated engine wear.

Eventually, breathing dirty air will destroy your engine. Left unchecked, that may have been the outcome here.

When the customer returned to pick up their vehicle, Kennard showed them what he’d found.

The customer was actually aware of this ill-fitting air filter, having installed it himself just a week or so earlier and figuring it was no big deal.

After Kennard demonstrated the problem, the customer was rightfully embarrassed.

“Poor fella was trying to save a few bucks,” Kennard chuckled. “Young guy with a family and all that. I guess he figured he could just use a cheaper filter style or something, so he tossed that in.”

Kennard explained that, in this state, the vehicle was at high risk of a very large repair bill, possibly including a tow truck ride to his shop for a new engine. He also explained that the proper filter was easy and relatively affordable to source and install.

“So, we got the new filter in and set him right up. I think it was another $30 or so, but now his engine’s safe again.”

This story teaches us three important lessons.

First, remember your shapes.

Second, if you’re not sure, leave it to the pros.

Third, remember Kennard’s advice and maximize any time your vehicle gets in front of a technician with a thorough inspection, which should give you maximum peace of mind. Just remember that every service centre is different, so be sure to ask about what is inspected and what isn’t whenever you’re in the shop.

After all, sometimes a keen eye will spot a small problem before it turns into a big one.