Owners Tips

Goof of the Month: What's That Noise?

Originally published on Autos.ca on May 11, 2015 (Goof of the Month: Stories of the Mechanically Declined - What's that noise?)

Welcome to Goof of the Month! Every month, we’re going to ask for stories from our network of mechanic pals which highlight the need to understand one’s vehicle, how to maintain it, and how it works. We read the submissions, check out the stories, and pick the winner, announcing the monthly Goof in our regular column about the most mechanically declined folks on the road today.

This month’s genius came to us from mechanic Nick Labrie, who says his client was mere moments away from needing a new engine.

The Complaint

“Hello, my Chevrolet Cobalt is making a funny noise. I think the rad fan is hitting something while it’s spinning. Can you take a look? I have to drive it out of town this weekend.”

The Mechanic

“This individual came in with a fairly minor-sounding issue. Sometimes, a piece of debris or a broken fan shroud can cause a noise like that. I’ve seen it before. So if that’s what it was, it’d probably be a really cheap and easy fix. But this wasn’t the case, this time. In fact, this customer was lucky she didn’t need a new engine.”

The Diagnosis

The rad fan was just fine. After checking it out, Labrie started the engine to see if he could catch the sound in action. Once the Cobalt fired up, the sound came on right away. “It was like a really, loud, high-frequency banging noise. The kind that makes you shut the engine off right away, because it sounded like something was seriously wrong.”

Upon further investigation, Labrie determined that the Engine Oil light was on, and that the engine had virtually no oil in it. Sometimes, engines consume a bit of oil between oil changes, which is normal. Skip multiple oil changes, and your oil supply can eventually disappear.

The customer said she had been driving the car like this for a week or so, ignoring the oil light because she wasn’t sure what it was. The banging sound was the pistons and rods and crankshaft knocking violently into one another, with no lubrication or cushioning. This is a near-fatal situation, and it’s surprising that the engine didn’t explode like the White House in that scene from Independence Day.

The Outcome

Left unattended, this engine could have seized up and ended its life dramatically at any moment. If it had happened on the highway on the customer’s trip out of town, it would have presented a serious safety concern, not to mention a very expensive bill for a new engine and tow-truck. Though this engine likely suffered some internal damage, the customer left happily after a new filter and a fresh supply of oil stopped the noise.

Lesson Learned

Cars require a fresh and full supply of oil, and drivers need to check that oil level, and its condition, periodically, to avoid issues like these. This month’s Goof scores big points for hearing an unusual sound and seeking to have it looked at ahead of a road trip, but she loses out by ignoring the Engine Oil warning light, which indicates that there’s something seriously wrong. This is your engine’s way of telling you to take a closer look, and drivers are advised not to ignore warning lights in their instrument cluster, unless they’re fond of pricey repair bills. Consult your owner’s manual for information about oil-change intervals, and ask your mechanic if you’re in doubt.