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lou's garage

My car was knocking on startup for 30 seconds (like someone knocking hard on a door). It had just been serviced when this started. I took it back to the mechanic who put riser in it, as well as a considerable amount of oil. Found this strange when it had just been serviced. Would I be correct in assuming they forgot to put oil in it?

Glenis G

I’m sorry Glenis, but I don’t know what you mean by “riser."

There would have had to have been some oil in it. If the engine crankcase was completely void of oil, then your low-oil warning indicator light would have been illuminated and making a beeping sound to alert you of no oil pressure before you left the mechanic.

However, it is odd that they added significant oil, and yes, I think it is safe to assume that it was underfilled when you got it back from their service. If it continues to knock on startup, especially when the colder months set in, you may have some unwanted trouble coming your way. Proving any negligence will be difficult. If you are worried, head into your local dealer or reputable local shop, explain what happened and have them perform an inspection. There is only so much of an inspection that can be done after the fact, but at least they can check for any obvious signs of poor workmanship.


My truck’s door-jamb sticker says my tire pressure should be 210 kPa. My factory wheels & tires are P275/55R20. I also have steel wheels and winter tires sized P265/70R17. My question is: Should the tire pressure on the winter tires be set to the same specs as the door jamb, or should it be something different based on different wheels and tires being used for the winter?

Rob L

Your factory tire size of P275/55R20 indicates to me that you are likely driving a half-ton rated pickup from one of the major 3 manufacturers. In most cases, the tire pressure specification noted on the door jamb is for year-round use. There are some exceptions though, however. The softer, more pliable winter tire may cause the driving experience of higher load-rated vehicles such as ¾ and one-ton vehicles to be slightly sluggish and undefined when winter tire equipped. In these instances, an additional 30 kPa may be specified. I doubt your half-ton will require any additional pressure, but check your owner’s manual for any deviation from this norm. Just as a reminder, your tire pressures are to be checked when the tires are cold and more frequently after a significant temperature drop. Transport Canada reports that 23 per cent of Canadian vehicles have underinflated tires by 20 per cent. Underinflated tires lead to poor fuel economy and decreased tire life.

Lou Trottier is owner-operator of All About Imports in Mississauga. Have a question about maintenance and repair? E-mail globedrive@globeandmail.com, placing “Lou’s Garage” in the subject line.

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