Skip to main content
you & your car

You recently said that a car should be driven for a distance that is far enough for it to reach full operating temperature. What distance is that and does it vary with the type of car? I drive a 2005 Buick Allure which has 61,000 kilometres. I mainly drive short distances with occasional long distances. The car does sit in an underground garage for, say, four weeks at a time from January to March, although this year it may sit for the three full months. Should I be doing anything special to the car? You were talking about cleaning our carbon deposits. – Delia

The notion is to ensure the engine, transmission and other components in the powertrain reach a temperature sufficient to cause moisture and other contaminants within the fuel and oil systems to boil off or evaporate.

The length of time and mileage do not really vary with the type of car, but they do depend on how long the vehicle has been sitting and the outside or ambient temperature. I recommend nothing less than five kilometres and preferably 10-20.

Your Buick is new enough that is has only seen a diet of low-sulfur fuel so cleaning it out might be as easy as ensuring you use gas from a company that includes cleaning agents in its fuel. Shell, for example uses a lot of these in its premium fuel so the occasional tank of that will probably do the job.

If parking for weeks at a time, or longer, check tire pressures to ensure a slow leak hasn't compromised your safety. There are a number of other steps to take if parking for longer periods of time, especially in relation to the battery. Buy and use a battery tender, which uses small computer chip to monitor and maintain a proper charge as opposed to a charger which, while keeping it charged, over a period of time will actually cause the battery to deteriorate.

I would also suggest having the oil and filter changed before putting it away for a lengthy period.

Oil pressure gauge

The oil pressure gauge in my 1995 Jaguar XJ Vanden Plas used to go directly to the operating pressure when I turned the engine on. Then it began to go up and fall back to about a quarter of the operating pressure. Now, it sits at zero for a couple of seconds before climbing up to the operating pressure. Do you think the oil pump is failing? – Robert

You do not mention which engine you have, but assuming it is the 4.0-litre inline six, it might be the pump, but a more likely – and less expensive – source of that problem might be the oil pressure sender or switch.

These units were known to become erratic after a period of time and had a high failure rate. So much so that Jaguar came out with a replacement kit, which might not be available any longer. But the units are widely available throughout the aftermarket for less than $50 plus labour for installation.

The switch is located sat the right front corner of the engine block near the oil filter and is easy to get at.

If you have questions about driving or car maintenance, please contact our experts at

Follow us on Twitter @Globe_Drive.

Add us to your circles.

Sign up for our weekly newsletter.

Report an error

Editorial code of conduct