If You Hear This Sound . . .

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If your car’s engine starts making a “funny noise,” should you be worried?

It depends on the noise!

Some noises are harbingers of real trouble. Others are usually nothing to worry about. Let’s take a look at some examples of both kinds of noises:

* Light clattering sound when you first start the engine – 

A rapid tap-tap-tap-tap (or tick-tick-tick) sound that goes away within seconds after the engine is first started after it’s been sitting overnight (or longer) is usually no cause for concern . . . provided the sound does go away within seconds after the engine is started.

What’s happened is all the oil has settled to the very bottom of the engine and it takes a moment for the engine to build oil pressure; the short-lived noise you hear goes away as soon as oil reaches the parts (typically, the valvetrain) that were crying out for oil. The noise is normal, provided it is very brief – a few seconds – and provided you only hear it at cold-start, when the engine has been sitting idle for awhile. It is most common on cold mornings, when the car has been left outside all night. The oil is thicker and harder to pump, due to the cold.

If the clattering sounds does not go away a few seconds after start-up – especially if it’s present when the engine is fully warmed up – it could be a more serious problem. The first thing to check is the oil level. Pull out the dipstick and look at the hashmarks. If it’s low, that could be the cause of the trouble. If it is low – and the noise goes away once the level is topped off – you’re all set. But remember to find out why it’s low. There is either a leak (look for puddles underneath the car) or the engine is using (burning) oil excessively. It should not be necessary to top off the oil level more than once a month. If you find that you’re having to do that, you’ve got another problem on your hands.

If the oil level is not low, the next thing to check is oil pressure.

If the car has a gauge in the instrument cluster, take a look at it while the engine is idling (never “race” the engine if you suspect mechanical problems, especially lubrication related mechanical problems). Your owner’s manual can give you specifics as to what constitutes a “normal” oil pressure reading for your particular car, but – generally – the needle should be to the right of Low and (in most cases) in the middle of the gauge, between “L” (for “low”) and “H” (for high). If the gauge registers little to no oil pressure and the engine is making noise, turn the engine off immediately. Have the car towed to a shop you trust.  Do not drive it. Do not run the engine at all until the problem is found and fixed. It might just be a bad oil pump, which isn’t that big a deal. But if you run the engine with a bad oil pump, you risk killing the engine, which is a big deal.

If the car has an idiot light for oil pressure, it ought to be illuminated just before you start the engine (key in “run” position) but quickly go out once the engine actually  starts. If it stays on, turn off the engine – and call The Man.

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