If You Hear These Noises

By Eric Peters, Automotive Columnist

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.

* Squealing and screeching noises –

Several possibilities here, but the most typical are drive belt troubles (loose or misaligned) or accessory troubles (e.g., a problem with the power steering pump such as low fluid level). Often, the noise will get worse if you rev the engine. Sometimes, the noise is constant.

First thing to do is stop the engine, pop the hood and have a look. Check for signs of leaks and seeps around the power steering pump. This accessory is the only accessory that will have a fluid reservoir with a removable cap or dipstick. If you see signs of leakage — and reddish fluid, which is the usual color of power steering fluid — it’s a clue your problem may be a failing power steering pump. Or failing power steering pump hydraulic lines. If fluid is leaking because of failing lines, the pump will eventually run low, then dry — and it will squeal. Check the fluid level of the reservoir. If it’s low, you’ve likely found your trouble. Topping it off should quiet the squeal . . .temporarily — until the pump runs low again. You’ll need to have it looked at, but it’s usually not a “right now” thing. Just keep spare fluid on hand for top-offs until you can find time to have the pump (and lines) checked out.

If the power steering pump seems leak-free and is properly topped off, the next most likely culprit responsible for The Squeals is a loose or misaligned drive belt (or pulley). A quick test that requires no tools is to buy a can of WD-40 aerosol lubricant (buy a can at any auto parts or hardware store) and — with the engine idling — shoot a light spray at the various pulleys and belts (many modern cars have just one “serpentine” belt that drives all the accessories). If the squeal goes away, you’ve found your problem — and the shot of WD-40 might have permanently cured it. If not, you may have to have a mechanic check the drive belt(s) and pulleys. Either way, this is — usually — not an urgent problem. Just an annoyance. With one caveat: If your car has one of those “serpentine” belts and it fails, you will lose all your accessories, including the alternator — it makes the electricity your car needs to run — and water pump — without which your car’s engine will very quickly overheat and you will be stuck. The one big advantage of older-design cars that have a single belt for each accessory is that you can often continue driving if the belt that failed wasn’t one that drove a critical accessory, such as the water pump or the alternator.

* A “click” noise… followed by no noise at all –

This is usually one of two things: Either a bad battery, or a bad connection. The battery might not have sufficient power to turn the starter motor, which starts the engine (in modern cars, the starting voltage must be above a certain point — as high as 14.4 Volts — or the computer will not allow the engine to start) or there might be sufficient power in the battery but it’s not getting to the starter due to a poor connection.

First thing to try is checking the connections at the battery. Feel by hand whether they’re loose; sometimes, jiggling them will result in a “lights on” (and ready to start) condition, like magic. But it’s not magic. You’ve just uncovered a poor connection — and re-established a good connection. You will probably need to either tighten the cable clamps at the battery terminals, or replace the cables, if the clamps have lost their ability to tightly grip the battery’s terminals It may also be necessary to clean the terminals (and cable clamps). Use a wire brush/terminal cleaning tool for this — which you can buy at any auto parts store for less than $10. Once clean, spray the terminals/clamps with WD-40 (the miracle in a can) which will displace any lingering moisture (that’s what the “WD” stands for) and also leave a protective coating on the exposed surfaces.

If jiggling the wires — and cleaning the connections at the terminals — doesn’t do anything, and the battery is more than two years old, the next most likely culprit for your no-start blues is the battery. But don’t chuck it just yet. First, get it tested. Most auto parts stores will do this for free — and if the battery is dead and did have warranty (most do) you will usually get at least some of your money back in the form of a store credit toward your new battery. Assuming, of course, that you saved the receipt for your old battery. You did save your receipt, right? I always leave my receipts in the glovebox of the car, which is the best place to find the thing if the battery ever prematurely buys the farm.

Next time, we consider some smells — and what they portend.

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