What to Do if Your Car’s Engine Starts Making Weird Noises

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  • Any driver knows that their car making a funny new noise can be an immediate cause for stress, especially if it seems to be coming from under the hood. If your engine seems to be making a new thunk (…or tap, hiss, bang, knock, rattle, buzz, hum, or pop), you may be wondering what to do.

    Your first step should be to stop driving your clunker and get it into a mechanic for a diagnostic. Be sure to ask up-front about the inspection fees.

    Do your best to pay attention to the sound, or get a recording of the noise if you feel you can’t explain it yourself. Pay attention to when it happens — is it only when you’re idling? Or after you’ve turned the car off?

    These can be important in determining the difference between quick fixes and major mechanical repairs. A mild knocking, for instance, might mean you’re using the wrong octane fuel level for your vehicle, where a loud knock could be a warning of a faulty piston ready to destroy your engine.

    Some other examples of sounds and their possible meanings:

    • High pitched squealing that stops when your engine is off can indicate you have a belt that needs to be repaired or replaced.
    • High pitched squealing that is continuous, even if the engine is off can mean a gasket in your radiator may be worn.
    • Ticking, clicking, or loud idling can all indicate that your oil is low, or that there’s an issue further down in your valve train or that lifters have collapsed.
    • Pinging or mild knocking both could potentially mean the octane rating of the fuel you use is too high or too low.
    • Hissing can indicate a leak, or that your engine is overheating.

    Unfortunately, popping, rattling, and loud knocks each could mean a large number of things but absolutely should be checked by a professional as soon as possible. If a loud knocking sound begins while you’re on the road, pull over and request roadside assistance.

    Once you’ve visited a mechanic and gotten an assessment of what needs to be repaired, there are several factors you should take into account for your course of action. If the problem is a quick fix like an oil change, using different fuel, or replacing a bad filter, there’s not much consideration that needs to be made. For major or more costly repairs, you should consider the age of your car and its condition otherwise.

    For new vehicles that have a lot of life left in them, expensive repairs now will work out to be a better value than replacing your vehicle. However, if your car is older or likely to need other repairs down the road, a costly repair now may end up compounding into an even more expensive problem later.

    You’ve probably heard the term “totaled” referring to a car before, but many aren’t aware it’s an insurance term with a specific meaning beyond “badly damaged.” Insurers determine if a car is worth repairing or if it’s totaled by comparing the cost of the repairs to the value of the car. You can use a similar valuation when determining if repairing your engine is worth the trouble of repairing or not.

    A safe benchmark is if the cost of repairs is 50 percent or more than the value of your car, it’s not worth it, though that percentage could change depending on the car or your financial situation.

    Sites like Kelley Blue Book can tell you the local estimated value of your vehicle when it’s in good condition as a starting point in your calculations, but don’t be surprised if you end up getting much lower quotes for the same vehicle while damaged. To get a good idea of what your damaged car is worth, it might be a good idea to look up damaged car sales in your area and see what they sell for.

    If you’ve done the math and found it’s not worth it to have your car repaired, you may be feeling discouraged. The good news is that it’s become easier than ever for people to sell mechanically damaged vehicles for a reasonable price, which is important if you’ve suddenly found yourself in the market for a new car.

    When selling your damaged vehicle, look for a licensed and reputable junkyard or online junk car service. Always look for a guaranteed quote, and never take a “no-value” valuation for an answer.

    If you have the time and know-how, you can maximize your profit by selling some of your car’s usable parts yourself before selling the remaining body for scrap. Your tires, side mirrors, and other relatively easy-to-remove parts have value. Even if it’s hard to say goodbye, you’ll have a nice starting fund for your next set of wheels.