10 car repair red flags to watch out for in older vehicles

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Getting 200,000 miles of use—or more—from a vehicle is an impressive feat, but it’s not impossible. Owners should be aware, though, that as a vehicle approaches that milestone, many of its components will start to wear out.

You’ll see some warning signs, or red flags. Pay attention to them and you can avoid the double whammy of being stranded and slapped with an expensive, unexpected repair.

To help out owners trying to reach that 200,000-mile mark, we compiled estimates of the expenses involved to fix these common problems. Using a 2010 Toyota Camry with a 2.5-liter four-cylinder engine, located in northern New Jersey, as our model car, we used the free Consumer Reports Car Repair Estimator to determine the costs. Powered by CR’s partner RepairPal, it provides regional estimates for repair work; your actual costs may differ. Remember to shop around for the best deals.

These repairs are ordered from the most expensive to the least expensive to complete.

1. Brakes

What are the warning signs? “A spongy or sinking brake pedal can be a sign of a failing brake master cylinder,” says CR's chief mechanic, John Ibbotson. If you live in the snow belt, make sure to check the hard brake lines for rust or weak spots.

Can I do it myself? Unless you’ve worked on brakes with someone else (like helping a parent years ago), this is a job for a qualified mechanic.

What happens if I ignore the red flag? In the worst-case scenario, you’ll have a brake failure and end up in a crash. In the best scenario, you’ll wear the brake pads down to their metal backing plates, resulting in poor braking performance and a loud metal-on-metal noise when you try to stop the car.

CR's best advice: You should have your brakes checked regularly and change the brake fluid as recommended in the owner’s manual. Don’t do the work yourself unless you are absolutely confident in your ability.

2. Mechanical Components Reaching the End of Life

What are the warning signs? Even the strongest original parts can wear out. “Don’t go cheap on replacement parts in order to save a few bucks,” Ibbotson says. “If you replaced worn parts with substandard knockoffs, they might be on their way to failure much sooner than the original equipment.” Slow cranking of the engine can be a sign of a failing battery or alternator.

Can I do it myself? If you're mechanically inclined and used to working on cars, you can probably replace the alternator and maybe the power steering pump. But it’s best to have a mechanic handle the steering rack.

What happens if I ignore the red flag? If your alternator fails, your car has no way of charging the battery. Eventually the vehicle will leave you stranded, either from a lack of battery voltage or because you won’t be able to start it. A bad power-steering pump means it will get more difficult to turn the wheels. Ignoring the steering rack can be dangerous because you might lose the ability to steer.

CR's best advice: Don’t mess around with steering components; get them handled ASAP. And don't ignore a bad or failing alternator. Note that some premium parts may come with a lifetime warranty, so be sure to ask when buying.

3. Noisy Exhaust System

What are the warning signs? “You can tell that your exhaust system is reaching the end of its life because your car will get increasingly louder,” Ibbotson says. Exhaust leaks can be dangerous and should be repaired at the first sign.

Can I do it myself? No.

What happens if I ignore the red flag? Exhaust fumes will eventually enter the vehicle and could make occupants ill.

CR's best advice: You should have a mechanic or a muffler/exhaust shop do the repairs. And don’t go with cheap catalytic converters; they probably won’t last very long and you’ll be back in the same situation in a couple of years.

4. Electrical Components Beginning to Fail

What are the warning signs? “Don’t be surprised if features such as power windows, windshield wipers, and even the instrument panel go on the fritz,” Ibbotson says. “The gremlins can be frustratingly difficult to trace.”

Can I do it myself? The door and window components can be handled by a home mechanic who has experience working on cars. The windshield parts are trickier to work on, but it's still something a competent amateur mechanic can handle. But the oxygen sensors should be replaced by a professional mechanic.

What happens if I ignore the red flag? You may not be able to lock or unlock your door or raise and lower the windows if you ignore those components. Your windshield will be messy and difficult to see through if you don’t fix the washer pump or wiper motor.

CR's best advice: Keeping the windshield clean isn’t just an appearance issue, it’s a safety one, too. Get that handled ASAP. The door and window components are somewhat less important—unless you can’t lock your car manually or the windows are stuck open in the winter!

5. Moisture Buildup

What are the warning signs? If it seems that the inside of your windshield is always fogging up or you are mysteriously losing coolant, it’s likely that the heater core is starting to fail.

Can I do it myself? No.

What happens if I ignore the red flag? You'll notice poor defrosting capability that results in decreased visibility. If left for too long, it can result in the engine overheating, leading to engine damage.

CR's best advice: “Even the smallest pinholes will cause interior fogging,” Ibbotson says. “It’s most likely going to be an expensive repair, because the heater core is under the dashboard.” Use a high-quality replacement unit to avoid having to repeat the repair again too soon.

6. Outdated Shocks and Struts

What are the warning signs? Does your car bounce up and down as you drive down the road? You may need new shocks or struts, Ibbotson says. Uneven tire wear is also an early indicator of this.

Can I do it myself? Not unless you own a lot of tools, are very handy, and have plenty of time. Make an appointment with a mechanic.

What happens if I ignore the red flag? You'll experience poor or dangerous handling, and you could wind up with excessive and uneven tire wear.

CR's best advice: Get it done as soon as you notice the warning signs in order to avoid any safety issues.

7. Failing Radiator

What are the warning signs? “A failing radiator or thermostat can cause the engine to run too hot or eventually overheat,” Ibbotson says. Low fluid levels in the coolant reservoir could indicate a leak in the radiator, engine, hoses, or all three.

Can I do it myself? No.

What happens if I ignore the red flag? An engine that runs too hot can overheat, damaging the internal parts. This could result in the engine failing, forcing you to get a replacement.

CR's best advice: Routinely check and top off your vehicle’s coolant, especially before long road trips. If the fluid level looks low or you see the engine temperature is often very high, make an appointment with a mechanic as soon as possible.

8. Oil Consumption and Leaks

What are the warning signs? Increased oil consumption is common in older cars, so don’t panic if your car seems thirstier the older it gets. But if you think you’re topping off the oil too much, it could be a sign of a bigger leak.

Can I do it myself? An oil and filter change can be done by most competent home mechanics who have the proper tools. But it usually isn’t worth the savings to do it yourself because you still have to dispose of the oil. If you think there's a leak or the oil light has come on in your car, immediately check the oil level. Then take the vehicle to a professional to find out what's wrong.

What happens if I ignore the red flag? Oil lubricates the engine parts and helps dissipate heat. So running out of oil will result in the internal engine parts contacting each other directly and wearing out prematurely. Never changing the oil will result in the engine seizing; if that happens, it will have to be replaced.

CR's best advice: Routinely check and top off your vehicle’s oil between changes, especially before long road trips.

9. Spark Plugs That Haven't Been Changed

What are the warning signs? If you haven’t changed the plugs in 100,000 miles of use, the engine runs rough and misfires, or you have trouble starting your car, you should replace the spark plugs. Buying the right kind and getting the right service can make all the difference.

Can I do it myself? While spark plugs come pre-gapped—that is, there's the appropriate amount of space between the center and side electrodes of the plug—you have to use a special tool to make sure they are gapped to your car’s requirements. If it isn’t gapped properly, the plug won’t make a spark to ignite the gas. Make sure you buy the right type of plug for your make and model at an auto-parts store. With cars built before the 1990s, you can probably do the job yourself. But with most newer models, Ibbotson recommends having the dealer or a certified repair shop handle it.

What happens if I ignore the red flag? You might see your fuel economy and engine performance get worse.

CR's best advice: If maintained well, spark plugs can last 100,000 miles. By the 200,000 mark, you could be overdue for installing a third set of plugs. Make an appointment with your dealer or a trusted mechanic to have the work done.

10. Rust

What are the warning signs? It starts with paint that looks like it has bubbles forming. Once you see even a little bit forming around the wheel wells, hood, trunk, or suspension mounting points, there could be a serious problem beneath the surface.

Can I do it myself? No.

What’s the cost? It depends on the extent of the damage. If you have rust, get several competing estimates on the work.

What happens if I ignore the red flag? You can patch surface rust, but that will only slow down the problem. Replacing body panels on a 200,000-mile car can be expensive. At this point, the clock has started ticking on how much longer you’re going to keep the car.

CR's best advice: Have a professional repair shop check to see whether it’s surface rust or there's a structural weakness that will make your car less safe in a crash.

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