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A person is doing work under a car during a full auto service.

D.I.Y. vs the Pros: When to Tackle Your Own Auto Repairs and When to Seek Help

Arthur C. Clarke, legendary science fiction writer and author of “2001: A Space Odyssey” famously said that “any sufficiently advanced technology is indistinguishable from magic.” While we all understand the inner workings of our vehicles in theory, that Clarke quote might seem particularly relevant to anyone who’s ever popped the hood only to be faced with an incoherent tangle of unfamiliar tubes, wires, and metal. Sure, we’re all well-versed in the delicate procedure of refilling windshield wiper fluid, but many of the repairs and maintenance tasks involved in a full auto service can stymie those who aren’t very confident in their mechanical knowledge. The cost-saving allure of the DIY approach can be seductive, but it’s important to know when a repair is within your comfort zone and when it’s time to get some outside help before your vehicle pipes up to say, “I can’t let you do that Dave.”

Always Do Your Research

Before you begin any repair, it’s important to do a little research to determine if you’ve sent yourself on a fool’s errand. While many tasks can be done on the cheap, some require specialized tools or equipment that just doesn’t make sense for the average driver to purchase for what’s hopefully a one-time job. Others might seem simple at first but are laden with potential missteps that could turn a simple repair job into a big-ticket project. It’s also important to factor in the cost of your own time; if saving some money is your top priority, be our guest, but after a weekend spent huddled under your car, you might regret not just ponying up the cash and letting a professional take a whack at it.

Should you decide to do the job yourself, there are myriad resources online to help drivers gauge repair costs and no shortage of YouTube videos on how to tackle nearly every repair under the sun. A number of websites and forums like RepairPal and AutoMD allow drivers to share common problems with specific makes and models, helping to narrow down a possible list of problems based on previously reported experiences. Below we’ve broken down some common repairs into three categories that will help you determine when to roll up your sleeves and dive in and when it’s time to call in the pros.


Oil changes

With some exceptions, oil changes should be within reach of most drivers. It does involve the use of a jack or ramps, but that’ll be old hat for anyone who knows how to change a tire. Make sure to check your vehicle’s manual for service schedule guidelines, as there are some differences between makes and models.

Other fluids (Transmission, Brake, and Coolant)

Once you’ve mastered the oil change, there are a few other fluid replacement tasks you should be able to tackle. First: confirm that they actually need to be replaced. Coolant, for instance, could appear to be low if checked shortly after the vehicle was turned off as the radiator slowly refills the coolant reservoir. It can also be very hot following operation, so give it at least a half-hour to cool down before attempting any refill or replacement. The fluid replacement process might seem deceptively easy, but it’s important to follow a prescribed method to ensure you don’t forget anything. There are many step-by-step guides available online with handy checklists you can follow to ensure you don’t get all turned around and make a costly mistake.

Spark Plugs

Yes, in general, although they can be difficult to access on certain vehicles. Replacing spark plugs is often the first step in trying to narrow down a specific engine performance issue, so being able to cross this one off the list is an important part of the process. Learn to do it yourself and save your money for those times when it does turn out to be a larger issue that involves a costly trip to the mechanic.

Changing Lights

It is difficult to screw this one up too badly. Some bulbs might be difficult to access, but generally speaking: if you can change a bulb in your house, you can change a bulb in your vehicle. Just make sure you have the right replacement bulb, which you’ll find listed in your vehicle’s manual.

Batteries, Air Filters, and Windshield Wipers

If you know one side of a wrench from the other, these tasks shouldn’t be too difficult. All these components can be accessed and replaced using simple screwdrivers and wrenches and are generally accessible and easy to locate. If you’re not sure if your battery needs replacement, most auto parts stores will perform a free check. Air filters are easy to judge by sight: just pry off the cover, and if it looks like your vacuum after spring cleaning, a new filter is in your future. Wipers should be a little more obvious: when your windshield starts streaking or drying unevenly, it’s a surefire sign that you’re in need of new blades.


A gloved hand is holding a OBD2 diagnostic tool.

Diagnostic Trouble Codes (DTC)

It could be a simple fix, but it could also be something much larger. Today it’s easier than ever to download an app and purchase a $20 OBD2 code reader, but don’t get overconfident. I spent a month last summer trying to track down a code related to my van’s emission systems, going as far as replacing an O2 sensor before a more mechanically savvy friend recommended a frustratingly simple fix: replacing the gas cap. This isn’t the sort of guidance you’re ever going to receive from an OBD2 reader, which is more about providing you with raw data than substantive advice.

Software issues, blown fuses, and faulty electronics can all send you on a wild goose chase, as can entering the wrong make and model. There’s nothing wrong with using a code reader as a form of triage, but at a certain point, only an expert is going to be able to interpret the information in a useful way. OBD2 readers have improved in recent years, though, with a number of start-ups launching apps aimed at providing a more comprehensive OBD2 platform. Here is a handy list of smartphone-based OBD2 apps.

Tire Rotation

This is not terribly complicated or easy to mess up, but you need to know what you’re looking for. A poorly rotated set of tires isn’t likely to cause a catastrophic failure on the road, but it could lead to an uneven pattern of wear that could take years off their service life. Familiarize yourself with different patterns of wear and what they mean about your vehicle’s alignment, and base the specific tire rotation method on this data. One commonly accepted method for tire rotation involves moving your front tires to the rear axle and changing which side they’re on, but this might not be the right approach in every instance.

Before any attempted rotation, check the general wear of your tires to make sure they don’t need to be fully replaced. This is likely the simplest and cheapest vehicle maintenance you’ll ever do, ringing in at a grand total of one cent. Simply take a penny, place it in the tread grooves of your tire, and if you can see the top of old Abe Lincoln’s head, it’s time for a new set of tires.

Serpentine Belts

Different from the timing belt and much less likely to cause major damage if installed incorrectly. While the timing belt does the very delicate job of keeping the camshaft and crankshaft in sync, the serpentine belt is responsible for slightly less vital components such as air compressors, alternators, and power steering. As with any belt, it can be a tight fit and might require a little patience, but this repair should be well within reach for any sufficiently handy car owner. As in all DIY repairs, proper documentation can save lots of time down the road. Take note of how the belt is threaded around the pulleys and either make a sketch or take a photo of the layout. Once again, YouTube is a great resource here, or check out this AutoZone video on serpentine belt installation.


If you’re the type who has to mutter “lefty loosey, righty tighty” under their breath every time you pick up a screwdriver, maybe reconsider fiddling with the thing that allows your two-ton truck to slow down. However, if you have some basic mechanical aptitude, replacing your brake pads and rotors actually falls on the easier end of the DIY automotive maintenance spectrum. Ultimately it’s important to do some soul searching and ask yourself: do I trust my mechanical skills when it comes to braking at 80 MPH after someone’s boneheaded attempt at a merge?



Messing with airbags is a hard no for anyone without some serious mechanical knowledge. Not only are they critical for preventing serious injury or even death in the event of an accident, but Airbag systems are also under tremendous pressure. If inadvertently activated, they could cause injuries and may well total your car. Best leave this one to the professionals and buy yourself some valuable peace of mind.

Timing Belt / Chain

Unlike the serpentine belt, the timing belt or chain should be approached with extreme caution. It might look like a large, innocuous rubber band or oversized bike chain, but it performs the invaluable task of keeping your crankshaft and camshaft in sync. While not impossible to work on yourself, a broken or improperly synced timing belt can lead to some of the most dreaded repairs on the books, from damaged valves and pistons to destroyed cylinder heads or blocks. Replacing the timing belt or chain also requires partially disassembling your engine, which can lead to other unforeseen issues if you don’t know what you are doing.

A close up shows timing chain components.


Another vital system you’ll be well-advised to steer clear of, transmission woes are best diagnosed and repaired by a trained mechanic. Not only are there hundreds of individual components to this system, but even trained professionals can spend hours trying to diagnose which specific part has failed. The transmission is also buried deep within the vehicle, often requiring the removal of other components that you’ll also have to worry about properly replacing. This one is usually more of a headache than it’s worth for even the most mechanically inclined unless they have a two-post lift in their garage.


Unless it’s something very obvious, get this to a garage ASAP. There are a few things in this world that will destroy a vehicle right before your eyes, but an overheating engine is one of them. When temperatures get too high, mechanical components can warp, expand or crack, and even cause a piston to weld itself into a cylinder: a death knell for any engine.

Always Know Your Limits

Car repairs can be intimidating, but many of the easier tasks are well within anyone’s reach with a little practice and patience. It’s important to save money, develop some practical skills, and feel the satisfaction of repairing your own vehicle, but it’s also important to know when to throw in the towel. When the issues start piling up, and you’ve scraped your knuckles one too many times, your local mechanic is there to help. Do your research, ask around for recommendations to find someone you can trust, and you’ll soon realize that a trustworthy mechanic is one of the most valuable tools in any repair kit.