Is DIY Car Repair a Way to Save Money or Better Left to the Pros?

Why DIY car repair is so popular right now

If there is one thing nearly all Americans are worried about these days, it’s money. We hear the news every day—no job growth, more foreclosures, skyrocketing rents, lower loan approval, factories closing down, no jobs for new graduates or unskilled workers, and so on.

Because of this, people are looking for more and more ways to save money, especially when it comes to our vehicles. For some people, this means keeping their cars longer. In fact, according to Polk, a leading global automotive market intelligence firm, the average age of cars and trucks currently on American roads is 10.8 years. Overall, average vehicle age has been steadily increasing over the past five years.

Another way people are saving money is by putting off maintenance and repairs. A Consumer Reports study released in December 2011 stated that “Forty percent of respondents who are involved in repair decisions stated that they are postponing car maintenance or repairs on their primary vehicle.” Of those who did put off work on their cars, “Forty-four percent … also admitted that they felt the value, safety, or reliability of the vehicle would suffer, with some saying the car was becoming an embarrassment.”

That is a lot of people. And putting off repairs that could affect safety and reliability just because of money is worrisome.

So, what can you do about it?

One option that many are turning to is the Do-It-Yourself route for repairs and maintenance. In this article, we are going to explore the pros and cons of DIY car repair, figure out what is safe and what isn’t safe to do on your own, and whether or not going the DIY route is less expensive than taking your car into the shop.

How much do people really know about cars?

Cars are complicated machines and they just keep getting more complicated. It used to be that you could open a hood and readily identify most parts in the engine. Nowadays, when I open the hood of my Hybrid, I can barely figure out where to add the washer fluid. The inside of my car’s engine compartment looks more like a rocketship than a gas-driven vehicle.

Cars used to be composed of mechanical parts that you could hold in your hand and fix with simple tools. But just in the past few decades, cars have advanced to the point where they are almost completely run by computers. It's like the difference between those clunky cellphones on 80s TV shows to the iPhone 4G—today's vehicles have advanced just as rapidly.

These days, technicians spend years training to learn how to fix today's cars and continually update their education to keep up with technology. Watching your dad change a tire or helping your friend change his oil only takes a small amount of auto knowledge. Most of the time, this limited knowledge is not enough to tackle more complicated repairs.

But don't worry, there are still repairs you can do and we're going to help you figure out what repairs are safe and relatively simple to do yourself and what repairs you should leave to the pros.


What are "safe" DIY car repairs?

Here are some simple things you can do yourself without too much trouble.

  • Replacing wiper blades
  • Checking fluids and tire pressures
  • Replacing head light and tail light builbs

The next step up would be jobs like these.

  • Changing a flat tire
  • Replacing air filters
  • Changing your oil (though disposing of it properly should be taken into consideration)

The more repairs you do, the more knowledge and experience you will gain, and with this confidence, you can start doing more complex jobs like these.

  • Replacing belts, hoses, spark plugs
  • Replacing starters and alternators

If you are going to do DIY car repairs

I spoke with Bret Bodas, RepairPal’s resident expert and ASE Master Technician, to get some advice on things you should do prior to attempting a repair. Bret's major point was, whether you’re a professional technician or a beginner, to ensure success, you should be prepared. Here’s how:

Diagnose the problem correctly
Misdiagnosis can be a problem. If it can happen to the best mechanics, it can happen to you. If you replace the wrong part, you may end up wasting time, money, and possibly adding to the original problem. What might have cost $100 at the shop could now run much higher. Our advice with diagnosing car problems is simple—never guess what is wrong. Instead, we recommend that you go to a shop and have them do the diagnosis, so you'll know for sure what the next steps are. Or, we recommend following proper diagnostic procedures set out in your owners manual.

Research the repair
Thoroughly research the job you are going to perform. Vehicle repair manuals have never been less expensive and more accessible than right now, so we strongly suggest getting one. You can also consult your owners manual, online information, and instructional videos before starting the repair. After researching the repair, you should have a good understanding of the tools and equipment needed to perform the repair, as well as the difficulty and time needed to complete it. 

If you want to check out online repair manuals that will provide you with the exact information used by the pros, check out Mitchell and AllData.

Make sure you have the right tools
Make sure you have the right tools for the job, but be careful here. Without the proper tools, some jobs are near impossible or can add hours to a repair. Reading the repair manual will provide you with a list of what is needed.

Make sure you have time to perform the repair
Make sure you have the time it takes to perform the repair. You don’t want your car disabled when you need it, so leave yourself enough time to complete the job and also address any issues that will inevitably occur. For a good gauge of the time it takes, the above mentioned repair manuals list the time it takes to perform each job—we suggest doubling that time just to be on the safe side. Having an open, nearby parts store during the repair is highly recommended, too.

The bottom line
If you don’t have the knowledge, skills, preparation, and time to do the repair, it's safer and probably more cost-effective to go to a shop.

When is DIY car repair off the table?

You probably aren’t going to destroy your vehicle or injure yourself replacing wiper blades, but there are a lot of repairs that can be dangerous to yourself and the vehicle. If some repairs aren’t done properly, you can injure yourself while replacing the part or while driving. Here are some repairs that are better left to the experts.

Safety-related repairs
Working on any safety system on the car must be approached with caution. This especially includes the brake, ABS, airbag, or steering systems. Failure to correctly repair these systems cannot only injure you, but others on the road, and that's not worth the savings you're trying to achieve. Suspension systems are particularly dangerous because they are under a lot of pressure due to the springs, and they require special tools to fix. If you have any reservations about working on these systems, we strongly suggest you take your car to a professional.

Additional repairs you should never attempt at home

Timing belt replacement
We have seen too many DIYers damage their engine when performing this repair incorrectly, so be very careful

Transmission maintenance or repair
If something goes wrong here, you can damage your transmission, which can be very costly

One of the easiest ways to do serious damage to your engine is to let it overheat, so rather than risk it, take your car into the shop to deal with an overheating issue

Replacing suspension parts 
As mentioned above, proceed with extreme caution and make sure you have the right tools

Fuel system components
Failure to properly reconnect fuel lines or components can cause fuel leaks and possible fires

Check Engine Light
Many things can trigger the Check Engine Light, so this one is best left to the pros

Additional items to be aware of

Never open a cooling system when the engine is hot, not even to check the fluid level, period. The fluid is near boiling temperature while the engine is hot, so do not touch it until it has sat for at least 30 minutes. Do not work on an engine that is running. There are a lot of moving parts and it only takes a second to seriously injure yourself.

The trouble with trouble codes

If any one thing has instilled the DIYer with false confidence, it’s the code reader. Sure, it’s a pretty empowering feeling to pick up a code reader from your local auto parts store, hook it up, and get that number (called a diagnostic trouble code or "DTC").

As soon as people have that number though, they assume they know what part they need to replace. Sure, maybe you’ll get lucky, but you could end up replacing a part that didn’t need to be replaced that could lead to replacing more parts and the problem could still exist. As Bret Bodas told The Car Connection in a June, 2012 article, “following code readers alone is a recipe for emptying your wallet and filling up your driveway with problems.”

Obtaining the trouble code is a small part of what a technician does in order to diagnose a problem with your car. To show you what I mean, I asked Jim Taddei, another RepairPal expert ASE Master Technician, for an example.

Let’s say your code reader spits back Code P0135 - O2 Heater Circuit Malfunction (Bank#1 Sensor#1).

First of all, you will need to know the location of this sensor. In this case, Bank #1 is the part of the exhaust system receiving the exhaust from cylinder #1. Sensor #1 is the sensor closest to the cylinder head, commonly found in the exhaust manifold but always before the catalytic convertor. Got it? (If you are following so far, great. As for me, I got lost at Bank#1.)

Here are the reasons why Code P0135 could be set

1. The sensor heater must have electrical power and ground to function, so a blown fuse will cause a lack of electrical power. Damaged wiring or electrical connection problems can also cause a loss of either power or ground.

2. If a software issue is causing the code to set, you will need to update the software.

3. An internal fault with the control module could cause the code to set.

4. The oxygen sensor could cause the code to set.

To sum it up, Code P0135 could mean a blown fuse, damaged wiring, electrical connection problems, a software issue, an internal fault with the control module, or the problem could be with the oxygen sensor. The truth is, 95 percent of the time, it is the oxygen sensor, but if your problem falls within that 5 percent, it could take days for you to diagnose the problem on your own.

The possibility of multiple probable causes is true for literally every DTC retrieved from the on board diagnostic system, so we strongly suggest going to a qualified repair shop that is equipped and trained to diagnose these systems.

In Conclusion

No matter what your skills are, unless you are a highly trained and skilled mechanic with the right tools and equipment, you should not attempt most repairs at home. You could end up destroying your vehicle, or even worse, injuring yourself or someone else.

Jim Taddei puts it well: "If you have a hard time putting together IKEA furniture, most DIY car repair is probably out of your league." But with the right tools, preparation, education, and time, there are some repairs you can do at home, and it's always a good idea to familiarize yourself with your car. So, stick to the simple things and leave the rest to the pros. Best of luck!

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