10 Car Repairs You Should Never Do Yourself

By: Jack Sackman

With the rising cost of car repairs, a growing number of people are taking matters into their own hands and fixing their vehicles themselves. They are helped by countless “do it yourself” videos posted on YouTube and other websites. While this makes sense in certain situations, it is not always advisable for people to repair their own cars. It really comes down to what the problem is and what fix is needed. Sure, most people can replace a spark plug or install their own winter tires. Heck, most of us can even change a car battery or remove the rust from our brakes. But the truth is that some repairs should be carried out by a licensed and certified mechanic. For safety reasons, if nothing else. Here is a list of 10 car repairs you should never ever do yourself.


10. DVD Player or Upgraded Radio

A lot of people will look at this one and think “Please. I can install my own radio.” The problem here is that installing either a DVD player or a radio involves electrical wiring. And if you’re going to take this task on yourself, you had better know what you are doing or risk doing some serious damage to your vehicle. Dangers include short circuiting the electrical system in your car or causing an electrical fire in the vehicle. There’s also the frustration of wiring the whole system up and then finding out it doesn’t work. Taking your car to a mechanic and getting them to sort out the mess will be more expensive than if you just had a qualified mechanic install an upgraded radio or DVD player for you in the first place—usually at a cost of between $500 and $1,000. Or, you could simply go to Walmart and buy a portable DVD system that your kids can use in the car for around $100.

9. Timing Belt

If you own your car long enough, eventually the timing belt will need to be replaced. And while many people attempt to do this replacement themselves, it is never advisable. That is because A) the timing belt is an essential component that keeps your engine operating, and B) it will require about half of your car’s engine to be disassembled to get to the timing belt that needs replacing. Even if you manage to successfully replace the timing belt, the chances of you reassembling the engine perfectly are slim at best. The slightest mistake could do long-term and irreparable harm to your car’s engine. Replacing a timing belt before it breaks usually costs $500 to $1,000. Replacing a timing belt after it breaks could cost $2,000 or more if it has led to damage with the valves, pistons or water pump under the car’s hood. The cost to fix an engine you screwed up while replacing the timing belt yourself could be significantly more money.

8. Shock Absorbers

A lot of “do it yourself” types like to think they can fix the suspension on their car and replace the shock absorbers themselves. Don’t do it! First of all, if you get this repair wrong it could be a serious safety hazard for your vehicle and make it unfit to drive. Second, climbing underneath your car to replace the shock absorbers can be dangerous in and of itself. Many a person has had their hand crushed trying to remove old shock absorbers or install new ones. Also, a lot of people climb under their car and get into this repair only to realize that they can’t tell a shock absorber from a strut. Remember that caution should always be exercised when a repair on a car involves jacking the vehicle up and crawling underneath it. The cost to have new shock absorbers installed at a garage is typically about $750, including taxes and labor. That is money well spent.

7. Windshield Repairs

The television commercials make it look so easy. You just squirt a little epoxy or other gunk into a chip or crack in your car’s windshield and it magically looks brand new again. Anyone can do that by themselves, right? Wrong. A cracked or chipped windshield is a serious issue and safety hazard. People who experience a crack or chip in their windshield should get it fixed immediately and by a professional. And taking action quickly can save the windshield from needing to be replaced entirely, and save the owner big bucks. However, attempting to fix a chip or crack in a windshield oneself could make the crack or chip larger and require that a whole new windshield be installed. Sure, buying a can of stuff off the shelf at a hardware store and trying to fix a chipped or cracked windshield yourself will cost only about $10. But repairing a chip or crack in a windshield at a licensed garage costs only about $75, and you know it will be done properly. Replacing the entire windshield costs roughly $500. Do the math and take the appropriate action.


6. Engine Diagnostics

When the check engine light pops up on the dashboard of our car, it sends many of us into detective mode. Amateur sleuths love to try and figure out why the engine light has come on and what problem may be lurking under the hood. But a lot of damage can be done poking around under the hood of a car. And the reality is that unless you own very expensive automotive diagnostic equipment, the chances of you getting to the bottom of the mystery are slim at best. Truth is that the engine light could be on simply because your gas cap is not screwed on tight enough, or because your car is overheating and the engine is about to blow. The range of reasons is that large and dramatic. Best to get a mechanic to hook your car up to a diagnostic machine and source the problem for you. A diagnostic test on a car typically runs about $100 to $130.

5. Radiator

The radiator in your car falls into the category of “essential component.” Without the radiator, your car will overheat and this can lead to major engine malfunctions and expensive repair bills. The radiator is the heart of your car’s cooling system. When not working properly, you’re hooped. There are a ton of videos and blogs online that explain to people how they can replace the radiator in their car like the professionals in anywhere from 11 to 16 easy steps. Be careful. Replacing a car radiator is not as easy as the online community would like you to believe. The biggest problem encountered with these home repairs is that the hoses connecting the radiator to the engine are not secure enough and come loose, leading to significant problems. Also, if you screw up a radiator replacement it could cause your engine to blow, and a new engine costs between $5,000 and $7,000 in most cars today. Having a mechanic replace your radiator typically costs between $750 and $1,000. Not cheap. But cheaper than a new engine.

4. Fuel Pump

The fuel pump in your car supplies fuel at the correct pressure to the injector in the engine. This is an extremely sensitive and precise piece of equipment, and, as such, it is very expensive to repair or replace if it breaks. A newly installed fuel pump typically costs $1,500 to $2,000. With such a hefty price tag attached to it, it is not surprising that many people attempt to repair or replace the fuel pump in their car on their own. But getting this repair wrong can lead to a catastrophic failure in a vehicle and the car may need to be completely scraped. If you want to hold onto your car for a lot longer, it would be best to get a mechanic to do this repair or replacement. Keep in mind that a fuel pump can be kept in good condition simply by using quality fuel in the vehicle.

3. Brakes

To be fair, you can replace your own brakes. Many people have done this, and it is by no means the most complicated automotive repair on this list. That said, if you do replace the brakes on your car yourself, you had better get it right. Few safety problems with a vehicle are as dire as malfunctioning brakes. And keep in mind that a brake job does not just involve brake pads. It also involves calipers, rotors, wheel bearings and brake fluid. Get any one of these wrong and you could be putting yourself and the other occupants in your car in jeopardy. If you feel confident to undertake this job yourself, that’s fine. But for peace of mind alone, it might be best to have a professional change your brakes. In most areas, it costs about $500 to replace the brake pads and rotors in a vehicle. Not the most expensive repair, but one of the most important in terms of safety.

2. Head Gasket

A blown head gasket is as bad as it gets for most car owners. It can take 20 to 25 hours of labor for a qualified mechanic to replace a blown head gasket in a car. That’s half a week or more spent working on one head gasket. The cost for this repair can easily top $3,000. But the head gasket is critically important as it seals in the internal combustion process of a car engine, and keeps coolant and oil from mixing together as the two fluids travel from the engine block to the cylinder head. When a head gasket blows, you will not be able to operate your vehicle. Trying to fix this major repair on your own is never a good idea. If it takes a professionally trained mechanic half a week to tackle this problem, imagine how long it will take you in your home garage? Also, this is one of those repairs that, if you get it wrong, you could permanently damage your car’s engine. Be like most people and hope you never encounter this problem.


1. Transmission

The transmission is, arguably, the most complex part of a car. It is the Rubik’s Cube of most vehicles. Containing thousands of complex parts, a transmission serves a very important role to engage the car in forward drive or reverse. Owing to its complications, a transmission can almost never be repaired or replaced by the average backyard mechanic. Yet, many people try to repair the transmission themselves—usually with disastrous results. Even changing the transmission fluid in a car is complicated and a specialized procedure must be undertaken by a mechanic. Repairing a transmission can cost $2,000 to $3,000. While replacing the transmission costs anywhere from $4,500 to $6,000. But undertaking this complicated repair or replacement oneself is truly the Kamikaze mission of home auto repairs. Do yourself a favor and either take the car to a licensed garage for the repair or scrap your car altogether and get a new one.