By Anthony Santiago - Editor-in-Chief

September 5, 2022
what to check on a used car

What to Check on a Used Car

When buying a used car, you should always check the vehicle history report and try to see the car in person. The vehicle history report is the first step I always recommend once you are ready to seriously take a look at a vehicle. It's a small investment before you put thousands of dollars into your new car purchase.

However, what do you look for and what clues can be revealed on the Vehicle History Report? And how do you find out if the car has any major problems?

While the vehicle history report can give you an "idea" of the service and overall health of the car, It's not enough to just check the Carfax report, you will need to see the car in person and take a thorough test drive.

We will get into each of the areas to look at during your test drive.

Furthermore, there are many other factors that affect the value of a car. In this article, I'll go over everything you need to know about checking a car's condition before buying it.

I'll also cover what to look for when buying a used car online versus going to a dealership. This will help you make sure you get the best deal possible.

Unfortunately, there are some people who buy cars without checking the VIN number first. They assume that because the car looks new, it must be safe. This can potentially be a costly mistake but it's ALWAYS best to invest in a vehicle history report or else you might just end up with a lemon.

A word of caution, vehicle history reports are ONLY as good as the information that is reported to government agencies or insurance carriers. There are times when an accident or incident is not reported. That is why it is always good practice to get inspected or conduct a PPI with a reputable auto mechanic.

what to check on a used car

What to Look for When Inspecting a Used Car

A thorough inspection should include checking every part of the vehicle. This includes the interior, exterior, electrical and engine. While there are many areas to check, the main area to focus on is the engine and transmission as they are the most expensive to fix. The second most expensive area is electrical issues.

Here is a quick guide on are some things you should check:

Start up the Engine

Turn the key and listen for abnormal noises. You should hear nothing unusual. The engine should crank and turn over easily. However, if you do hear something, take note of what it sounds like.

  • Was it hard to start? This can be a symptom of a failing fuel pump, starter or low battery. If the car starts with jumper cables, it's most likely time to replace the battery.
  • It doesn't start or doesn't click? This can be a starter issue or a bigger issue of a hydro locked engine. The engine must try to crank or start. If not, I suggest looking elsewhere.

What Color is the Exhaust Smoke?

The exhaust smoke color of a vehicle depends on a few factors but it should be clear and not black, blue or white. If you see white colored exhaust, it could be the temperature and it is steam.

what to check on a used car - exhaust smoke color

No Color Smoke - Everything should be ok. If it smells like fuel then the car might be running rich. If it smells like sulfur or rotten eggs, you might have a clogged catalytic converter.

White Smoke - The white smoke should dissipate quickly and it should not smell sweet. If it smells sweet then you MIGHT have coolant in the engine, which is bad and might indicate a bad head gasket.

Blue Smoke - Blue smoke indicates that the car is burning oil. It might indicate a bad piston ring.

Black Smoke - Black smoke indicates that you are burning excessive fuel or running rich. This is common with diesel trucks who like are "rolling coal"

Check for Leaks

Older cars will commonly leak. However, if you are getting low coolant this can leak to catastrophic failure if you overheat the engine. Weeping or dripping is acceptable. You can use additives like Liqui Moly Motor Oil Saver to help slow the leaks. I have used this successfully in the past.

  • Are there a lot of stains under the car? Most commonly are oil leaks. Depending on the make and model of your car, it could be a valve cover gasket or oil pans. You can possibly smell oil burning on the engine if it's leaking on the manifold. This will show up as a "rainbow" effect on the floor or residual.
  • Do you smell any coolant leaks? Coolant leaks typically smell sweet. This is because coolant is treated with ethylene glycol. It also helps determine the type of leak you might experience. Again, coolant leaks can be due to failed o-rings or tired coolant hoses or radiator.

Check the Oil

One important area to check is the engine oil. When checking the oil levels, check the color of the oil inside the dipstick tube. Yellowish or brownish oil could indicate that the engine isn't taking in enough oil. This could cause damage to the engine and lead to expensive repairs.

A dirty dipstick indicates that you haven't checked the oil level in a while. If the oil level is very low, the engine will start running dry and stop working. You'll need to change the oil immediately.

Check the Dash Lights:

The car's dash lights can help determine the condition of the car. Most if not all cars today are controlled by an ECU and computer. The car monitors its sensors and will report back a dash light if any of them exceed the tolerances. If there are any dash lights, it's not a sign to run away, but to be aware of potential repairs in the future.

  1. Do you see a check engine light? Most likely this is an emissions issue. It could be as simple as a loose gas cap and simple as an ignition coil replacement. However, if the car drives smoothly then it is not a huge deal but would need to be addressed for an inspection sticker.
  2. Do you see a brake light? This indicates that this is a brake wear sensor. If you see an ABS light, then that could spell bigger troubles with an ABS pump failure. A PPI would help determine that.
  3. Do you see a coolant light? It could be as simple as a low coolant. But if there are leaks underneath the car, then you would need to factor in this costly repair during the negotiating process.
  4. Do you see a transmission or DCS light? This is the only light that would recommend you walk away from. Today's modern transmissions are sophisticated engineering feats. If you see a transmission light, you are in for a world of hurt. I would avoid cars with this issue since transmissions can cost easily $2,000 or more.

Check All Electrical Items

One area that takes a few minutes is to check ALL the electrical components. For example, I failed to check that the power mirror adjustments didn't work on the vehicle and missed that under negotiations. This repair is a few hundred dollars and I opted not to get it fixed.

But that was a lesson learned.

Here is a quick checklist of everything you need to check: 

  1. Windows: Roll each window up and down. Keep note on if are not working
  2. Wipers: Check to make sure the wiper motors are working and the wipers are in good shape.
  3. Radio: Check that the powers on and all speakers are working ok.
  4. Sunroof: Check if the sunroof opens up and closes smoothly.
  5. Power Seats: Adjust your power seats to check all the seat motors are working in both directions.
  6. Lights: Have an assistant check the headlights, blinkers, tail lights and brake lights are working.
  7. Power Mirrors: Again, check that all the power mirrors adjustments are working correctly
  8. AC / Heater: Turn on both the heater and the AC to check both are working ok.

Checking Interior for Any Weird Smells

Now, it’s time to take a peek inside the vehicle. Start with the glove compartment. Is everything locked? Are there any items missing? Take note of anything suspicious. Next, open the door panels and check the seats. Does the seat cover smell like smoke? Has the carpet changed color? Do the seats feel soft? These are just a few questions to ask yourself.

Your nose is a very good tool to help sniff out any potential issues. If you smell mold, then you have a water source somewhere that is causing that odor. If you smell cigarette smoke, read more about how to remove smells from your car while it covers smoke smell, it works great on all types of smells.

  • Are there any stains? A good detail can help remove a majority of the stains. A steam cleaner and degreaser work wonders in combination. Otherwise there are fabric paints that can help refresh your stained interior and cover up the stains effectively.
  • Are there any seat rips? This can be easily patched up with available vinyl patches on Amazon. We will have a review on how we did a repair.

Checking the Exterior of the Car

The exterior inspection is one of the biggest parts of purchasing a vehicle. If you are looking to buy a used car, it’s imperative that you know what you are getting into. You want to make sure that there aren’t hidden issues that could come up later on. Here are some tips to help you find out if the seller is hiding something.

Look for dents, scratches, rust, and damage to the paint. As long as the subframe is ok and there are no sharp edges to any body damage, you should not have any issues with state inspection for a clean titled car. Cosmetic work on the car is secondary to a fully functioning, inspected car.

  • Is there any rust on the wheel wells? Rust is a big issue if you don't address it. It can rot out frames and floor panels so you will need to keep an eye out for rust.
  • Does the paint match? Accidents happen and paint matching can be difficult especially for metallic paint. Just be aware that plastic bumpers and metal body panels often are mismatched from the factory.

Check the Tires:

Checking the condition of your vehicle's tires is an important area to take a look at on a used car. Tires play a vital role in keeping your car safe and running smoothly. Check your tread depth and see the condition of the tire wear.

what to check on a used car - tires

When the tread is worn down to 3/32 of a millimeter, the tire needs to be replaced.Tire treads should be deep enough to prevent hydroplaning during driving conditions. Hydroplaning occurs when water builds up under the tire due to excessive speed. Once the tire loses traction, it begins to slide along the road surface. As a result, the driver loses control over the vehicle.

Next, check the sidewall thickness. Sidewalls are the rubber strips that surround the tire. They protect the tire from cuts and punctures. If the sidewall is damaged, it could mean that the tire is unsafe to use.

  • Do the tires match? There should be a max of 2 tire brands on your car. If there are more, it might indicate that the owner of the car was on a budget and was replacing tires one at a time. While this is not a tell-tale sign of a bad owner, you will need to budget $300-$800 on a new set of tires in the near future.
  • Is there any dry rot or side wall damage? If you notice a bulge in the side wall, that tire will need to be replaced. Factor in any replacement tires in respect to the seller's asking price.

Odometer Reading: Low Mileage vs High Mileage

Is Low Miles a Guarantee for Trouble-free Ownership?

A lower mile count doesn't necessarily mean a good deal automatically. Low miles is definitely desirable but the history of the maintenance of the vehicle is more important and how it was used.

A commuter's car with 90% highway miles is sometimes better than a low mileage car that was driven locally only. Oil changes and servicing helps prolong the life of the engine. 

Sludge can build up over time if the car was not serviced regularly. This can happen to full synthetic as well. So check the condition of the oil and review the vehicle history report. 

I personally like lower mileage and a reasonable amount of miles per year. I also like to see regular servicing. As mentioned always, you should thoroughly check the maintenance records and history of a vehicle before buying one. 

Are High Miles Really that Bad?

If you can find a good deal on a high mileage car with detailed service records, then I would consider purchasing. However, this is only good for owners who like to wrench and DIY repairs. High mileage cars typically are priced lower due to the miles and likelihood that repairs may be needed in the future.

Anything with OVER 100k miles is considered high miles. Depending on the age of the car, I would consider cars that are 6-15 years old. If a car is under 5 years old and has over 100k miles, my determining factor would be a PPI report. 

Check the odometer reading against the mileage stated on the vehicle history report. 

Take It to Your Mechanic

If you're looking to buy a used car, I always recommend a PPI. A PPI is a pre-purchase inspection. I would advise if you are not 100% comfortable checking out a used car.

You will need to coordinate with the seller if you can conduct a PPI and that you will be covering the costs. The auto shop should be convenient for the seller and should not hinder their own schedule. 

what to check on a used car - PPI

If there are numerous buyers, you might be better off taking a friend or mechanic with you to check out the car.

If the condition of the car looks good, then you should take it on the road for a test drive. Read our article on how to test drive a car and find out in 10 minutes if it's worth buying.

More Articles Worth Checking Out:

As we conclude 2023 and approach the new year, it's always interesting to see what articles are closing out the year. Recently, an

Read More

If you are approaching your lease's end, you might ask yourself, "Should you buy a car after lease?"You know the buyout price

Read More

I know from first-hand experience how NOT to buy a car, despite the seller being a family friend. I will cover exactly

Read More

Is it worth buying a 10 year old car today? Short answer: YES!I have personally owned new, old, and really old cars. In

Read More

Anthony Santiago - Editor-in-Chief

About the author

I am a passionate car enthusiast who likes to help people save money and avoid headaches when it comes to cars. I believe that everyone can find the right car at the right price. I share my tips and experience so you can learn quickly and maximize your next SUV, truck or car purchase.

{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}

Get Your Free Guide:
Top 3 Rules to Buying a Car