Leaks

This car runs fine, but a close inspection revealed the coolant leak from the radiator. As a minimum, this car requires a new radiator, but sometimes, a cracked radiator may be a sign of more serious problems. It’s best to avoid used cars with this type of issues.

Watch out for oil leaks too. They may not be visible from above, but here is the trick – look underneath the car using your flashlight. Check the lower part of the engine and transmission. Everything has to be dry, like in this car. There might be a slight wetness which is not too bad, but there should be no leaks.

Low oil level

We checked the oil level in this car, and it’s very low. Oil looks dirty too. This means that either this engine consumes oil or it was very long since the last oil change was done. In addition, the engine wears faster when low on oil. Normally the oil level should be close to “Full” mark.

Engine oil in this car looks clean and the level is OK. It looks like the oil change has been done recently.

With the engine off, check under the oil cap

This test can tell a lot about the engine. If you aren’t comfortable doing this test, leave it to your mechanic. With the engine off, remove the oil filler cap and look under it.

For example, in the left photo, you can see there is a lot of black carbon deposits under the cap. The visible internal engine parts and the oil cap itself look very dirty too. Usually this is a sign of poor maintenance. In the right photo everything looks clean.

Watch out for performance mods

Be careful if a used car has some performance mods. If done right, the modifications can greatly improve the vehicle performance. However, poorly done engine mods can lead to many problems, especially if parts that were originally on the vehicle are no longer available. If the car has been modified, it’s also likely that it has been raced or otherwise abused.