How to diagnose a used car in 3 minutes when buying, so that later it won’t be excruciatingly painful

To avoid buying a used car with a damaged engine, you need to be able to check it. You can determine that the engine has exhausted its resource in several ways in literally 2-3 minutes.

Checking crankcase pressure using the cover

If you unscrew the oil filler cap while the engine is running and place it on top, it should not be pushed out. If it rises, then this indicates a breakthrough of gases from the combustion chamber into the crankcase, which does not happen in a working engine. When the cap lies quietly, or is even slightly sucked in, this means that everything is in order with the piston.

Oil vapor check

After turning off the warm engine, you also need to open the oil filler cap and see what fumes come out of it. In a normal engine, a white oil mist rises from there without a burnt smell. Blue smoke with a burnt oil smell indicates wear.

In addition, you can look at the back of the lid. It should be in clean oil, not in carbon deposits.

Checking the dipstick

Be sure to pull out the dipstick and check the oil level.

You need to examine its color. It should be clear or amber, but not black. You can also rub a drop of oil between your fingers. The oil film must retain its sliding properties for a long time. Bad oil will become rough after just a few rubbings. If it is in this condition, then it is better not to buy the car.

Checking soot in the exhaust system

If you insert a finger, maybe wrapped in a handkerchief, into the outlet of the muffler and wipe the wall of the tube, it should remain almost clean. The presence of moisture due to the formation of condensation is normal, the main thing is that there is no soot in the form of loose carbon deposits and oil.

Watch the video