Inspect These Before Purchasing a Used, Direct-Injection or Turbocharged Vehicle
One of your first priorities when buying a used car is to make sure it's worth the money you're paying. The best and quickest way to do this is to open the car hood and check the engine. Most modern, secondhand cars these days have direct-injection or turbocharged engines, and their health--or lack of it--is a good indication of the vehicle's performance on the road. Therefore, it's important that you thoroughly inspect it before buying the secondhand vehicle.
So before you decide to buy that used car, bring a mechanic with you and have them check these things out when you visit the seller:
Used cars that are still under their warranty period are valuable to owners because it saves them money on vehicle repairs. This, however, becomes "null and void" if the owner isn't doing his/her part in maintaining the vehicle. The best way to know this is to check the service records.
Make sure to inspect if the owner is up-to-date and consistent with the vehicle's maintenance routine--especially the spark plugs and oil changes. If there are a lot of missed ones there, then chances are you won't be able to use the warranty in case your engine goes bust.
Most direct-injection engines are prone to valve sludge deposit build-up. They're a nasty bunch and can cause havoc on your engine and significantly affect its performance. Have a mechanic check the car's fuel system to see if there are a lot of grime in the fuel system. If there's gunk in there, then chances are its engine's not in good shape.
The vehicle's computer system stores all the codes needed to make the vehicle's parts work. What's more, it also contains--and stores--most of the codes that indicate the problems it encountered before. And that includes engine problems.
Have a professional do a diagnostic scan of the car's computer system. This allows you to see if there are persistent engine troubles that the car is having. Too much of them means something's really wrong with the drivetrain.
Some car owners prefer to modify their vehicles to make them faster, and this can be through a software and a couple of tweaks on some of the car's components. Whatever the case, these modifications can cause premature stress and damage to the engine. It is for this reason why most dealers won't honor the warranty when they see these modifications in the car.
Cylinders and Intake Valves
Have a professional perform compression tests on the engine--particularly the cylinders and intake valves. They might be small, but their performance--such as proper sealing--is essential to the health of a car's engine. Improper open-and-closes of these parts can indicate whether there's excessive wear-and-tear to your car's engine or if there's a lot of gunk in it.