You decided - "deal!" - shaking hands, you're happy, the salesperson is happy. Finally, you got your new wheels.
Few weeks later you notice blue smoke when you're starting the car in the morning. Few months later you discover that there is no oil left in the engine and finally got your car towed to the garage. "The engine is gone - has to be rebuilt" they diagnose.
In fact it's quite common scenario.
Read few tips that may help you to discover potential problems. However, I recommend to have the used car properly inspected by a mechanic prior purchase.
• Things you should know when shopping for a used car
• Check oil level and condition
• Look for leaks
• Check visible internal engine parts
• Timing belt
• Check the smoke
• Engine noises
• Warning lights "check engine" etc.
• Test-driving the car
• Mechanical inspection
• Do's and Don'ts
Things you should know before going to check a used carWhen buying a used car, without a doubt, first check a car history records. Some cars may have been flooded - worthless to buy. Others were written off by insurance due to serious accident. Many cars have altered mileage and so on.
If looking at the used car you noted any problem with the engine (e.g.: major oil leak or strong noise) or any abnormal behavior don't let the salesperson to mislead you. They may tell you, for example, that the leak is "overflow from the recent oil change" or "the noise will disappear later by itself or something like this". Generally, such defects never disappear by itself. If you have hesitation, move on - there are so many cars available.
Ask for service records if they are available. Look for oil change intervals - was the oil changed regularly? May be driving a thousand miles over suggested oil change interval won't cause any significant damage, but three-four thousand miles over recommended oil change interval can cause serious problems in the future. Keep in mind, that modern engines, especially those with turbo charger are sensitive to the oil change interval.
How to check the oil
If you find the oil is completely black (although for the Diesel engine black oil is normal) and (or) the oil level is very low (left picture) - suspect excessive oil consumption and (or) lack of maintenance. In either case the engine will more likely to have problems in the future. Another sign of poor maintenance would be dark stains (carbon deposits) covering the oil dipstick along its length.
Well maintained engine will more likely to have cleaner oil and the proper oil level (right picture), although this doesn't necessarily mean that the engine is in good shape; the oil just could have been changed recently.
Look for leaksLook for possible oil leaks. If the engine looks very clean and shiny it doesn't mean it has no leaks. Probably it has been shampooed. Most of the dealers shampoo the engine before putting a used car for sale. But there is the trick - look underneath the vehicle using your flashlight. Check the lower part of the engine and transmission. Everything has to be dry. There might be slight wetness which is not that bad, but there should be no leaks. See any leaks? Oil drops on the parking space? This may indicate a problem. The water condensations dripping from the air conditioner drain tube is normal. The A/C drain tube is usually located on the passenger side of the firewall.
If it's possible, look at the internal parts through the oil filler neck
(Don't open the oil cap while the engine is
In either case, avoid buying such a car - sooner or later it will have serious engine problems.
Well maintained engine usually looks pretty clean inside; if you check few cars of the same model, it's easy to see the difference. However, again, if the engine looks clean inside it doesn't mean that it has no other possible problems - as a last step, have the vehicle inspected by a mechanic of your choice.
Timing beltMany cars, especially with four-cylinder engine, have a timing belt that needs to be replaced at a certain interval - usually between 60,000 and 100,000 miles (100,000 and 160,000 km). If it wasn't replaced by the previous owner, you will have to do that. It's difficult to check it on the car because the timing belt is protected by the protective covers. The only way is to ask the previous owner if they have a receipt. Sometimes though, dealers place the timing belt replacement sticker somewhere on the top of the engine (see the picture) that indicates the date and the mileage when the belt was replaced.
Check the smoke
Listen for noises when the engine is runningThere shouldn't be strong noises, coming from the engine under any condition with no matter is the engine cold or hot. By the way, knocking or tapping at a cold start is one of the indicator of poor maintenance. Knocking, tapping or rattling noises indicate excessive wear of internal engine parts. Whistling may be caused by loose belt. If the engine makes too much noises, avoid buying such a used car (however, Diesel engines are always more noisy, it's normal).
Look at the instrument panelThere should be no warning lights such as "low oil pressure", "low oil level", "overheating", "check engine" or "service engine soon" etc. on the instrument panel when the engine is running.
I receive lot of questions about "check engine" or "service engine soon" light. You may find the explanation what "check engine" means in the article Why my "check engine" light is on
If the car has "check engine" or any other warning light coming on while driving, have the proper diagnostic done before deciding to buy the car; in some cases the problem could be very costly to repair.
Test driveTry to test drive a car for as long as you can. Try to accelerate, decelerate, take it on the highway if it's possible. The more you drive, the more chances you discover possible problems. If it's your first car, try to test drive few different cars of the same model to have better idea. If you feel anything that may indicate possible engine problem (e.g. vibrations, stumbling, misfiring, delay during acceleration, rattling noise, smoke, rough idling, etc.) avoid buying such a car. If you have any hesitation about the way the car drives, shop around, there are plenty of used cars available. Sometimes a sales person may try to push you to buy a car today and now because "tomorrow I won't give you this price" or "I have the customer who will buy this car tomorrow" - Don't rush, take your time to think, the more you shop around, the more chances to find the right car for the right price.
Mechanical inspectionAs a last step prior buying a used car, have the vehicle inspected by an experienced mechanic of your choice.
Do's and Don'ts- Don't buy a car if you see a smoke from exhaust pipe - only the water steam and water condensate dripping from the tail pipe is OK.
- Don't buy a car if engine knocks or works too noisy.
- Don't buy high-mileage cars. I'd recommend to avoid cars with more than 145,000 - 150,000 miles (230,000 - 240,000km)
- Don't buy cars that have some engine problems even if it seems to be easy to repair
- Do hire someone knowledgeable to have a vehicle inspected before you buy it.