Buying a used car: how to check the engine

The motor consists of a huge number of rubbing and moving of elements, while experiencing high load. To know the condition of the engine is visually very difficult — defects may not display any signs. But you can reduce the risk of erroneous purchase, looking at key points, writes AutoNews.

Open the hood

As a true psychological techniques you can open the hood of the car and inquiring to look at the seller, immersed in meaningful silence. A decent owner will not stand and he will tell you what and how was done under the hood lately.

You should also Unscrew the oil plug and look at its back — no white marks and emulsions shouldn’t be here. If they are – then, the engine has overheated (and repeatedly), the cylinder block jarred the gasket broke, antifreeze got into the oil. This engine a long time without major repairs will not live.

This plaque on the back of the tube to the inevitable repairs — the engine was overheated, and the oil mixed with coolant

You also need to pay attention to appearance podrabotki. If the key units are covered with decorative plastic covers, they are better off keep it either snaps or a couple-three bolts. Reclaimed or whether the engine has a natural patina of dust? Better if it was just a dirty motor. Such a motor is easy to find traces of the leak, zamylivanie or recent repair. Options grated to Shine the units must be alerted. Either the owner really fanatical sissy, or trying to hide any faults.


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But drips oil is not a sentence (some of the motors starting to get sick with such ailments almost from the second or third year of life), although it was the first occasion for bargaining. Another thing is, when oil or antifreeze drips from the car. In this case, it smacks of urgent repair with the replacement of a large number of items. The lack of antifreeze and engine oil — a popular cause of death of the motor.

Under the setting of hiding the true condition of the motor

Black color oil on the dipstick and the low level of antifreeze in the system – not an indicator of the demise of the engine, but an occasion to reflect on the attitude of the owner of the car, require a service book and keep track of replacement intervals consumables. Most often, negligent drivers does not prove it. In this case, it is recommended not to trust the seller’s word for it and check it out myself or in the service.

It is difficult to adequately assess the condition of the motor without lifting the car and looking at the oil pan. This is the closest to earth part of the engine and often suffer from the negligence of the driver or road services. Welded or plastered with sealant cracks on the pallet is not uncommon. A new part is expensive, changes (especially for front – and all-wheel drive car) is difficult, and the attack, if it came in a pallet may have passed on other details. And if it was “exit wound”, then most likely the motor had to work to dry until the driver discovered the leak.

Also need to touch the drive belts: not much they SAG when pressed, there are no visible cracks? If they start lohmataya or have visible creases that need urgent replacement. Consideration should be given to and the timing belt, especially if it can be viewed without removing the protective caps. His replacement is an expensive operation.

In many engines it is possible to visually assess the condition of the supports — pillows engine. If the rubber is cracked and tears — be prepared to part with a round sum or to put up with the vibrations of the body. If the engine is turbocharged, you need to check the turbocharger and an additional intercooler radiator on the subject of oiling and leaks.

You should to evaluate the condition of the radiator and its pipes. Radiator problems can severely damage the experience of buying a car, especially in hot weather. Stains, traces of antifreeze damaged the honeycomb of the radiator itself, the curves of attachment is a reason to ask relevant questions the user, for example when he changed the radiator cap.

Start motor

Definitely need to see that “speak” the icons and writes the cluster with the engine running. The main indicator lamp — Check engine should go off a few seconds after switching on the ignition. If not, you will have to go to computer diagnostics.

Check engine control light is yellow or orange in the form of motor

The ideal time to check is when the engine is cold. During warm-up, the loudest we can hear all other sounds, the engine shows all the problems. As the heating part of them disappears.

You need to pay attention and then, with a turnover of starter the engine starts. If long, then most likely the battery left a bit or have a problem with the starter, power supply system or sparking. The engine, even cold, have to wind up quickly.

When you start on cold it’s fine if the revs are higher than idle, but they should not float within wide limits, and the engine to choke or triple. Strong shaking has wound motor will indicate either slain the pillows of the engine or a problem with the power supply system and ignition. However, each motor has its own tolerances, vibrations and sounds. A universal standard does not exist. If in doubt, better to call in specialized service.


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During warm-up, no metal sounds or grinding noise from a motor should not be heard. Loud sound (or sound like a diesel, but a petrol motor) may signal problems with the expansion valve, the noise and whistling from the area of the hinged strap — on worn bearings, rollers, hollow sound from under the valve covers — that it is time to adjust the valves, metallic clank from under the timing cover may indicate the need to quickly pull the chain.

When the engine is warmed up, the revs should be close to idle and level off. If the rpm is noticeably swim, most likely, have to clean the throttle, also the problem may be in volumetric or candles. Try press accelerator: if the motor choked or started to troit, the same version, plus, perhaps, shoot through the high voltage ignition wires.

The smoke from the exhaust and the color

A lot about the health of the motor can tell the exhaust gases. Grey or bluish smoke from the chimney will talk about the need to replace the oil caps, which leads to drops of engine oil level in the system — it gets to the combustion chamber. And assuming a couple of significant oil starvation of the engine, you can get on kapitalku.

White smoke from the pipe to the replacement of the gaskets of the motor, which will cause the parse. The cylinders gets antifreeze or water is a sign that overhaul is not far off. Exception: smoke white in winter or in the first few minutes after engine start is considered the norm, as evidence of the presence of condensate in the exhaust system. On a warm engine in warm time of the year it should not be.

If warm outside, and pipe swirls of white smoke, the engine is expecting too much

Black smoke. Most likely, inside the engine has accumulated a large amount of soot or is there an obvious problem in the fuel system. However, this is not final cause. In this case it is better to abandon the purchase. The exception may be diesel engines, there may be a sour fuel high-pressure pump. But it is a very expensive part.

Norma — a little cloud of steam near the pipe and the drops of condensation on single or pale-grey smoke at high rpm.

While a working engine, you can assess the condition of the exhaust system roar, wheezing or backache say about issues ranging from the strips and ending with the rotten elements of the issue.

Electronic motor diagnostics

Much talk of electronic motor diagnostics, which can be produced as a dealer scanner or simple Chinese a Bluetooth device by connecting to the diagnostic socket OBD-II.

The most common fault is a failed catalyst and lambda probe in the exhaust system. And let whatever was saying “garage experts” on that machine and without them it rides like a bullet, the fuel consumption fell almost to zero, don’t fall for these stories, and guide the reasoned bargaining. Damaged or deleted, the catalyst can go sideways during the test to the toxicity of the exhaust. In addition, the ceramic inside of the catalyst can get into the engine, that sometimes happens to fresh cars. Known case with the Kia Rio, when the person on 100 000 km got to overhaul just the fault of the crumbling of the catalyst. Under warranty this issue not covered.

Another easily identifiable error — misfire on certain cylinders. Here are the options: spark plugs, coils, high voltage wires — all this costs money and requires immediate intervention.

Test drive

Under the loads the motor may demonstrate their best qualities and to discredit the condition of the car and reputation of the seller. The tandem motor-box is an important indicator of the appearance of the car and its condition. You need to pay attention to possible symptoms: tremors, jerks, vibration, smell in the cabin (oil, fuel, exhaust gases), ambient noise both at medium and high revs.

After the trip, it is necessary again to look under the hood. What would be licked to Shine the motor or not, “tired” seals or gasket will show itself.