Buying a used car is always associated with a whole range of risks, in which a used engine is the most unpleasant and expensive. Unfortunately, most future car owners, first of all, are guided by the appearance of the car. The condition of the paintwork, traces of an accident and so on. These, of course, are also important factors. But, as real practice has proven, the first thing to think about when studying offers is how to check the car engine before buying.
What engine check is beneficial for the seller?
The most ideal option for a used car seller is when a potential buyer just looks under the hood and does not specifically check anything. Yes, perhaps he will pretend to be smart, and even ask a few questions, which, having veiled the truth, will not be difficult to answer. That's all.
The second step in incorrectly checking a car's engine before buying it is to try to evaluate its condition during a test drive. Nobody argues that this is a great way to see a hidden cat in a poke. No. But how is such a test usually performed? Right. A test drive is made in first or second gear. Carefully. No sudden pressure on the accelerator pedal. On a flat road without ups and downs.
Is it possible to somehow understand in this way whether a normal engine is sold to you along with the car? Of course, if the motor is killed in the trash - does not pull at all, "coughs", stalls - then even such a test will be enough. But this article is not about such cases. Moreover, they are extremely rare. Especially if you are not trying to buy a car at a ridiculous price for the market.
With "bare hands" it is impossible to fully check the engine
Going to used car shows with only money is the most common mistake. By eye, of course, much can also be determined and understood. But not all. Therefore, never hesitate to take at least a minimal arsenal to a meeting with the seller.
Here is the list:
- Rags, napkins or paper towels. Preferably white. It will become clear why later.
- Screwdriver universal. Or two - "minus" and "plus".
- Wrench for removing spark plugs. Naturally, if you are aiming for a diesel engine, this tool is not needed.
- Several running wrenches. Especially at 10, 12, 13, 14 and 17. They are not always useful. But when you need it, believe me, you will not find them in the trunk of a car for sale.
- This simple device is extremely often embarrassed to use, for fear of seeming too meticulous. Do not do like this. Why do you need a motor with a "leaky" piston?
- The cheapest one will do. Moreover, if you have a cool microprocessor-controlled device, it is better not to take this one. They tend to "think long". And we need a smart multimeter, which is any cheap Chinese one.
- This is perhaps one of the most important points. The fact is that for the majority, buying a car is an emotion, because of which you can completely forget everything that you knew.
So, here's another list for you. This is a cheat sheet, by printing or writing it in a notebook (smartphone), you will not forget on emotions how to check a car engine before buying:
- visual inspection;
- trial run;
- timing belt;
- spark plugs (if gasoline or gas);
- test in motion.
In principle, if you have an initial idea for each of the items presented in the cheat sheet, you can already go and look at the offers of sellers. If nothing, or almost nothing, is clear, below for each stage of checking a car engine before buying, short explanations are given.
So, the hood is open. Start with simple questions to the seller:
- What did they do with the motor in the recent past?
- What were the problems with the engine?
- Will it be necessary to invest in a motor?
By answering these questions, you can learn a lot of interesting things if you have a real car owner in front of you, and not a reseller. The latter, by the way, also does not hurt to "calculate". Overpaying a third party in our time is a norm that is not so difficult to get around.
There is practically no point in asking the current owner about such points as fuel consumption, engine cleanliness, care of operation and timeliness of the required maintenance. It is easy to answer such questions with lies, quickly invented right on the spot.
Now directly inspection of the engine. First, look for the presence of smudges of working fluids. Oil, antifreeze, brake fluid. If the engine is perfectly clean, and the odometer has more than 70 thousand mileage, it was 100% washed before sale. Before such a run, a clean engine is the norm, which, however, is not so easy to find in the secondary market. By the way, in 1 case out of 10, the motor that has passed more than one hundred thousand kilometers is clean simply because the owner is neat and loves his car.
Next, look for missing parts and traces of recent repairs. For example, if the car is relatively fresh, under the hood there simply cannot be fasteners of different colors and sloppy wire noodles. Wire instead of clamps, not insulated twists, the legendary blue electrical tape - all this is an excellent reason to once again ask what happened to the motor, and why it was corrected so crookedly.
The last, but very important stage, is the inspection of the power unit from below. Often it is skipped simply because there was no overpass, viewing hole or lift nearby. However, from below, in addition to smudges, you can see more terrible defects. For example, chips, cracks or deformations, which are not so difficult to “get” on our glorious roads. Do not spare the money - visit the nearest service station, and use the lift. At the same time, check the body and chassis.
Trial run and idling
Do not rush after an external examination to check the candles, compression and everything else. It is possible that these steps will not be necessary. First, you should look, or rather, listen to how the engine starts and how it idles. Leave the launch to the owner or assistant, if you have one.
While remaining at the open hood, go through this list:
- How did he manage to start the engine? Did it spin sluggishly, tightly, with jerks and gnashing, or cheerfully and without extraneous sounds?
- Launch attempts. Did it start the first time, or did you have to try two or three times? A serviceable engine, regardless of whether it is warmed up or not, should start on one try.
- Turnover after start. Even if the engine was warm before starting, in the first seconds it should work at high speeds. If not, then get ready for problems with the power system.
- Turnovers should be stable, not floating. It is clear that a serviceable motor cannot stall for no reason either.
When you're done with the motor, walk around the car and look at what's coming out of the exhaust pipe. Only light white vapor is allowed (this is not smoke), or an absolutely transparent exhaust. Gray, blue or black smoke are problems that require investment.
While the engine is running, you can check the generator in just one minute. Just for this you took a multimeter with you. Turn it into voltage measurement mode, and connect the probes to the battery terminals.
Here is the diagnostic checklist:
- With the engine running and consumers off, the voltage at the battery terminals should be between 14.3-14.8 volts. Even at idle.
- The ideal voltage in this position is 14.4 volts.
- When consumers are turned on (light, stove, air conditioner), the voltage in the on-board network will drop. If it falls below 13.8 volts, then this is a bad sign.
- When re-checking, but not at idle, but at a speed of 2500-3000 per minute, the indicators should not differ too much.
There is a myth that at idle the alternator does not have to cope, and the voltage will always be lower than at higher speeds. This is a 100% myth, nothing more. You should not be led if the seller convinces otherwise.
Engine oil, contrary to a common mistake, is checked in two places at once. The first is traditional. Oil dipstick. It needs to be pulled out, assessed by the level of risks, and also checked for the presence of third-party impurities. For this, you took rags, napkins or white paper towels with you to the bride. Wiping the dipstick on them, on a white background you can clearly see what condition the engine oil is. Ideally, it should be honey-colored, and there should be no traces on the napkin.
The second place to check, which few people think about, is the filler neck. Open the plug and look at it. If there is an incomprehensible black slurry on it, similar to dirty grease, or foam, the motor was clearly not spared. As a rule, this often happens when the car is not taken care of before selling, and is operated "at full steam". Actually, look into the neck too. On many engines, parts of the gas distribution mechanism are visible through it. If they are in soot or grease - trouble.
Elementary check the level of antifreeze, as well as its condition. To do this, simply unscrew the cap of the expansion tank. Inside there should be no foam, sediment or obviously foreign powder (this is a sealant). The color of the coolant will tell you a lot about how old it is. As a rule, this working fluid is not changed in a timely manner, because it has a dirty color and a cloudy consistency.
The simplest, but extremely important point. Checked both visually and tactilely. The belt must be free of cracks, breaks and other defects. It is also important to make sure that it is sufficiently taut, does not sag or slip. Very often, unfortunately, the timely replacement of this part is neglected, waiting for the belt to break from old age.
Spark plugs and compression
It makes no sense to describe in detail how to determine the state of an internal combustion engine by candles. You can remember only one thing - if the electrodes on the candles are without soot, not wet, and resemble a brick in color - order. It is important to inspect all the candles, since even one defective one is enough to understand that the motor will work anyhow.
Since the candles are turned out, check the compression at the same time. How to do this is written in the manual for any compression gauge. If this information is not available in your case, here is a short algorithm:
- Install a compression tester in the spark plug hole and press firmly to seal.
- Have a helper or owner turn the starter.
- Take instrument readings.
To understand if the compression is normal in front of you, it is recommended to find the values for a specific engine model in advance. Naturally, if the compression is, for example, 6 units, then no hints are needed. The engine is dead.
Test in motion
Only after all of the above, you can finally proceed to the test run. Here are a few tips that are highly recommended at this stage:
- See how the car starts and accelerates in first gear.
- Feel free to test this moment not only in a calm mode, but also in a slightly aggressive one. Nothing bad will happen to the motor in a few seconds of sharp acceleration.
- Check the operation of the engine in all gears by driving to the track. A test run on a viewing platform or a narrow alley with a bad road is a bad idea.
- If possible, check how the engine handles uphill.
- After driving in different modes, pay attention to how the engine works after that at idle. Haven't the speed started to float and so on.
Do not forget about the most important thing - you may have to drive this car in the future. Therefore, the way she rides should not remain in the background. You should like how the car behaves in motion.
Engine check stage
Where to look
Traces of repair
Battery terminal voltage
With and without load
The presence of foreign impurities
Candles and compression
Idle after exercise
VIDEO: how to check a used car before buying
As you can see, just checking the car's engine before buying can turn into a whole epic. Not to mention the body and other details. However, the motor is called the heart of the car for a reason. Therefore, his “health” should always be in the foreground. If you buy a car only by external signs, then you may not get home on the purchase. Unfortunately, life examples of such an outcome are full.