4S shop said that if you spend 1 yuan more, you can change the oil cleaner. Is this tricky?

Recently, a friend left a message saying that when he went to change the oil in his car, the store recommended him to enjoy the VIP oil change method of pumping oil for an extra 1 yuan, so that all the sludge and residue in the oil pan can be pumped out and changed more cleanly. Would you like to ask if the effect of pumping oil is really that good? Will it be cheated?

just pump oil and add a VIP. This store is really a marketing genius! However, a VIP that can be made by adding 1 yuan is not of much value. Back to the topic, pumping oil can't be changed more cleanly, and it can't handle sludge and residue! In this issue, I will tell you about the tricks behind pumping oil!

how to pump oil?

the principle of pumping oil is very simple, that is, pumping the old oil from the oil pan with a pumping unit. The traditional method is to open the oil drain bolt on the oil pan and let the oil flow out by itself. Just like drinking a drink, pumping oil means drinking it through a straw, and putting oil means making a hole in the bottom of the bottle to flow out by itself.

of course, when pumping oil, it is impossible for technicians to pump oil with their mouths. You have to get a pumping unit, insert the vacuum tube of the pumping unit into the oil pan through the hole of the oil drain gauge, and then start the pumping unit to pump out the old oil in the oil pan. The operation process is extremely simple, and I really don't understand why it can be called VIP oil change method.

However, the method of pumping oil is not suitable for all models. A car without a traditional oil dipstick cannot pump oil, because there is no place to insert the vacuum tube. Now many models have cancelled the traditional oil dipstick and replaced it with electronic dipstick, such as BMW.

can residue and sludge really be removed?

Let's talk about the residue first

In fact, this matter can be understood after a little thought. The biggest function of the oil filter is to filter the residue, and the most residue left is the oil filter, not the oil pan. Replacing the oil filter element normally can avoid the situation of residue accumulation blocking the oil passage.

Let's talk about sludge.

I'm afraid you haven't seen what sludge in the oil pan looks like. The sludge in the oil pan is different from the sludge in the river, and it's all soft. The sludge accumulated in the oil pan is hardened like carbon deposit, and sprayed on it like paint, which may not be brushed off with a brush, let alone pumped off with a pumping unit.

There are two main reasons for sludge accumulation, the first is not changing the oil for a long time, and the second is using inferior engine oil. As long as these two points are avoided, there will basically be no sludge accumulation. Therefore, pumping the oil more thoroughly is just pulling eggs, which is no substantial difference from gravity oil change, and it is not worth 1 yuan. If the merchant does it for you for free, you can still use it.

is it recommended to pump oil just to make money?

Making more money is just one thing. There are also many shops that still use the method of pumping oil without spending money. As a car repairer, I deeply feel the reasons behind it.

Reduce labor intensity

The gravity oil change method needs to lift the car and drain the oil through the oil bottom bolt. At present, most models have engine lower guard plates, and it is a waste of time to remove the guard plates. In the aftermarket, where efficiency is king, it takes half an hour for others to maintain it, but you can't maintain it for an hour. Isn't that funny? Technicians naturally come as quickly as possible, and it is obviously much faster to pump oil without dismantling the guard plate and lifting the car.

avoid damage to accessories

frequent disassembly of the oil bottom bolt of the engine causes great wear, and improper operation may lead to over-threading, but it just won't bite tightly. The bolt overflowed and began to leak oil, which could not be stopped at all. We had to replace the bolt. If it is serious, the oil pan may need to be replaced. There are also some car oil pans that are plastic, and the oil drain bolts are also plastic, so the risk of being damaged is extremely high.

it was not broken before dismantling, but it was broken after dismantling. The responsibility must be the technician. Therefore, in order to avoid unnecessary troubles, many technicians simply don't move the oil pan screws.

In fact, pumping oil is more convenient and less labor-intensive than traditional draining oil, so some manufacturers are gradually applying the method of pumping oil to change oil. On the oil filler of many models, there is a reserved port for pumping oil separately.

what's with the oil blowing?

if the oil pump is VIP, then "blowing oil" is VVIP. "Blowing engine oil" is an upgraded version of pump oil. The price increase usually starts at around 1 yuan, and high-end brands can even ask for 2 yuan. Of course, some stores don't charge, but there are very few stores that don't charge. Shopkeepers usually say, "Blowing oil can blow out the residual oil in the internal pipeline of the engine, and the effect is the best! Don't believe you, when you add oil, you must add more than before! " This oil blower is a bit interesting. It has just started in recent years. Let's talk slowly.

"Blowing oil" means blowing high-pressure air into the engine lubrication system to blow out the old oil left in the pipeline. Specific operation requires a set of special equipment. ?

remove the oil filter, and then use a high-pressure air gun to blow air into the engine through the installation position of the oil filter. It's equivalent to blowing air into a beverage bottle with your mouth, and then blowing off the water droplets attached to the bottle wall. The principle is exactly the same ~?

how much oil will remain in the engine?

Actually, what the merchant said is true. There is still engine oil in the engine, which cannot be released by gravity method or pumping method, accounting for about 1%~15%. That is to say, the normal oil change amount of your car is 4L, so there is about .4L~.6L old oil that can't be released.

you can only blow out a small part of the oil that can't be released, and there are many that will never be blown out. For example, the oil in the oil radiator, variable timing adjusting wheel and other parts can't be taken out without disassembling it. So, blowing oil is just a gimmick, and it doesn't have much substantive effect like pumping oil. It is even more inappropriate to spend money on it.

In addition, there is no need to drain all the remaining engine oil, which is not necessary at all. Just gravity replacement is enough to meet the requirements. It is more valuable to improve the quality of engine oil than to spend money on letting it go.

there are also many people who say that high-pressure air contains a large amount of water, and blowing engine oil may lead to excessive water content in the engine lubrication system, which may easily lead to oil emulsification. In fact, this kind of worry is right, and there is such a risk in principle. This is directly related to the high-pressure air system in the maintenance workshop. Now many high-pressure systems have automatic dehumidification function, and the water content is already very small, which is difficult to cause oil emulsification. Of course, the equipment level of each store is different, and the question of emulsification depends on the actual situation. How to change the oil is the most suitable?

Gravity replacement after hot car

The most suitable oil change method is gravity replacement after hot car, which does not require oil pumping or oil blowing. What exactly is a hot car? It is the center line from the water temperature to the water thermometer, which is about 9℃. At this time, the oil has the best fluidity and can release more oil to the maximum extent.

as many people have said, when I go to change the oil, my car is always hot. It was a hot car when you went, but it was not necessarily a hot car when you changed the oil. If you catch up with the queue, it is not certain when you can maintain it. If it is winter, the oil temperature will drop about ten minutes after the flameout, and the fluidity will obviously deteriorate. Therefore, many excellent technicians put in the oil after the hot car in metropolis. Although the operation is a bit dangerous at this time, they may burn themselves, but there are really technicians changing the oil after the hot car.

in a word, pumping and blowing oil don't cost money, but they can be done without money, but most of them cost money. Small maintenance is only a few hundred dollars, and it really doesn't make sense to spend hundreds of dollars on this.