This cheap detail can kill the engine!

We checked 10 expansion tank caps installed on all VAZ cars except Vesta, XRAY, Largus and “classics”. Samples were purchased all over Russia using a remote order.

Triune task

The expansion vessel plug prevents the liquid from splashing up and becoming contaminated. It also maintains an increased pressure in the system when the fluid expands due to heating. And the plug, when the system cools, must allow air to enter the expansion tank, so as not to create a vacuum, which leads to compression of the hoses.

An ordinary plug would handle the first task, but two valves serve to maintain high pressure and prevent vacuum. The exhaust valve controls the overpressure in the system and should open at 1.1 bar. The inlet valve opens when the pressure in the system falls 0.03-0.13 bar below atmospheric pressure.

Plug elements: 1 – valve holder; 2 – inlet valve; 3 – spring inlet valve; 4 – exhaust valve seal; 5 – exhaust valve; 6 – exhaust valve spring; 7 – body wrap; 8 – cover body.

Plug elements: 1 – valve holder; 2 – inlet valve; 3 – spring inlet valve; 4 – exhaust valve seal; 5 – exhaust valve; 6 – exhaust valve spring; 7 – body wrap; 8 – cover body.

Methodology

All plugs were checked for compliance with geometric dimensions by screwing them onto the threaded neck of a standard expansion vessel used on VAZ vehicles. Then the values ​​of pressure and vacuum were measured, with the exhaust and inlet valves working.

Thereafter, the samples were subjected to “drying”. We call this placing lids in a thermal chamber at 125°C for 24 hours. After that, the covers withstood the entire test cycle again.

This cheap detail can kill the engine!Checking the outlet valve opening pressure on the stand. The pressure in the tank is more than 2 bar, but the cork does not open. SchA will explode!

Checking the outlet valve opening pressure on the stand. The pressure in the tank is more than 2 bar, but the cork does not open. SchA will explode!

Members

This cheap detail can kill the engine!AROKI 332080, Dimitrovgrad

AROKI 332080, Dimitrovgrad

estimated price 130
The cork does not hold any pressure at all, which is why the motor can boil under a light load. Total failure.

This cheap detail can kill the engine!Auto Tech AT 1065-001 CR

Auto Tech AT 1065-001 CR

estimated price 260
Initially, the cork gave satisfactory results in terms of pressure, but after drying it lost the correct geometric dimensions and no longer wrapped around the neck of the tank. failed.

This cheap detail can kill the engine!AVTOVAZ 2108-1311065-004

AVTOVAZ 2108-1311065-004

estimated price 110
The cork withstood the pressure parameters until drying, and after heating, the pressure relief valve began to stick periodically. You can buy if there are no others.

This cheap detail can kill the engine!Automatic device 2108-1311065-01

Automatic device 2108-1311065-01

estimated price 280
The plug is absolutely thermally stable, but does not maintain sufficient pressure in the system. This can cause the engine to boil under load. Cork for the winter? Better to avoid.

This cheap detail can kill the engine!Pramo 21080, China

Pramo 21080, China

estimated price 190
It maintains an overpressure in the system of only 0.3 bar, which is unacceptable for modern engines and loads. Not apply!

This cheap detail can kill the engine!HPA 2108–1311065

HPA 2108–1311065

estimated price 200
This cork won’t do any damage other than the money spent on the purchase. It couldn’t even be screwed onto the neck of the tank. Total failure.

This cheap detail can kill the engine!ED Eurodetal, Rostov-on-Don

ED Eurodetal, Rostov-on-Don

estimated price 180
The plug can withstand an overpressure of only 0.1 bar. Engine boiling is inevitable. Do not buy!

This cheap detail can kill the engine!Ganz GRF 10001, China

Ganz GRF 10001, China

estimated price 250
It seems that they have decided to make the cork absolutely hermetic. It withstood an overpressure of more than 2 bar. Will the cooling system hold up? But after drying, the cork stopped wrapping around the neck of the tank. Total failure.

This cheap detail can kill the engine!Unnamed

Unnamed

estimated price 190
The cork ensures free communication of the tank with the atmosphere. Such a product makes no sense. Do not buy!

This cheap detail can kill the engine!luzar

luzar

estimated price 230
The cork withstood the factory requirements with minor flaws in the “raw” state and returned to normal after drying. You can take!

The test results relate only to a specific sample of products and cannot serve as a basis for judgments on all products with the same name as a whole.

Results

It was no accident that our reader sounded the alarm: to buy the simplest, it seems, detail is really an issue. Of the dozens of covers we tested, only two can be put on cars, and even those aren’t ideal. A simple device, no microprocessors or advanced technology for you – what is the problem in ensuring quality?

This cheap detail can kill the engine!Alexey Khomyakov, Test Engineer, NPO Talis LLC

Alexey Khomyakov, Test Engineer, NPO Talis LLC

SPECIALIST’S COMMENTS

– Recently, when testing various auto parts, we get more and more frightening results: the quality of spare parts is rapidly deteriorating! More than half of the presented samples of expansion vessel caps perform the function of plugs, and no pressure is released at all, even if its value exceeds 2 bar.

Why do we cook?


The operating temperature of engines increases over the years – this is required by the tendency to increase efficiency. The operating temperature of the electric fan on the first injection VAZs was 99 ° C, and on later models it grew to 105 ° C. This is a consequence of environmental regulations – many foreign cars have even higher temperatures.

In this case, the specified temperature is measured where the sensor is located. And in some places the coolant heats up even more. Increase the pressure in the cooling system to prevent it from boiling.

Modern antifreezes boil under atmospheric pressure at temperatures around 108°C. And only by increasing the pressure in the system, it is increased to a minimum of 120-125°C. With a decrease in atmospheric pressure, for example, in the mountains, boiling begins earlier – especially during heavy engine operation: dragging, steep climbs, and so on.

  • Why modern engines are doomed to overheat is described here.
  • “Behind the wheel” can be read in Telegram.

Source: Z R

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