Features of repair and operation of Weichai engines

Bison with dragon heart

Andrey Filippov, photo of the author and manufacturer

What has happened under the cabs of MAZs during their production: “whistling” Tutais, rattling MMZs, “Supers” MAN and Mercedes-Benz. And this is not counting the various experimental Deutz, Cummins, etc. But from its very birth to the present day, YaMZ engines have been MAZ’s inseparable friends. The model range of “Yaroslavl” vehicles installed on MAZs has always remained diverse, and until recently it seemed that it would always be this way. But the times when “monopolism” in engines simultaneously meant “unification and maintainability” are gone...

Now a single third-party provider is rather synonymous with “dependency.” And in the current economic realities, no one can afford this, not even such a giant as MAZ. So it was quite logical for Minsk residents to search for an alternative supplier of the power plant, and ideally, to produce their own engine. Moreover, not just any kind, but competitive both in the CIS market and in more demanding countries. And the solution, traditionally for recent years, was found in China.

Motors of the Celestial Empire

The Weichai Power company, whose products the Minsk Automobile Plant has turned its attention to, needs no introduction. These motors are well known in Russia with all their pros and cons. Some people praise them, some criticize them, but the overall picture is that they are a good modern engine if it is maintained as it should be. By the way, there seem to be no issues with the service either - Weichai is simple and repairable.

The line that MAZ currently installs on its trucks consists of three families.

The first is WP7. Two 7.5-liter engines, WP7.270E51 and WP7.300E51 with 271 and 299 hp. Accordingly, they are installed on trucks for regional transportation, as well as on various chassis for municipal vehicles.

The promising WP7.270E61 and WP7.300E61 also belong to this family. A special feature of these engines is their compliance with Euro 6 environmental standards. A reasonable foundation for the future.

The WP10 family is a 375-horsepower 9.7-liter in-line six WP10.375E53, relevant for the Kolos family: dump trucks, truck cranes, etc. technique.

The flagship family in the current model range is the WP12. It is the WP12.430E50 motor that is designed for installation on equipment from the Prostor family. Displacement – ​​11,596 cm3, power – 430 hp, torque – 2060 Nm.

On all engines, the achievement of Euro 5 is due to the use of urea, so tanks with a blue cap will now become an integral part of MAZ vehicles. This choice is quite understandable - the thermal stress, and therefore the service life of an engine with an SCR system is significantly higher than with EGR technology. And bench tests of the two technologies showed noticeable efficiency of the engine with the SCR system.

The 280-horsepower WP10NG280E51 deserves special mention. This is still the same in-line “six” of the WP10 family, only designed to run on natural gas (methane). It is this that Minsk residents, along with Cummins and YaMZ, are currently actively testing as part of developments on gas issues.

In addition, active work is underway on the “compact” WP4 family. It will be represented by an inline four WP4.1NQ190E50 of Euro 5 environmental class. The 190-horsepower engine with a displacement of 4100 cm3 is perfect for the Cornet family of medium-duty vehicles. Taking into account the growing demand for equipment with a gross weight of up to 12,000 kg, this is, as they say, “a bast in a row.”

In principle, until recently MAZ also offered the WP12.430E40 engine of the Euro 4 environmental class, but with the advent of Euro 5 in Russia, it was considered unpromising, and has now been replaced by the aforementioned analogue WP12.430E50.
Technical characteristics of Weichai engines

Repair procedure

Before starting work, it is important to follow the procedure in order to achieve good results, which is called “do no harm.” Here's what you need to do:

1. battery disconnection;
2. washing the engine and the area around it;
3. marking electrical wires (if necessary);
4. blocking holes from foreign objects;
5. decrease in pressure (before disconnecting the fuel system).

It is very important to remove from the surfaces of parts all the products that were applied before the repair. Parts containing threads must be cleaned with a brush.

Since the engine is, without exaggeration, the heart of technology, it is very important to comply with all the requirements given in the instructions for it, and not neglect contacting professionals.

There are no secondary elements in special equipment, at the same time the engine is the main one. If you care for it properly (check the oil pressure indicators, temperature indicators and all measuring instruments) and do not ignore the signals it gives, then it will last the period allotted by the manufacturer, or even longer.

Credit of trust

One of the bonuses for those who purchased a truck with a Weichai engine, strange as it may sound, is the interest in promising engines on the part of MAZ itself. Representatives of the plant try to track the operation of each vehicle with the “heart of a dragon”, sending surveys to carriers to establish clear feedback. Moreover, there are two questionnaires: one for the driver, one for the mechanic. And each one has the right questions, taking into account the nuances of perception from different sides: from the cockpit or from the viewing hole.

I was allowed to take a sneak peek at the survey results, with the condition that I not disclose details. In fact, for once, Minsk residents are simply playing it safe – the reviews were mostly positive. Operators note the good traction properties of the engines, low noise levels from the Weichai engine and low fuel consumption. Moreover, some have already expressed a desire to replenish their MAZ fleet with Chinese engines.

However, it should be taken into account that we are talking about MAZ-643029, MAZ-544029 truck tractors and MAZ-650129 dump trucks with Euro 4 engines, which are no longer installed on equipment coming off the assembly line. But there are no reviews on the current Euro 5 yet, so make allowances for everything that was said earlier.

The only drawback voiced by carriers is the poor preparation of local service departments for the arrival of a new engine. The result is longer service times and the need for pre-registration. At MAZ they are aware of this problem and are now actively retraining service station specialists to work with Weichai engines. In addition, during the period of adaptation to new power plants, it is practiced to create mobile teams with diagnostic instruments in order to eliminate identified deficiencies at the carrier’s base, saving his time. The approach is modern, let's see how it works in real life.

Prevention of breakdowns

Repair of Weichai diesel engines can be prevented by:

• timely checking of the fuel system;
• regulation of the brake mechanism;
• regulation of thermal clearances of valves.

The design and operation features of Weichai engines make it necessary to regularly check and replace air filters to prevent turbocharger failure.

It is also important to timely replace fuel filters, and, if possible, install an additional SEPAR filter (to extend the performance of the fuel system to the maximum period).

Regular checks will also greatly benefit the engine:

• oil level and pressure. If the level is below or above the dipstick scale, the diesel engine must not be started. Moreover, the difference on the dipstick between the upper and lower marks is three liters;
• coolant level (if it is not enough, you need to add it to the required level). Remember to release the pressure before this procedure to avoid burns from the hot liquid;
• fuel level;
• presence of leaks;
• scratches and cracks on the V-belt. A scratched or deformed belt should be replaced;
• the quality of fan operation (if it is plastic, then its geometry should not be damaged, if it is metal, then its rivets and blades should be in their original condition), fastening of elements, battery charging indicator;
• engine speed (they should increase smoothly).

Starting at low temperatures (for example, minus 250C) should be done using auxiliary means (heating flanges activated via a relay).

Weichai – bet on…

However, Weichai supplies from China are a temporary phenomenon. Last September, in the Great Stone industrial park, the Minsk Automobile Plant, together with the Chinese company Weichai Power, began construction of an engine production plant. Guess who will be the main consumer of the product if the company is called MAZ-Weichai LLC?

In preliminary plans, it was announced that the line of “Belarusian” Weichai engines will consist of four families: WP5 (160–220 hp) of the Euro 5 environmental class, WP7 (210–300 hp), WP12 (270–340 hp) and WP13 (353–405 hp) of the Euro 6 environmental class. Moreover, judging by the presentations, the main focus is on the WP12/WP13 engines, as the most promising.

Initially, all components for the production of engines will come from China. The inevitable localization process will begin with machining attachments and accessories.

The plant's design capacity is up to 20,000 motors per year. However, initially the enterprise will operate in one shift and only after reaching an annual output of 10,000 units will it switch to two-shift operation, reaching maximum productivity.

According to the plan, construction will be completed at the end of 2022 - beginning of 2019, at which time serial production of engines will begin. Not long to wait...

Demand for MAZs with Weichai Power engines is growing. The first Euro-5 trucks were shipped

Perhaps for some, the decision of the Minsk Automobile Plant to begin building a strategic partnership with Weichai Power came as a surprise, but in fact, mutual interest between the Belarusian automaker and Chinese engine manufacturers arose ten years ago and has only intensified since then. Some time ago, a project was being worked out for the development and production of a heavy diesel engine in Belarus at the Minsk Motor Plant site - MAZ was supposed to become the main consumer. But in the end, it was decided to build a new plant on shares with MAZ itself - its foundation in the Great Stone industrial park took place in September last year.

The MAZ-Weichai joint venture will produce diesel engines for trucks, special vehicles and buses. It is planned to completely assemble (CKD) engines of models WP4, WP5, WP7 and WP12 of the Euro-5 and Euro-6 environmental standards. Their power ranges from 170 to 460 hp. The motors are reliable: the declared service life is at least 1 million km, depending on operating conditions. The design capacity will be up to 20 thousand engines per year. At first, the enterprise will operate in one shift, and when it reaches the annual volume of 10 thousand units, it will switch to a two-shift operating mode.

The MAZ-643029-1420-012 (6x4) truck tractor with a Weichei Power WP12.430 engine (Euro-4) has a reinforced rear suspension (permissible load - 26,000 kg), a powerful SSU (load - 22,500 kg) and is designed to work as a part of road trains with a gross weight of 65,000 kg

Nevertheless, serial trucks with Weichai engines are already being produced on the assembly line of the Minsk Automobile Plant - the engines for them are still supplied from China. MAZ has developed a whole line of trucks with WP12 diesel engines (in-line six with a displacement of 11.6 liters): it includes truck tractors (4x2, 6x4) and dump trucks (6x4). Automobile chassis with 4x2 and 6x4 wheel arrangement, 4x2 and 6x4 dump trucks have been developed with WP7 engines (in-line six with a displacement of 7.14 liters).

Road cleaning machine KO-806B-20 on a MAZ-534023 chassis with a Weichai Power WP10NG gas engine (280 hp, Euro-5). The total filling volume of compressed natural gas cylinders is 1128 liters, which provides a range of about 500 km

The comfortable mobile office "MAZ-Kupava" uses the MAZ-631223 chassis (6x2) with Weichai Power WP10NG (280 hp, Euro-5). The total filling volume of compressed methane cylinders is 700 liters, which provides a power reserve of about 300 km

In addition, the line of trucks of the Minsk Automobile Plant also includes vehicles with a WP10NG280 engine (power 280 hp) running on natural gas - methane (modifications are possible using only compressed or only liquefied gas, as well as combined versions of CNG + LNG).

Flatbed truck MAZ-534023-520-013P1 with a Weichai Power WP10NG280E50 gas engine and combined CNG+LNG power supply. The gas fuel reserve is enough to travel about 600 km at one filling station

From the beginning of 2022, MAZ trucks with Euro-4 Weichai Power engines began to actively promote themselves in the domestic and foreign markets: for such vehicles the warranty period was significantly increased (up to 24 months or 200 thousand kilometers for tractors; up to 24 months or 100 thousand kilometers for dump trucks) and the service interval has been increased (from 30 thousand to 60 thousand kilometers for tractors and up to 40 thousand kilometers for dump trucks). In addition, owners of MAZ vehicles with an installed engine from Weichai Power in Russia are additionally given the opportunity to have their power unit serviced free of charge when undergoing maintenance-2 and maintenance-3.

MAZ vehicles with WP12 engines found their first buyers in the domestic market last year. The purchased equipment included MAZ-544029 and MAZ-643029 truck tractors and MAZ-650129 dump trucks. According to reviews from operating companies and organizations, trucks with Chinese “hearts” operate flawlessly. Drivers are also satisfied with both cars and engines.

MAZ-650129 dump truck with a 20 cc platform. The car is equipped with a Weichai Power WP12.430E40 (Euro-4) engine. The power of this power unit is 430 hp; maximum torque - 2060 Nm

As for organizing service for cars with Chinese engines, work in this direction has been going on since 2015, when Weichai engines began to be installed en masse on MAZ trucks. And today, in addition to Minsk trucks with Weichai engines, 44 authorized partners (service stations) in Belarus, about 100 in Russia, and 17 in Ukraine are already ready to serve. Specialists from service organizations have undergone appropriate training and are ready to provide service support for the equipment.

It should be noted that in February of this year, the Minsk Automobile Plant launched a free service program for Weichai engines in the Republic of Belarus when undergoing TO-1 and TO-2. The essence of this program is that owners of MAZ vehicles with an installed Weichai Power engine have the opportunity to receive additional free engine maintenance when undergoing Maintenance 1 and 2, and are also provided with an extended engine warranty of up to 3 years. To undergo free maintenance, you must contact an authorized MAZ service station in the region to register your vehicle under warranty, and also observe the frequency of maintenance.

MAZ-544028 Prostor truck tractors will be equipped with Weichai Power WP12.430E50 engines (Euro 5) and ZF 16S2520TO gearboxes

Since the beginning of this year, the Minsk Automobile Plant has begun producing trucks with 430-horsepower WP12.430E50 engines meeting the Euro-5 environmental standard. Truck tractors MAZ-544028 (4x2) in two trim levels and MAZ-643028 (6x4) in four trim levels (both with reinforced suspension and with hydraulic take-off) are already available for order. The popular MAZ-650128 (6x4) dump truck with rear unloading is offered in 18 trim levels. They differ in: types (U-shaped or U-shaped) and volumes (12.5/15.4/19/20 m3) of platforms; using two different models of gearboxes (ZF 16S2520TO or Fast Gear 12JS200TA); two types of cabins (small restyled type 6501 or large restyled with a low roof type 5440).

As reported by the press service of MAZ OJSC, sales of trucks with Weichai Power engines by year amounted to: 2015-2016 - 30 units; 2022 - 182 units. At the same time, 90 percent of the trucks from this quantity were shipped to Russia, the rest were purchased by Belarusian companies. Since the beginning of this year, 152 MAZ trucks equipped with Weichai engines have already been sold.

Weichai Diesel Engine Catalog