Opposite engines Subaru with six cylinders exist in 3 generations. Initially, such motors (2.7 and 3.3 liters) were used for coupes of the top models of this brand. However, since November 2000, power units of the EZ series appeared, which began to be equipped with the following cars: Legacy, Outback, Tribeca.
The presented mechanisms of the third generation were initially produced with a volume of 3.0 liters, but since 2008 the volume of the unit was increased to 3.6 liters. These motors were produced until 2019. Now instead of them a new turbocharged opposition unit is produced, which is reduced in size to 4 cylinders.
The basis of Subaru EZ series engines is a cylinder block that has an open cooling jacket. Each of them is equipped with four valves. The head of the block has two distributor shafts. The valve train has no hydrocompensator system. There are 2 roller single row chains to drive the timing.
Technical characteristics
| Characteristics | Value |
|---|---|
| Exact volume | 2999 cm³ |
| Power system | Injector |
| Power | 245 hp |
| Torque | 297 Nm |
| Cylinder block | Aluminum, H6 |
| Cylinder head | Aluminum, 24 valves |
| Cylinder diameter | 89.2 mm |
| Piston stroke | 80 mm |
| Compression ratio | 10.7 |
| Ingine features | DOHC, AVLS |
| Hydrocompensators | No |
| Transmission timing | Chain |
| Fasor regulator | AVCS |
| Turbocharger | No |
| Oil volume | 5.8 liters (5W-30 recommended) |
| Environmental class | Euro 4 |
| Example service life | 320,000 km |
| Engine weight | 170 kg |
Reliability level
The Japanese 6-cylinder EZ30 unit from Subaru has high power figures, so it is very appreciated by owners who prefer this manufacturer. However, in addition to this fat plus, there is a considerable number of minuses, which are expressed in expensive and not infrequent breakdowns. For example, the breakdown of the gasket on one of the cylinder heads (the cause of appearance – overheating). Below is detailed information about all the problems of this motor that arise in the process of its operation.
Gasoline pump
The gasoline pump of the submersible type has a limited service life. Breakdown of this unit is accompanied by a drop in pressure in the fuel system, which provokes an increase in the startup time of the EZ30 engine. There are also jerks when gaining speed. There are loud sounds (buzzing) at startup.
A working gasoline pump should produce the following fuel supply pressure:
- not less than 2.5 bar in normal operation;
- at least 3.0 bar when the throttle is open.
To protect the fuel pump, the manufacturer installs a fine fuel filter, which should be cleaned or replaced with a new one, according to the maintenance list requirements.
Fuel pressure regulator
Failure of the fuel pressure regulator is evidenced by a prolonged start of the power unit when the key is quickly turned to the “start” position. Accordingly, if you give time to the gasoline pump to increase the pressure in the system, pausing with the ignition on, there will be no problems when starting the engine.
The failure of the regulator causes a decrease in fuel pressure in the ramp after the ignition is turned off. Also manifested is a decrease in traction, there are failures in engine operation during gear shifting.
The injectors on this engine have a long service life and are not subject to failure. To maintain the factory characteristics of the engine, this node should be periodically cleaned.
Generator
The design of the alternator on the Subaru EZ30D engine requires periodic monitoring by the user. Lowering the level of charging voltage (11 V or less), signals the occurrence of malfunctions in this device. In most cases, to revive it is enough to replace the diode bridge, but often it is necessary to replace the entire product. Another malfunction is the wear of bearings, which is accompanied by an unpleasant creaking. To solve these problems in a complex, it is enough to purchase a used generator.
Pump hydraulic power steering
Quite often extraneous sounds under the hood of Subaru cars appear due to the breakdown of the power steering pump. In addition to howling and rumbling, there is foaming and squeezing out of the hydraulic power steering fluid.
Often there are leaks under the gasket sealing gaskets of the power steering pump. The shaft gland, the gasket under the sensor, the connector, the hose on the supply, the body of the device leaks. In these cases, it is necessary to replace all the sealing materials of this unit. A defective pump will require a complete replacement. In this case, a used analog will be suitable. Additionally, you can install a radiator for cooling the hydraulic fluid. Such devices were supplied for cars sold on the Japanese market.
Air conditioning unit
The compressor of the air conditioning unit on the car Subaru with a 3.0 engine gives its owner a lot of trouble. This is due to the rapid wear of component parts. For example:
the compressor clutch over time begins to slip, burns, which leads to the need for its replacement;
leakage occurs at the suction and discharge line connections;
RPM sensor (73190AE000) fails;
Select and purchase an air conditioner compressor for the Subaru engine can be found in the list of contract parts.
Attachments (belt rollers)
Belt rollers of the attachment belt of this model of power unit are equipped with bearings with a short life. Very often their critical wear starts to manifest itself at low ambient temperatures – an unpleasant whistling noise appears. If the problem is ignored, the bearing unit jams, which leads to the breakage of the compressor unit mounting bracket. Such a problem can be solved by buying a used bracket at an auto dismantler. In order to avoid unnecessary expenditures it is necessary to replace the belt rollers at the first signs of their wear (whistling).
Temperature Reduction System (Tubes)
The metal tubes of the cooling system are located under the lower part of the EZ30 opposition motor. Such a design decision leads to the fact that during the operation of the machine they get on them road reagents. As a result, corrosion occurs. After a certain period of time, coolant leaks appear in the places affected by rust. As a result, loss of antifreeze leads to overheating of the power unit. It is necessary to carefully monitor the condition of these elements, perform their timely replacement, without waiting for tragic consequences.
Camshaft position sensor
The camshaft position sensor (J005T23781) for the power unit Subaru EZ30D is prone to breakdowns. Its problems are signaled by the error P0340. Overheating of this sensor leads to a shutdown of the motor during acceleration, with subsequent failures in its operation when restarting. However, all the above problems pass when the temperature of the sensor comes to normal. They also do not occur at a measured driving pace.
Throttle flap
The presented node does not give the owner of the car, any problems during the entire life of the car. However, in order to exclude air inflow through worn gaskets (arising from prolonged use of the car), it is necessary to perform their scheduled replacement.
Inlet manifold and air suction
The intake manifold on EZ30R engines is made of plastic and has a passive design. It has no geometry change mechanism like its light alloy predecessor. Therefore, air suction is completely eliminated, unlike its predecessor.
Carter Gas Ventilation Valve
The VKG valve for the Subaru EZ30R engine has a simple design: a breather valve is used, which is locked with a ball. This device is located on the valve cover on the right side. Prolonged use of the car leads to clogging of the breather. The valve ceases to perform its functions, the ball can not close the inlet hole. Such a malfunction is manifested by losses of oil, which is literally sucked into the intake manifold. Also, the pressure of gases in the crankcase increases, causing oil leaks across all seals.
With prolonged use of the car, the crankcase gas ventilation valve is subject to periodic replacement. It is performed in a set of connecting tubes, thus it is possible to exclude air sucking.
Spark coils and spark plugs
The location of the ignition coils of Subaru engines assumes their rapid mechanical wear. These devices are installed in the lower part of the motor and do not have protection from dirt, reagents, water and snow falling on them. Therefore, the plastic housings of the coils quickly fall into disrepair: cracks and delaminations appear. Failure of the ignition coil leads to disconnection of the cylinder on which it is installed.
Most owners of Subaru cars do not even suspect how easy it is to replace the coils and spark plugs, considering this work quite labor-intensive and expensive. Therefore, they turn to the service only after the appearance of a specific malfunction. In fact, the Subaru opposition engine is designed in such a way as to make this procedure as easy as possible. Therefore, the replacement of spark plugs and coils is a budgetary procedure that should be performed within the time period strictly specified by the manufacturer.
Oil leaks
Oil leaks can appear at the location of the heat exchanger. Such an unpleasantness is due to the loss of the sealing rubber element. It is quite easy to eliminate this problem, as the heat exchanger is in an accessible place above the oil filter.
Rubber valve cover gaskets
EZ30D powertrain valve covers are mounted on rubber seals. Several gaskets are used for each cover: one for the entire perimeter and several separate products for each well where the spark plug is installed. With prolonged use of the car, these seals come into disrepair: they dry out, crack, harden. They practically cease to perform their direct functions, which leads to oil leaks. Access to valve covers is limited, so the replacement of rubber seals is not easy and quite troublesome.
The timing cover
The timing cover is secured by screws (of which there are just under 6 dozen). It has a protective function. It is not uncommon for oil leaks to occur under it, which can lead to significant oil loss. If such a problem occurs, you should immediately contact service specialists to replace the gasket.
Gas timing mechanism
To drive the timing mechanism of the EZ30 power unit in Subaru cars, single-row roller-type chains of 2 pieces are used. They must be replaced when the engine mileage reaches 200 thousand kilometers. By this period, the chains are strongly stretched and make unpleasant sounds (crunch, squeak) during operation. These spare parts (13143AA041 and 13143AA051) are replaced as a set. This includes the following units:
- tensioner – 2 pcs;
- guide – 7 pcs.
- easel – 7 pcs.
Premature replacement of timing chains is required in case of problems in the operation of their hydraulic tensioners (backlash in the rods, reduced pressure level under the rod).
Pompa
The pump of the EZ30 opposition engine is rotated by the timing chain. This device has a reliable design, but with high mileage comes into disrepair and requires replacement. The malfunction is manifested by coolant leakage, which is removed through a specially provided drain hole in the engine. If leaks are detected, you should contact a service center as soon as possible to replace the pump.
Phase Shifter Clutches
Inlet camshafts of Subaru motors with a volume of 3.0 are equipped with phase-shifting devices, which are controlled by electrohydraulic valves. The presented design, unlike the device of similar clutches on Subaru EJ engines, is completely reliable and does not cause trouble to the owner of the car. Clutches with EJ over time begin to leak. Such leaks are repaired by replacing a set of o-rings.
Valve height adjustment system
The latest generation of Subaru engines with a volume of 3.0 liter is equipped with a system that adjusts the height of the intake valves. This system is called AVLS. It is designed for two stages of valve opening. The essence of its work is the possibility of increasing the height of valve opening when the load increases. The system is reliable and does not cause any problems. For smooth operation, it requires the use of quality lubricants and compliance with the oil change schedule. It should be changed at least once every 8 thousand kilometers.
Necessity of adjusting the valves
The Subaru EZ30 engine requires the performance of periodic adjustment of the thermal gaps of the valves. This feature is associated with the absence of hydrocompensators in its design. To perform adjustment it is necessary to completely dismantle the engine from the engine compartment of the machine. Therefore, many owners neglect this condition. In practice, the critical displacement of the thermal gap from the nominal value comes when the car will pass 200 thousand kilometers of mileage (when using gas-cylinder equipment, this value of mileage is reduced several times).
Incorrectly set valve clearances do not allow the engine to operate normally. Traction is significantly reduced, fuel consumption increases, and there are problems with starting the engine in the morning (after reaching the operating temperature, the power unit stabilizes). Nominal value of valve clearances for the motor in question:
- inlet valves – 0,15-0,24 mm;
- exhaust valves – 0,20-0,30 mm.
Untimely adjustment of the valves of the engine, which operates with gas-cylinder equipment, leads to overhaul of the unit.
Replacing the cylinder head gasket
The most common problem with motors of this class is the breakdown of the gasket on one of the cylinder block heads. This problem occurs more often with the head, which is located on the right side. This situation is explained by the higher temperature in this place of the engine, which over time causes deformation of the block or the liner cup. Accordingly, there is a violation of tightness and there is a leak.
Such a problem awaits the owner at a mileage of 100 to 150 thousand kilometers. When replacing the gasket will also require replacement of lambda probes and oxygen sensors.