The Subaru EZ30 Engine Issues

The Subaru EZ30 Engine Issues. The Subaru EZ30 is a six-cylinder engine that debuted in the United States in 2001. The EZ30 is most usually associated with Subaru Legacy and Outback vehicles. The engine’s design was so dynamic that Subaru experimented with a turbocharged version for a concept car displayed at the 2003 Geneva Motor Show. In 2009, Subaru phased out the EZ30 engine in favour of the EZ36. The EZ30 design was widely associated with a few minor issues. The engine difficulties and reliability of the Subaru EZ30 are discussed in this article.

The Subaru EZ30 Engine Issues

What Vehicles Make Use of the Subaru EZ30 Engine?

This engine’s two variants produce 217-240 horsepower and 213-219 lb-ft of torque. The engine was initially presented to the market for the 2001 Subaru Outback H6-3.0. Subaru sought to produce a dependable and cheap engine system with adequate power. Subaru discontinued the EZ36 in favour of a new turbocharged four-cylinder engine line. Please see our prior article on the most common engine problems with the EZ36. Now, let’s look at some of the Subaru EZ30 engine models and their most prevalent problems.

The EZ30 phase one and two are present in the following Subaru cars sold in the United States:

  • Legacy (from 2002 through 2019)
  • (2001-2019) Outback/Lancaster
  • Tribeca Film Festival (2006-2014)

Typical Subaru EZ30 Engine Issues

The following are some of the most prevalent Subaru EZ30 engine problems:

  • Oil Spills
  • Failure of the Auto Tensioner
  • Failure of the A/C compressor

Throughout this post, we will analyse each major problem, its severity, and some of the necessary repairs. These issues will not affect every Subaru EZ30 motorist. However, we’ve discovered that these are some of the most prevalent problems that EZ30 drivers face.

It’s a basic fact that engines have a wide range of issues. Any engine that experiences time or heavy miles is sure to experience certain troubles or failures. However, the Subaru EZ30 engine is still widely used, particularly in older Outback versions. The Subaru Outback (and Baja) have a cult following because to their unusual design and features. Subaru owners in general praise their vehicles’ dependability, although some frequently encounter the issues detailed below. With that said, let’s take a closer look at the problems outlined above with the Subaru EZ30 engine.

1) Oil Leak Issues with the Subaru EZ30

Subaru EZ30 oil leaks are most likely the most common issue. Many gaskets, seals, and o-rings are used in internal combustion engines. These parts tend to wear out and leak oil with age and mileage.

This is especially true for the EZ30 engine, which is getting old and has a lot of miles on it. Anyway, we’ll look at some of the most prevalent locations for these oil leaks below.

Two distinct oil pans

For a variety of reasons, the Subaru EZ30D engine is prone to oil leaks. Within this engine arrangement, there are two different oil pans. The upper and lower oil pans built into the engine system simply double the risk of an oil leak. As a result, a failed sealant has a twofold risk of occuring. Dual oil pans are frequently a design mistake for this reason. The EZ36 also has two oil pans and oil leak issues.

Failure of the PCV Valve

PCV valve failure is another typical cause of oil leaks and other problems. The PCV (Positive Crankcase Ventilation) valve aids the engine in controlling pollutants. The valve directs gases produced by the engine’s crankcase back to the combustion chambers. This permits the gases produced by the crankcase to escape without causing damage to your vehicle. This technique also benefits the environment by emitting less hazardous gases.

When a PCV valve fails, more and more engine sludge accumulates over time. A faulty PCV valve can cause numerous seals to fail, resulting in annoying oil leaks that must be repaired. Replace or maintain the PCV valve if you want to take care of your EZ30 engine and protect the environment.

O-Ring sealant failure on the oil cooler

The oil cooler of the EZ30 engine has an O-Ring-shaped seal that is prone to failure and oil leaks. This seal connects the oil cooler to the engine block. A huge buildup of oil below the car, specifically on the oil filter, oil cooler, or coolant lines, can be used to diagnose this. As a result, if you detect oil leaks in these spots, they are most likely the result of a failed o-ring seal on your oil cooler.

Finally, ensure that neither of the separate oil pans has lost its seal. Maintain or replace a broken PCV valve to safeguard both your engine and the environment. Finally, if you see significant oil buildup on the undercarriage’s bottom and around the oil cooler, inspect the oil cooler’s o-ring seal. These three regions are some of the most prevalent sources of oil leaks in the EZ30 engine.

2) Failure of the EZ30 Belt Auto-Tensioner

The Subaru EZ30 phase 1 and 2 engines use a serpentine belt, which means that one belt controls all of your accessory drives and has one auto-tensioner to keep the belt tensioned. The auto-tensioner’s bearings can wear out over time and require repair. This auto-tensioner is a spring-based mechanism that regulates serpentine belt tension. Fortunately, the EZ30’s auto-tensioner includes a notch system that alerts drivers when their belt is stretched to the point of needing replacement. As the spring wears and the bearings deteriorate, the entire assembly can create loud banging noises and engine damage.

A single serpentine auto-adjusted belt is likewise used in the EZ36. However, Subaru’s EJ series engines typically have two manual belts, whilst the EZ30 and E36 only have one. A broken belt can cause an abrupt loss of power steering as well as the engine’s cooling system to fail. A new belt can cost between $25 and $75, with labour fees ranging between $75 and $200 depending on the shop. Fortunately, this issue is simpler and less expensive to resolve than the majority of the others discussed in this article.

Symptoms of Worn Belt/Auto-Tensioner Failure

The following are some signs of Subaru EZ30 belt problems:

  • Engine bay knocking or screaming noise
  • Power steering failure
  • Air conditioning failure
  • Overheating of the engine
  • Belt has a crack in it.
  • The EZ30 notch system indicates wear.

3) EZ30 AC Compressor Issues

A faulty air conditioner can cause more problems for you and your vehicle than just a hot summer. The a.c. compressor in the Subaru EZ30 has frequently been reported to be problematic by drivers. This problem is most typically connected with EZ30D phase 1 engines. However, aside from the original 6 cylinder Subaru engine, the same issue can be a typical annoyance for many engines.

Failure of the EZ30 Flat-6 Electromagnetic Clutch

The electromagnetic clutch that controls the a.c. compressor can fail, leading the vehicle to stop producing cold air. The spacing between the compressor’s electromagnetic clutch and the assembly pulley must be specified. Over time, this gap can either compress or expand up, resulting in a gap that is too narrow or too large for the electromagnetic clutch to function effectively. This is the problem that prevents the car’s air conditioning unit from producing cold air. Simply add or remove shims until the gap mentioned is restored to engine specification.

Refrigerant Lines That Are Leaking

An a.c. compressor converts the refrigerant in an automobile through a chemical exchange into cold compressed air. The sealing of the rings connecting the refrigerant lines to the compressor might potentially fail and cause the entire system to fail. To keep your engine’s refrigerant levels stable, make sure your lines are properly sealed. These are, once again, o-rings that connect the refrigerant lines to the compressor. Up until the late 2000s, Subaru drivers experienced significantly more recurring difficulties, mainly with the refrigerant lines.

Failure of the Subaru EZ30 Revolution Sensor

Another potential source of trouble is the revolution sensor, which is placed on the back of the air compressor. The rpm of the a.c. compressor is monitored by this sensor. It’s critical to keep an eye on the compressor’s rpm while using a serpentine belt. If the rpm in the compressor does not match the specified speed, the sensor detects it. If the speeds are not equal, the sensor will disengage the previously mentioned clutch, resulting in a.c failure. The entire cost of a newly replaced a.c compressor can exceed $1000, depending on where the parts are bought and overall labour charges.

Causes of Common AC Compressor Failure

  • Failure of an electromagnetic clutch
  • Line(s) of refrigerant leaking
  • Failure of the revolution sensor

Related : The Toyota 1JZ vs 2JZ – Comparison & History

Engine Reliability of the Subaru EZ30

So, how reliable are the EZ30 phase 1 and 2 engines? Subaru owners often identify this engine with dependability and longevity. A decent benchmark for the EZ30 engine’s lifespan would be 180,000 miles. That’s an astounding number of miles for any automobile, regardless of price. In terms of engine reliability and durability, we would rate the EZ30 mk1 and EZ30 mk2 as above-average.

The Subaru EZ30 may be a solid everyday driver with regular maintenance and the use of high-quality oil. That could, however, be said of numerous cars with far more horsepower than the EZ30 and EZ36 engines. It’s also worth noting that the Subaru EZ30s have significantly higher fuel usage (when compared to similarly-sized automobiles from the same era).

Potential timing cover and valve cover leaks are also hazards to be aware of. When we were specifically looking into difficulties with the PCV valve, we briefly discussed this. However, leaks and failed sealants appear to be a recurrent theme in both the EZ30 and EZ36 engines. The Subaru EZ30’s dependability can be affected by a variety of factors. We discovered that when properly maintained, these engines are likely to be overall trustworthy and reliable everyday drivers.

Summary of EZ30 Common Issues

In terms of design, the EZ30 engines have no major problems. However, just like any other engine, dependability and longevity are contingent on adequate maintenance. Minor defects can lead to an expensive repair bill, if not total engine failure. Consider the substantial costs connected with our previously described faulty a.c compressor. Even the less expensive issues discussed above can cause severe engine damage.

As previously stated, there are numerous potential causes of oil leaks in the EZ30 engine system. Simply having two oil pans increases the likelihood of an oil spill. Leaking o-rings on the oil cooler can also be a problem, generating buildup on the car’s underbelly and the cooler’s pipes. Check to see if your PCV valve is open and working properly, allowing for adequate emissions.

Many drivers have reported chain tension concerns, particularly with the earlier period phase 1 engine. If the chain tensioner fails, the entire assembly will most likely need to be replaced. This is one of several possible causes of overheating in your Subaru engine. The AC compressor is another prevalent EZ30 issue. Apart from failing to produce cold air, a faulty a.c compressor might cause a slew of other problems for your engine.