Common EJ257 Long Block Problems and How to Prevent Them

The EJ257 is one of the most well-liked performance motors Subaru has ever built, gracing models like the WRX STI and quickly building a solid reputation for strong mid-range torque and tuning potential. Of course, sharing a similar fate to many turbocharged engines, it carries its weak spots that owners and builders alike need to understand. 

Ringland Failure on the EJ257 Long Block

One of the most commonly reported problems with the EJ257 long block is ringland cracking. Most of the time, these failures occur on cylinder 2 or 4 and are usually caused by:

• Too much heat
• Poor tune up or running lean
• High boost on stock pistons
• Poor quality fuel

When a ringland fails, common symptoms include misfires, loss of power, blow-by, and uneven compression numbers.

Prevention of Ringland Failure

The best preventive steps include the following:

• Run a conservative tune from a reputable tuner
• High-octane fuel is recommended for a hot climate
• Avoid over-boosting on stock pistons
• Ensure proper cooling with things like upgraded intercooler/radiator

The solution to this is to use forged pistons, which many owners do when rebuilding their EJ257 long block, in order to eliminate this weak point entirely.

Oil Starvation and Bearing Failure

Other than head gasket failure, bearing failure is another well-known EJ257 long block problem. The EJ platform is highly dependent on proper oiling; any disruption may cause spun rod bearings.

Usual causes include the following:

• Low oil level
• Oil pickup cracks
• Track driving with no proper oil control
• Sludge buildup from extended oil-change intervals

Preventing Bearing Failure

• In case of protecting the bearings on your EJ257 long block
• Check oil frequently, the EJ257 can be an oil drinker
• Upgrade the oil pickup in particular for high-performance builds
• Employ a high-quality synthetic oil, changing it much more frequently
• For aggressive driving, consider a baffled oil pan or air-oil separator

One of the most cost-effective ways to prolong the life of an EJ257 long block is by doing routine oil maintenance.

Head Gasket Leaks on the EJ257 Long Block

Although not as common as older EJ engines, the EJ257 long block can still experience head gasket leaks, especially at higher mileage or after overheating. Turbocharged engines run hotter, which increases the risk of gasket breakdown.

How to Prevent Head Gasket Issues

• Maintain the cooling system, the radiator, hoses, thermostat, and coolant
• Avoid overheating at all costs
• Use OEM or performance head gaskets during rebuilds
• Ensure the block and heads are properly machined when assembling

Detonation and Poor Tuning

The EJ257 long block is sensitive to tuning quality. Aggressive or poorly executed tunes can cause detonation (knock), which leads to catastrophic failures such as:

• Cracked pistons
• Melted spark plugs
• Damaged cylinder walls
• Blown head gaskets

How to Prevent Detonation

• Always get tuned by an experienced Subaru tuner
• Use monitoring tools like an access port to watch DAM, knock feedback, and AFR
• Keep the intake tract leak-free
• Avoid cheap fuel, especially on high-boost setups

Cooling and Overheating Issues

Turbocharged engines generate significant heat, and the EJ257 is no exception. Overheating can warp heads, weaken gaskets, and significantly shorten overall engine life.

How to Prevent Overheating

• Upgrade the radiator if you drive aggressively or in hot climates
• Ensure the intercooler is functioning properly
• Replace failing water pumps or thermostats immediately
• Keep the coolant system bled to avoid air pockets

Final Thoughts: Keeping Your EJ257 Long Block Healthy

By being proactive with maintenance, using good-quality fuel, and using reputable tuners, you can greatly increase the life of your EJ257 long block and enjoy its performance without unexpected breakdowns.