The Subaru EJ engine family predates the FB/FA, and all engines share similar design features - they're typically noticeably oversquare (the bore being significantly greater than the stroke), have traditional multi-point indirect fuel injection, and employ a belt to drive the overhead camshafts. The EJ engine was notorious for suffering head-gasket failure that took Subaru far too long to sort out. Though 2015-2021 Subaru WRX STI head-gasket problems can still occur, these issues were mostly sorted out by 2011 and will probably not affect the 2015-2021 WRXs. Meticulous maintenance with the cooling system always topped up with the correct water/antifreeze blend and topped-up oil is critical for the engine's longevity, especially because boxer engine's gaskets are always exposed to the coolant. Look for any evidence that the gaskets might be failing, like external oil or coolant leaks from the gaskets, as well as signs that the coolant and oil have mixed. Oil with coolant in it will appear milky, and oil will turn coolant murky and sludgy - and block cooling passages. Oil levels are critical too; low oil levels quickly lead to problems such as overheating, excessive wear and - in boxer engines in particular - to oil starvation of engine components under cornering forces.
The EJ257 can suffer from turbo failure, and this might happen as soon as 50,000 miles on abused and/or neglected engines, although it should typically last until 125,000 miles. Modifications and increased boost bring on failure earlier. A failing turbocharger might develop a whining sound, a drop in power, and will cause the engine to consume oil. Ringland failure is also not uncommon on many EJ engines such as the EJ257 with their high-silicone pistons that are very strong, but also relatively brittle. Ringland failure due to detonation, heat, bad tunes, high intake temperatures, abusive driving, and low-octane fuel will lead to improper support of the rings, but there are also other internal failures of various components that will usually be announced by knocking or ticking sounds, compression loss, smoke from the exhaust, loss of oil pressure, or excessive oil consumption. A reliable EJ257 must be stock standard, meticulously maintained, with all its fluids topped up, and running sweetly and quietly, because any repair will be expensive.
Oil leaks are common on boxer engines and one of the relatively common Subaru WRX STI problems, with the EJ257 being the exception, is with the seals and gaskets usually starting to leak from around eight years or 100,000 miles. This most commonly affects the valve-cover gasket, although oil-pan gaskets and main seals can also start to leak.
Mileage:Head gaskets on affected engines usually fail from 100,000 miles. Turbochargers can fail from 50,000 miles but usually last until 125,000 if kept stock. Many of the internal failures are due to mods, abuse, lax maintenance, overheating, or low oil levels and not mileage, which is why a full service history and a once-over by an expert is important on these cars.
Cost:替换头垫片将花费超过1美元,000. Used turbochargers may be available for $500, but one from Suburu will cost at least $1,000, plus $600 to fit. Valve-cover gaskets will probably not cost more than around $50, but the labor for fitment is about $400.
How to spot:吹头垫片可能泄漏冷却液和/或油the outside of the engine, so look for external leaks, a wet engine, and liquids on the floor underneath the car. A breach between water and oil galleries will cause coolant and oil to mix, turning the oil murky and milky and turning the coolant oily and sludgy - and the oil cap will have a foamy/oily deposit on it. Both coil and coolant levels will drop, overheating may occur, and steam (coolant) and blue smoke (oil) may come from the exhaust with the engine hot. Gasket failure may cause air to enter the cooling system and air in the heater core will cause the heater to blow cold - and bubbles will show in the coolant overflow reservoir with the engine idling. Various internal component failures like con-rod bearings, piston ringlands, and rings may cause knocking/ticking sounds, excessive oil consumption, smoke from the exhaust, or a drop in oil pressure. Oil leaks will be visible on the outside, with a wet engine, oil in the spark-plug holes, and on the floor. When it drips on hot engine parts, puffs of smoke and a burnt-oil smell will occur. The oil level might be low, with all the potential problems that follow on from that.