These Subaru model years were the hardest hit by head gasket problems – Jalopnik

Subaru is known for making some of the most reliable cars in the country, but that wasn’t always the case. If you owned one or knew someone who did, you’ve probably made or heard a joke about a particularly important part: the head gasket.

Several of the brand’s cars are notorious for head gasket failures, which can cost a pretty penny to replace – anywhere from $1,200 to $2,500, depending on the model and the extent of the problems. These blown gaskets can cause the cooling system to fail, eventually causing the vehicle to overheat. The problem first surfaced with the 1996 EJ25 engine, one of the worst engines of all time. The first wave of cars with internal head gasket failures included the 1996-1999 Subaru Outback, Legacy GT and LSi, as well as the 1998 model year Forester and Impreza. To solve this, Subaru introduced a multi-layer steel head gasket in 1997.

The problem reoccurred on the 2.5 liter EJ251, EJ252 and EJ253 engines. These switched from DOHC to SOHC, and this time external leaks in the area between the engine block and cylinder heads sometimes caused oil and coolant to mix. This problem can cause even more serious engine damage because mixing oil and coolant reduces engine lubrication. Affected models included the 2000–2009 Subaru Legacy, 2003–2006 Subaru Baja, 1999–2010 Subaru Forester, 2000–2009 Subaru Outback, and 1999–2011 Subaru Impreza. It is believed that the 2.5 liter naturally aspirated units have a tendency to cause head gasket failure, as the problem was not as common in other engines. The disruptions are estimated at between 120,000 and 150,000 kilometers.

Dedicated Subaru experts believe that the company has solved the head gasket problems in newer models and that the problem was fixed more than a decade ago. If you have an older Subie, you can probably avoid this problem by switching from the single-layer composite head gasket to an MLS-type gasket.