Subaru head gasket replacement
Subarus are some of the most popular cars here in Utah. They are extremely reliable and great in the snow however they are very prone to head gasket failure. We go over the ins and outs of getting your head gasket repaired in this article.
A bad gasket sounds innocent enough – gasket failures usually bring to mind leaks that can be remedied by sticking a drip pan under your car and keeping an eye on the oil level. Head gasket failures are not that simple and what’s worse, is that many Subaru vehicles suffer from such issues.
The head gasket seals the engine’s combustion chamber, which is where the actual explosions that cause your engine to rotate take place. Combustion pressures can reach 1,200 psi or more, putting a lot of stress on the head gasket. In addition, the head gasket is also responsible for sealing oil and coolant passages. The head gasket is installed between the cylinder head (top of the engine) and cylinder block (bottom of the engine).
In 1996, Subaru released the dual overhead camshaft (DOHC) four-cylinder engine and installed it in almost all of its vehicles including the 1996-1999 Outbacks, 1996-1999 Legacy GTs, 1998 Foresters, and the pre 2000 Impreza RS. These engines are prone to head gaskets failures, resulting in combustion gas and coolant mixing. The first sign of this problem is oily residue in the radiator and overflow tank. If the issue is not addressed, overheating, white smoke and even cracking of the cylinder block/head can occur.
You’d assume engineers would address the head gasket failures upon engine redesign, but the next generation of Subaru engines fared no better. Beginning in 2000, a lineup of single overhead camshaft (SOHC) four-cylinder engines was released, most of which suffered from the same head gasket problems as their forbearers. In fact, these gaskets fail at an even greater rate than the previous design.
The SOHC engines typically begin to leak between the coolant jacket, oil gallery and exterior of the engine. In most cases, engine oil and antifreeze leaks will be visible between the cylinder block and heads. Unless you’re crawling around under your car, this may go unnoticed until drops of coolant/oil begin to appear on your garage floor. You may also notice the smell of burning oil. The problem will get progressively worse until engine overheating occurs. It’s not uncommon for these failures to occur on vehicles that are less than 10 years old with fewer than 100,000 miles on the odometer.
There are different theories as to why Subaru head gaskets fail. One focuses on the fact that Subaru vehicles use a horizontally opposed engine with an aluminum block and aluminum cylinder heads. These metals tend to move around more than the traditional cast-iron block and aluminum heads, and since the heads are parallel to the ground in a horizontally opposed engine design, gravity aids in the development of leaks. A poorly designed head gasket material also contributes to the problem, as does corrosion in the cooling system.
Since Subaru head gasket problems are the result of a design flaw, there are no preventative measures that will prevent failure. The only action to take is to replace the head gaskets early on, when symptoms first appear. Replacing the gaskets as the first sign of a problem reduces the chance of further engine damage to the block and heads.
Instead of cutting corners, the best plan of attack is to fix the problem right – the first time. In addition to replacing the head gaskets, the following items should be replaced: new water pump, timing belt, drive belts, thermostat, idler pulleys, timing belt tensioner and tune-up parts. The engine will also need to be sent to a machine shop for proper resurfacing for the block and heads.
If you own a Subaru, you will likely have to replace the head gaskets sometime during ownership. Fortunately, if the job is done properly by trained professionals (such as us) you will never have to do it again. When you start seeing oil and/or coolant droplets on your garage floor, give us a call or contact us. We are conveniently located minutes from Salt Lake City off the I-15 in West Jordan. If you need another other Subaru repair , we do that too.