What sets Cascadia apart from other shops when replacing Subaru head gaskets?
We fully remove the engine assembly.
A lot of repair shops manage to replace Subaru head gaskets while leaving the engine assembly in the engine bay. This works fine and get the job done. But there are some major benefits to removing the entire engine assembly from the vehicle.
1. We can thoroughly inspect the engine all the way around. When we have the engine out and on an engine stand we can easily turn the crank assembly and see 360 degrees of each cylinder wall. With the engine in the car mated to the transmission there are important seals on the back of the engine which cannot be seen or accessed. Pulling the engine allows us to check the wrist pin access plate, oil separator plate and the rear main seal. We find that 6 out of 10 Subaru’s have oil seepage or leaks from these components during our head gasket repairs.
Pictured to the left:
Wrist pin access plate.The engine in these photoswas very well cared forand was not leaking from the access plates.
Pictured to the right:
Oil separator access plate and rear main seal below
2. Engine bays are cramped. Other engine components, wiring harnesses and structural parts commonly get in the way of being thorough. With the engine out we can meticulously clean and prep the cylinder deck without any encumbrances. This is very important to the longevity of a head gasket repair. A cylinder deck with bits of old gasket and gunk stuck to it will not make for a good mating surface and can easily lead to another premature failure.
Pictured: EJ25 cylinder deck before and after a thorough preparation. This engine was particularly well cared for and had only 100,000 miles. Came in with clean oil and proper blue coolant. The carbon build up shown on the pistons is normal and is less than what we typically see.
OEM Gaskets and Seals
This is an important distinction. There is plenty of debate to be found on which gasket brand, design, etc. is the best. But we have a proven record of success using OEM “STI gaskets”.
1. STI gaskets are fully interchangeable onto the SOHC non-turbo EJ25 and are the heavy duty multi-layer steel gaskets that come from the high performance EJ257 found in the Impreza WRX STI.
2. We use these gaskets because the EJ257 rarely exhibits head gasket failure when properly cared for. We’ve had 12 year old, 200,000 mile WRX’s in our service department on the original gaskets showing only minor oil seepage. Why these are gaskets are not installed on every Subaru from the factory is a mystery to us.
3. The multi-layer steel gaskets do not require the use of Subaru coolant or Subaru coolant conditioner in order to have a reasonable lifespan. A good quality green coolant that is regularly serviced is sufficient.
Left: Original single layer EJ25 head gasket which had not blown yet. Was only leaking oil.
Middle: New single layer OEM gasket. Comes in the non turbo EJ motors from the factory.
Right: New EJ257 STI head gasket. Multi-layer steel. You can see the reinforcements around the oil and water passages.
Thorough cylinder head preperation
A clean and flat mating surface is very important to the longevity of a gasket in any application. Which is why we thoroughly clean, inspect and resurface cylinder heads.
Left: Freshly pulled EJ non turbo cylinder head
Right: Pair of dual cam turbo heads and engine block back from the machine shop after resurfacing. Oil separator access plate and rear main were leaking badly on this motor.
