A weak radiator cap not holding pressure may not let all of the coolant get hot enough to boil but there are areas within the engine that are now boiling. Scenario: The radiator cap is weak (which we run into all the time on Subarus). Since we must have the coolant in contact with the metal to perform it’s heat transfer duties we now have a problem. There are areas throughout the engine where the coolant circulates that become very hot. Add to that a radiator cap that holds 13psi and now you have coolant that won’t boil until 300 degrees. A 50/50 mix of anti-freeze and water has a boiling point around 265 degrees. This can raise the boiling point depending on the mix of coolant/water an additional 35-40 degrees. Most radiator caps for stock vehicles keep the system pressurized between 13-15psi. The radiator cap keeps coolant in a sealed system, allows overflow to exit and return as coolant expands and contracts, but most importantly it raises the boiling point of the coolant in the system by keeping the cooling system pressurized. Subaru Radiator Caps OLD vs NEW Subaru Radiator CapĬlick here to view our cooling system products If any of the 3 components are failing or inferior, problems could develop even sooner. There are 3 very important items that may individually have a negative impact on the coolant’s ability to do it’s job. It must have adequate flow to move the heat away from the internal areas of the engine and it must remain in contact with the areas it’s trying to cool.
Two important things must occur to for the coolant to do it’s job. The coolant remains in contact with the metal and is able to absorb heat, travel to the radiator and release the heat to the atmosphere. Within the engine block, coolant is circulating to keep the engine cool due to internal combustion occurring.
Failure of sealant, improper torque, surface imperfections in the cylinder head or engine block and of course heat or excess heat all can cause failures.Ĭlick here to view our quality head gaskets Subaru head gaskets can fail for numerous reasons.
#Subaru outbank coolant reservoir bleed screw how to
In another post I’ve gone into further detail about Subaru head gaskets but for today I would like to offer some suggestions on how to help prolong your current gaskets. We’ve done a good portion of those ourselves. Since the 2.5 liter Subaru engine was put into production there have been thousands of head gaskets replaced across the country. We’ve got a few maintenance tips below to help put off head gasket failure as long as possible. Our first goal is making your head gaskets last as long as possible. If you own a Subaru you know what I mean. Subaru head gaskets are about as hot of a topic as national health care lately. Mike Corbin Septem441 comments Subaru Engine, Subaru Maintenance and care, Subaru Technical