What exactly does blown mean anyway? The head gasket in your engine is the gasket that seals the cylinder head of the engine to the engine block. There are coolant and oil passages that transfer the oil and coolant from the engine to the head and back. The reason for these passages, is for the oil to lubricate the valve train, and the coolant to remove heat from the cylinder head. The other job of the head gasket is sealing the top of the cylinder to keep the compression contained.
Head gasket problems arise generally due to poor maintenance of the cooling system. Acidic coolant can begin to eat away or erode the sealing area of the coolant passages in the gasket. This can cause a weak area and a leak can start to form. The head gasket leaking can travel either internally or externally. An external leak is visible outside the engine, an internal leak means that coolant can seep into oil passages or erode the compression sealing ring in the head gasket allowing coolant to enter the cylinder or compression to enter the cooling system. This is what we call a “blown” head gasket.
While an improperly maintained cooling system can cause head gasket failure. There are some vehicles that are simply prone to head gasket failure, this is due to the composition of the head gasket material and overall engine design. A vehicle that has overheated due to coolant loss or a cooling system restriction or failure, can also accelerate head gasket failure.
The best way to prevent a head gasket failure is to maintain the cooling system in your vehicle. The recommended maintenance is to flush the coolant in your vehicle approximately every 2 years or every 30,000 miles. It is important to keep the coolant protection level in our climate at -34 degrees fahrenheit. The PH balance of coolant should be at 9.5 on the ph scale. As ph drops the coolant becomes acidic and can eat away or erode gaskets, rubber, lead, solder joints, aluminum and even steel.
The other important factor, is to take care of cooling system issues as soon as they present themselves. Repair coolant leaks, restrictions or malfunctions as soon as they are detected. This will help prevent coolant loss and overheating. If your vehicle does start to climb in temperature while driving, shut it down immediately and have it towed to your trusted repair facility for a diagnosis and repair.
Symptoms of head gasket failure can include:
1) No heat coming from your heater.
2) Rising temperature gauge.
3) Boiling or percolating coolant when the engine is shut off.
4) Loss of coolant or coolant consumption and no obvious coolant leaks.
5) White smoke billowing from the tailpipe of your vehicle.
6) A blown out radiator.
7) Coolant in your oil.
8) Coolant in the spark plug holes.
If you are experiencing any of these symptoms we recommend having your vehicle checked out as soon as possible. A blown head gasket repair can be very costly, so preventing a head gasket failure is definitely in your best interests.
Steve and Karen Johnston are owners of All About Automotive, providing auto repair and auto maintenance in Historic Downtown Gresham. If you have questions or comments, call them at 503-465-2926 or email them at [email protected], you can also visit our website at allaboutautomotive.com.