How long should valve seals last?
Why do Valve Stem Seals Fail? Valve stem seals often last more than 150,000 miles under normal driving conditions. Infrequent oil and filter changes may cause valve stem seals to fail prematurely. Improper installation often causes valve stem seals to fail shortly after installation.
Will a compression test show bad rings?
Cylinder compression tests are performed to identify any cylinders that have poor compression. If a cylinder has low compression, perform a wet compression test to indicate whether it’s a bad valve, head gasket, or worn piston rings causing the problem.
What are the symptoms of bad valve seals?
Bad valve seals nearly always show an intermittent problem of oil burning, whereas worn piston rings and valve guides will smoke during all times of engine operation and never disappear.
When do bad valve seals start to smoke?
Yet the smoke will eventually disappear; after long engine operation or during periods of hot weather. Bad valve seals nearly always show, an intermittent problem of oil burning. On the other hand, worn piston rings and valve guides will smoke; during all times of engine operation and never disappear.
Can a bad valve stem seal cause oil burning?
Bad valve seals nearly always show, an intermittent problem of oil burning. On the other hand, worn piston rings and valve guides will smoke; during all times of engine operation and never disappear. So, debris from deteriorating valve stem seals, is another concern; that can cause additional problems inside an engine.
What causes a compression leak in the head gasket?
More likely however is the scenario where the pistons themselves are intact, but the piston rings were damaged from overheating and are failing to seal the gas inside the cylinder. If you have low compression in all cylinders, this is often the culprit. Also, your compression leak may not be in the pistons or head gasket but in the valves.