What are the causes of insufficient compression in cylinder two?
2 Answers
The causes of insufficient compression in cylinder two are: 1. Severe wear of piston rings, resulting in reduced sealing effectiveness; 2. Scratches or abnormal wear on the cylinder wall; 3. Poor sealing of the valve seat or spark plug seat; 4. Damage to the cylinder gasket. The solutions for insufficient compression in cylinder two are: 1. Replace the valve oil seal; 2. Replace the piston and piston rings; 3. Install a cylinder liner; 4. Replace the valve spring; 5. Replace the cylinder head gasket. The symptoms of insufficient compression in cylinder two are: 1. Excessive smoke escaping from the oil filler opening in the crankcase; 2. Lubricating oil in the oil pan becomes dirty and overheats easily; 3. Noticeable decrease in engine power while driving.
I just helped a friend deal with a similar situation last month. Low compression in cylinder two is most commonly caused by valves not sealing properly, which could be due to excessive carbon buildup jamming the valves or the valves themselves being deformed and leaking. Worn piston rings can also lead to this issue, especially in older cars with over a hundred thousand kilometers on them, where the piston ring gaps have widened, reducing sealing efficiency. Sometimes, a blown head gasket can allow coolant to leak into the combustion chamber, which will definitely prevent pressure from building up. Using a borescope provides the most direct view, allowing you to observe whether there’s any scoring on the cylinder walls. The repair isn’t too complicated, but it requires removing the cylinder head for a thorough inspection—replace the valves if necessary and the piston rings if they’re worn out.
