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Title: Collapsed Lifter
Problem: A street rod owner says that his 1983, 350 small block Chevrolet engine was recently rebuilt. All lifters were replaced with new ones and broken-in according to the lifter manufacturer's recommendations. After it was completed and run about 20 miles, there was a noticeable clicking sound coming from the engine. The valves were checked for the correct adjustment. All but one intake valve had the correct adjustment. One valve could not be adjusted to get rid of the clicking sound. Also the engine had a very distinct miss at all rpm. What could be the problem?
Solution: The first thing to check is the clicking on the one intake valve. Since the valve cannot be adjusted, this is a sign of a collapsed lifter. A collapsed lifter has no hydraulic pressure being built up inside. After checking with the lifter manufacturer, they indicated that possibly there was a small unnoticeable bur on the lifter plunger. See arrow. After removing the lifter, it was found that the inside piston or plunger of the lifter was stuck in the down position, essentially making it a solid lifter. So, no hydraulic adjustment could be made. Both the intake and exhaust lifters were replaced according the manufacturer's recommendation, and this corrected the problem. After replacing the lifters, make sure to follow the manufacturer's recommended procedure to break in the new lifters.
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Problem: A street rod owner says that his 1983, 350 small block Chevrolet engine was recently rebuilt. All lifters were replaced with new ones and broken-in according to the lifter manufacturer's recommendations. After it was completed and run about 20 miles, there was a noticeable clicking sound coming from the engine. The valves were checked for the correct adjustment. All but one intake valve had the correct adjustment. One valve could not be adjusted to get rid of the clicking sound. Also the engine had a very distinct miss at all rpm. What could be the problem?
Solution: The first thing to check is the clicking on the one intake valve. Since the valve cannot be adjusted, this is a sign of a collapsed lifter. A collapsed lifter has no hydraulic pressure being built up inside. After checking with the lifter manufacturer, they indicated that possibly there was a small unnoticeable bur on the lifter plunger. See arrow. After removing the lifter, it was found that the inside piston or plunger of the lifter was stuck in the down position, essentially making it a solid lifter. So, no hydraulic adjustment could be made. Both the intake and exhaust lifters were replaced according the manufacturer's recommendation, and this corrected the problem. After replacing the lifters, make sure to follow the manufacturer's recommended procedure to break in the new lifters.
Back to Troubleshooting Clinics
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