Re: 1998 Volvo Penta 5.7 GS Compression?
Below is a copy and paste from a Volvo service manual for your engine.<br /><br /><br />Test Conclusion<br />The indicated compression pressures are considered normal if<br />the lowest reading cylinder is within 75% of the highest.<br />Example:<br />ff the highest pressure reading was 140 PSI, 75% of 140 is 105.<br />Therefore, any cylinder reading tess than 105 PSi indicates an<br />improperly seated vaBve, worn valve guides, piston, cylinder, or<br />worn or broken piston rings. Any cylinder reading 105 PSi or<br />greater is within specifications, and compression is considered<br />normal.<br />if one or more cylinders read low, squirt approximately one<br />tablespoon of engine oil on top of the pistons in the low reading<br />cylinders. Repeat compression pressure check on the cylinders.<br />1. if compression improves considerably, the piston rings are at<br />fault.<br />2. if compressiond oes not improve, valves are sticking or seating<br />poorly, or valve guides are worn.<br />3. If two adjacent cylinders indicate low compression pressures<br />and squirting oil on the pistons does not increase the compression,<br />the cause may be a cylinder head gasket neak between the<br />cylinders. This problem could allow engine oil and/or coolant to<br />enter the cylinders.
). If I saw a 105 next to a 140, I'd be getting the quoting pad out.<br /><br />Do you agree with VP's statement, Don?<br /><br /><br />Aldo