I have seen this fairly often. The 165 and 175 readings are the normal ones. The low readings on cylinders 1 and 3 is probably caused by worn cam lobes. The same lobes operate the opposing cylinders. A leak-down test will more accurately determine if the valves or rings are leaking. If the performance is acceptable, I wouldn't worry about the worn lobes. Dennis -----Original Message----- From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Larry and Avery Sent: Thursday, May 06, 2004 6:27 PM To: vanagon@GERRY.VANAGON.COM Subject: Odd Compression Readings Earlier this week I was at Frank Condelli's for some Spring Tune-Up. He measured my compression as 130, 165, 125, 175 psi for cylinders 1 to 4. This is an old engine with over 250,000 kms (about 155 K miles) with original heads and gaskets. So we were quite surprised. Our conclusion was that heavy deposits must have built up in cylinders 2 and 4. Why not 1 and 3 we don't know. My question is: 'What is the best and safest way to reduce/remove these deposits without removing the heads?' At present, I switched to high octane fuel and have added a large slug of Marvel Mystery Oil to the gas with a full fill. The hope is that the Marvel will dissolve away the deposit over time. The high octane is simply because the compression requires it. Has anyone experienced this odd compression before? How did you reduce it? Thanks in advance Larry ..........There are 10 kinds of people in this world. Those who can read binary and those who cannot........... |
Please note - During the past 17 years of operation, several gigabytes of
Vanagon mail messages have been archived. Searching the entire collection
will take up to five minutes to complete. Please be patient!
Return to the archives @ gerry.vanagon.com
The vanagon mailing list archives are copyright (c) 1994-2011, and may not be reproduced without the express written permission of the list administrators. Posting messages to this mailing list grants a license to the mailing list administrators to reproduce the message in a compilation, either printed or electronic. All compilations will be not-for-profit, with any excess proceeds going to the Vanagon mailing list.
Any profits from list compilations go exclusively towards the management and operation of the Vanagon mailing list and vanagon mailing list web site.