Most of us know the procedure involved in carrying out an engine compression test. Right ? Engine hot, accelerator pedal fully depressed, and turning over engine for about six or seven revolutions. Normally, to carry out the test, it needs two people, namely one to activate the turning of the engine, and the other that holds the compression gauge in the spark plug hole.
Now, there MAY WELL BE another method of carrying out the test. Some gauges are supplied with a screw type fitting which, of course, can be screwed into the spark plug hole. The English LUCAS compression tester features this type of fitting. I had one of those, and actually decided to run the engine with the tester plugged in, checking ONE cylinder at a time. The readings were as follows at the time, back in February 2005.
1 - 88 lbs. 5 - 95 lbs.
2 -117 lbs. 6 -100 lbs.
3 - 80 lbs. 7 -100 lbs.
4 -100 lbs. 8 - 80 lbs.
From those readings, one could be forgiven for thinking that the engine was completely worn out. Yet, there were no real issues for about three years until the head gasket developed a leak at the back of No.4 cylinder. That problem, of course, was rectified in 2009 by a valve grind and de-coke. The engine has run well since then - no oil problems, no smoke on the over-run etc. I am interested what others are thinking about the method of checking the compression with engine running. Regards Styria.
Now, there MAY WELL BE another method of carrying out the test. Some gauges are supplied with a screw type fitting which, of course, can be screwed into the spark plug hole. The English LUCAS compression tester features this type of fitting. I had one of those, and actually decided to run the engine with the tester plugged in, checking ONE cylinder at a time. The readings were as follows at the time, back in February 2005.
1 - 88 lbs. 5 - 95 lbs.
2 -117 lbs. 6 -100 lbs.
3 - 80 lbs. 7 -100 lbs.
4 -100 lbs. 8 - 80 lbs.
From those readings, one could be forgiven for thinking that the engine was completely worn out. Yet, there were no real issues for about three years until the head gasket developed a leak at the back of No.4 cylinder. That problem, of course, was rectified in 2009 by a valve grind and de-coke. The engine has run well since then - no oil problems, no smoke on the over-run etc. I am interested what others are thinking about the method of checking the compression with engine running. Regards Styria.
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