Join Date: Feb 2003
Location: New Jersey USA
Originally Posted by bruce1976spider
Closed throttle DOES make the resulting reading lower!!
Well, of course it does. And the reason is quite simple. An internal combustion engine is a pump. An air pump to be more precise. The output is therefore dependent upon, among other things, it's input. The lower the input, the lower the output. This is why closed throttle compression readings are ALWAYS lower then WOT readings.
The dry/wet compression numbers do tell a bit of a story. The reported symptom is 250 miles/quart of oil. If all of this oil was coming up past the oil control rings, the cylinders walls would be oil coated. This could give false high compression readings as the dry test is effectively a wet test. However, the delta between the dry and wet test readings is too high. Therefore, the oil rings are NOT the major source for the oil consumption.
Moot point really as the dry/wet readings indicate compression problems anyway.
Series 2 USA 1750 GTV (in Series 1 European clothing)