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Old 01-07-2013, 03:39 AM
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Stretch Stretch is offline
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Join Date: Sep 2009
Location: Somewhere in the Netherlands
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Quote:
Originally Posted by Diesel911 View Post
Well it still does not answer your question as to what the Mercedes Service Manual would have to say.

Thanks for digging that up; it is in post #37

"At idle speed I removed the Rubber Elbow from the top of the Valve Cover and covered and started counting 1000 one; 1000 two and so on until the Engine Shut Down.
It took 10 seconds for the Engine to shut down at an approximate pressure of 3.1 psig."

The inside of the Fuel Injection Pump is exposed to the crankcase pressure by way of the area in front of the IP that the Oil drains out of and one side of the Shutoff Diaphragm is also exposed to the same pressure.
Can you clarify if this happened at idle?

I only ask because "people say" (I will provide a reference in a bit honest!) that at low engine speeds the piston rings are not as effective as at high engine speeds => so they are meant to seal better at high revs; but because the engine is pumping a greater volume of air through itself at higher engine speeds blow by is more likely to be greater at high revs. This isn't the full story though because it doesn't include the effect of engine loading which can also induce greater blow by...

...after all that (deep breath!) what was happening to and within the engine when the measurement was made must be considered as well.

Have you had problems with the engine conking out under different conditions? Or have you just noticed this at idle.
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