Another oft-forgotten bit of info is this: The vacuum pump empties into the crankcase area. So, if your vacuum pump is working hard, for instance, evacuating the vacuum resevoirs, then it will be pumping air into the engine, increasing the "blow-by" at the filler cap.......

Best time to check blow-by is after running engine at high-way speeds for a good time and then coming to a smooth stop (NO BRAKE PEDAL PUMPING!!) so that the Vacuum pump isn't contributing very much..........

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-Matt

EPA Section 609 Certified MVAC Technician
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Oil Burner Kartel Member #10

Ahh the smell of Diesel Fuel, it's like coffee in the morning!

My Car:

1982 300SD Turbo Diesel (231,500 miles!) RIP

1984 300SD Turbo Diesel Custom (235,500 mi on driveline.) - On Road!!

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