E36 Turbo Scavenge Pump

[crivers811]

Going to be installing my scavenge pump on m3 pretty soon... Is it necessary to have a sump in between the drain and scavenge pump?

[pbonsalb]

It seems to help. Some cars have smoking issues, some don’t. Others have used a vent line instead. I used a tiny sump right under the turbo and never had an issue. Consider returning to the crankcase vent stem on an obd2 dipstick, but still a 1/4” hole right through the middle of the dipstick just below the point where the stick enters the oil pan. Alternatively if you have the pan off, weld a 10AN return on top of the pan on that side but closer to the rear of the motor so you need less line.

[crivers811]

Thanks a lot!


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[crivers811]

It seems to help. Some cars have smoking issues, some don’t. Others have used a vent line instead. I used a tiny sump right under the turbo and never had an issue. Consider returning to the crankcase vent stem on an obd2 dipstick, but still a 1/4” hole right through the middle of the dipstick just below the point where the stick enters the oil pan. Alternatively if you have the pan off, weld a 10AN return on top of the pan on that side but closer to the rear of the motor so you need less line.

I currently have a 10an fitting welded on the top front most part of the pan. Will it be an issue if I return the pump to it?


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[pbonsalb]

No. I have returned both below the oil level and above it without issue. The pump runs full time so it is always trying to evacuate oil and the oil should not be pooling up and backing into the turbo and causing smoke. If you do have issues, look into a check valve. Some people run them. I never did. Make sure you use the recommended restrictor for the turbo feed line. It varies friending upon turbo and some have one built in. Also use the recommended size feed line, usually a -3 or -4 and no bigger and the recommended size drain line, usually -8 or -10 or 1/2”. I prefer mounting the pump so it has standing on it’s head. That positions the feed line in at the lowest point. Make sure you get the correct flow direction through the pump — should be arrows but maybe some don’t have them.