anyone ver have a scavenge turbo oil pump fail?

[jryerson]

after a valve job engine teardown the turbo scavenge pump seems to not be pumping or working at all, getting oil in my exhaust and it leaking around the turbo, the breather hose from the turbo oil tank is returning oil back into the oil tank which shouldn't be happening as well thus building pressure in the oil tank also. My mechanic has tested the scavenge pump by taking the line from the oil tank on the turbo off and filling a container full of oil to verify its not working, a mechanic that screwed up my car before never put the ball bearing that restricts flow in the banjo for the turbo oil supply so it was dousing the turbo with oil and probably caused cavitation and maybe killed the scavenge pump.

My mechanic also tried to prime the scavenge pump to no success, anyone ever have one fail? they seem very robust as a gear oil pump so doesn't make sense car only has around 70k orig miles on it

Thanks in advance

[Jim2]

Take the pump off and inspect the drive bolts on the face of the toothed pulley. they may not have enough length to engage the pump. One of mine was only engaging by a few thou of an inch, it was only time until it started to skip.

I also had the engine tin abraid through the brass tube leading to the scavenge pump. This happened near the wastegate where there is a seam in the engine tin. The hole in the tube allowed the scavenge pump to draw air and oil backed up in the turbo an came out the both the compressor and trubine.

[rsrmike]

I've had a small foreign object find it's way from a rebuilt turbo, into the turbo sump, and ultimately wound up at the scavenge pump where it locked the 2 gears and sheared the drive pin. It also slightly gouged the pump housing.

I pulled the pump apart, cleaned it up, polished the housing up a little, and fabricated a new drive pin from medical grade titanium used to make dental implants. It works fine now

[jryerson]

Thanks I'll have him pull it so we can inspect it, ordered a used one in the meantime