7/8th Inch Oil Drain Line

One annoying thing about The Dog since i started going turbo was the occasional smoke from exhaust. I've tried restricting the oil supply line with custom banjo nipple bolt, installing an oil catch tank and connecting it to the turbo inlet in hopes to reduce some crankcase pressure and replacing the oil drain flange on the sump with bigger pipe with no significant success. Those steps have managed to eliminate the smoke during deceleration but that's it. Most annoying smoke problem is during idling after the engine has warmed up such as traffic light stop. I had to blip the throttle every few seconds to avoid having white thick smoke coming out from the exhaust. No fun for sure.

One last thing i could do before blaming the turbo oil seals is to enlarge the drain line and that was what i did today. My drain line initially was 5/8 inch (~16mm) and i decided to try with 7/8 (~23mm). Since finding a stainless steel braided hose with such diameter is nearly impossible in this small town of Bandar Lampung, a radiator hose was chosen as an alternative. Here's a comparison shot, left is my old steel braided line and the other is the 7/8th ID radiator hose.

I also decided to ditch the oil sump drain flange and weld the drain pipe directly to the sump. No particular reason, just because.

Here's the finished work.

Yes, that looks dangerously close to the exhaust manifold. We'll see if that radiator hose sans stainless steel braids would handle the heat.

Probably too early to tell, but after it's done, i let the car idled for 15 minutes, drove for another 15 and not a hint of smoke can be seen from the exhaust even during idling. Fingers crossed!