So I have this older Komatsu and it’s been running good for years until this summer. When I start it I have blue smoke at low idles and oil leaking through the turbo into the exhaust system. I changed out the Turbo thinking that was the issue but didn’t solve anything, Also I noticed that when I take off the oil filler cap there is quite a bit of pressure but when you remove it it’s not blowing by like blow by just pressure. My next step is to see if the oil drain from the turbo back to the oil pan is plugged and to see if the crank case vent is plugged. If you have any other suggestions I’d sure appreciate it!
That's an old dog for sure. How many hours do you have on the clock? Sounds like ring and piston problems to me. The blue smoke at cold start was kinda normal. The oil in the exhaust and the high blow by indicate it's time to take a look inside.
Problem Solved! The oil return wasn’t plugged but wasn’t free flowing either so I cleaned that out but the major issue was the vent from the valve cover back to the crank case was plugged. I took it all apart cleaned it and the old girl is running cleaner then ever!