I have experienced this with a different Volvo Penta motor D3 220 hp. The D3 has a different Turbo but bearing and seal are of a similar design. The Issue that I experienced slightly different. My original issue was not oil leaking from the weep hole at the after cooler. (D3 aftercooler has a drain plug to drain condensation not a weep hole) The issue for me was elevated intake air temperatures damaged the hose between the turbo and aftercooler. This damage softened the silicon rubber hose and it started leaking oil. I had oil blown covering the block and in the bilge.Probably no more than a cup of oil but a cup of diesel black oil makes a mess.
Where was the oil coming from? Damaged seal and bearing? I had a Volvo technician inspect the Turbo, hose damage and evaluate the issue. He diagnosed a failed turbo that caused the hose to fail. His inspection of the bearing was checking the compressor side of the turbo impeller side play deeming it to excessive play. What is excessive play? I could not get that answer from Volvo. This happened at 400 hrs. I am the original owner and have maintained the engine based on Volvo'e service recommendations. The boat does set idle from November to May each.
I had extended warranty on the engine and Volvo paid to replace the Turbo, hose, pressure check and clean the after cooler.
Repair findings- The after cooler had saturation of oil in it, The transition hose between the Turbo and Aftercooler was destroyed.
Turbo after removing and inspecting showed minimal movement but we could not get a spec from Volvo. Our source of spec was comparing side play of the new to install turbo with removed turbo. The old turbo had less play the the new turbo?
Old turbo photo after removal
The after cooler showed evidence of oil saturation it was pressure checked (Ok) The after cooler was cleaned.
Assembly of all components was a success . I did change the OEM hose clamps to a better design clamp to help hold the hose in place. the clamp design is made to keep a constant clamping force when intake temperatures increase allowing for expansion and contraction. I also installed a ventilation system, After this accident I increased incoming air and out going air from the engine compartment to help keep intake air temperature down to recommended levels.
New style hoes clamps
New Turbo that was installed with slightly more side play compared to old turbo. This photo was taken after 5 hours of operation and showed evidence of oil. The thin lines in the throat of the turbo is oil.
The turbo used is a Garrett Turbo. I was not able to receive any information from Volvo so I went right to the manufacturer of the Turbo. Explanation I received from Garrett is the side play inspection needs to be done evenly using even pressure turbine side wheel and compressor side wheel moving the shaft side to side. If the inspection is done on only one side this amplifies the movement and will seem to be excessive movement. ( this was the way the Volvo technician inspected the turbo). When inspecting the turbo if the bearing sleeve is damaged it is obvious. The seals in the turbo are not positive there is alway going to be some leakage. There is a small amount of leakage if operating at low rpm because there is no boost pressure but there is oil pressure at the bearings this allows some oil to seep by the seals.
Another area that oil can get into the Turbo is from the engine ventilation system. There is a catch can filter that catches blow by and separates the oil and returns this to the crank case. There is still some oil carry over that can enter the turbo. If the catch can filter is not changed, dirty and saturated the carry over is greater the result is oil in the aftercooler and intake. The danger of to much carry over is the engine can run on oil. A damaged oil seal leaking extensively can cause a runaway.
Before replacing the turbo, confirm that the proper inspections are done and don't over look the crank case ventilation filter and engine blow by. A badly damaged bearing and seal should show evidence of soot and some smoke at the exhaust. Also inspect the outside are of the turbo for external leaks. In my case I received a new turbo under warranty at no cost to me. I can't complain. I question if the replacement was needed after the total troubleshoot. Volvo ok'ed it. I went with it. I know what I will do in the future if this issue happens again.
