ruxtonmutt Posted March 31, 2018 Share Posted March 31, 2018 Blew the 2nd turbo. Coolant line had collapsed and starved the turbo of coolant. The line was inspected when I had the first turbo replaced about 3 years ago. When doing the coolant hose check is the expectation that you remove the turbo so you can inspect this hose? Thanks for any thoughts. Link to comment Share on other sites More sharing options...
mwiener2 Posted March 31, 2018 Share Posted March 31, 2018 Highly unlikely the turbo blew from a coolant line issue. My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
ruxtonmutt Posted March 31, 2018 Author Share Posted March 31, 2018 The coolant line was completely collapsed and no coolant was moving to cool the turbo, why don't you believe that would lead to the failure? This was the improved turbo from subaru which as I understand it has a larger hole in the union bolt and also a larger screen. I changed the oil and filter more frequently on the 2nd turbo than the 3750 miles. Though I don't drive the car very often so possibly I should follow the time interval ? I drove the car for 3 hours keeping the rpms below 2700 to get the car back to my mechanic, he seems to think it should be fine and that was his recommendation. I drove the car for a similar period on the first blown turbo and didn't experience any problems. Should I have any concerns outside of making sure any metal pieces that ended up in the oil pan are removed? Thanks for any thoughts / suggestions. Link to comment Share on other sites More sharing options...
mwiener2 Posted April 3, 2018 Share Posted April 3, 2018 Turbos don't need much cooling. You likely have an oiling problem or contaminated oil. It can be almost impossible to get all the bearing material out of the oil when a failure occurs, causing subsequent failures. Replace your oil cooler. It can trap material and it cannot be cleaned. If you read the spec sheets on many "water cooled" turbos, they state that the water cooling is optional. My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
ruxtonmutt Posted April 3, 2018 Author Share Posted April 3, 2018 I'll talk to my mechanic about the oil cooler. The mechanic was routinely checking the turbo filter screen and didn't find any obstructions on previous oil changes. Your theory would be that metal pieces remained in the oil/oil cooler and 3 years later released and clogged the turbo filter causing oil starvation, while the turbo also happened to have a collapsed coolant line? Thanks for the discussion, I am hoping to avoid getting a 3rd turbo in the future ! Turbos don't need much cooling. You likely have an oiling problem or contaminated oil. It can be almost impossible to get all the bearing material out of the oil when a failure occurs, causing subsequent failures. Replace your oil cooler. It can trap material and it cannot be cleaned. If you read the spec sheets on many "water cooled" turbos, they state that the water cooling is optional. Link to comment Share on other sites More sharing options...
mwiener2 Posted April 10, 2018 Share Posted April 10, 2018 The banjo bolt screens should be removed if they are ever serviced. It could take years for particulate to work it's way through the oil cooler. This is why it should always be replaced when there is a bearing failure. Failed cooling of the turbo would result in coking of the oil in the turbo bearing sections. if you are using a quality synthetic oil, it is very difficult to coke. If oil coking caused your turbo failure, you would have thick carbon deposits in the turbo center section and on the bearing surfaces. My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
ruxtonmutt Posted April 10, 2018 Author Share Posted April 10, 2018 You mean the screens should be permanently removed? I am not using a synthetic oil - would you recommend that I switch? The rebuilt turbo is installed and power seems to be good. It is still starting rough and my mechanic expects it to take a while before it starts smoothly as you say oil/etc was pushed through the fuel system and likely coked and will take some time to be completely flushed through. I'll talk to him about replacing the oil cooler as he didn't mention it. The banjo bolt screens should be removed if they are ever serviced. It could take years for particulate to work it's way through the oil cooler. This is why it should always be replaced when there is a bearing failure. Failed cooling of the turbo would result in coking of the oil in the turbo bearing sections. if you are using a quality synthetic oil, it is very difficult to coke. If oil coking caused your turbo failure, you would have thick carbon deposits in the turbo center section and on the bearing surfaces. Link to comment Share on other sites More sharing options...
mwiener2 Posted April 10, 2018 Share Posted April 10, 2018 You should be running only synthetic oil. The work performed on your car should not have touched the fuel system. It is completely separate from the oil system. It should take no more than 5 cold starts for the ECU to learn, so if it is continuing to run rough, there is another issue. Possibly intake or exhaust leaks. The screens should be removed permanently. My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
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