Thread: Persistent turbo oil drain flange leak

Originally Posted by Eric SDV6SE

Dear Brains Trust,

I ve been battling a persistent oil drain flange leak on the passenger side turbo of my SDV6 SE for the past few days. Ordered new gaskets from the UK before Christmas with the plan to replace the one at the turbo over the last week. Leak has been “minor”, but drips onto the front driveshaft and is flung everywhere.

Replaced the old gasket last Thursday, refitted and torqued to specs (10Nm as I understand). Now leak is worse. Replaced again today with another gasket (ordered two just in case). Used Permatex Form-a-Gasket no.2 on the flange faces and Loctite 609 on the bolts. retorqued to spec and again after test drive an cool down. leak persists.

Any ideas?

thanks in advance

Dumb question. Are you *sure* that is where the leak actually originates (says he who dropped, rebuilt and reinstalled an entire transmission in the driveway to fix a leak that turned out to be a pinhole in a cooler pipe).

I stared under mine yesterday trying to find an (or one of many) oil leak/S. Much like Brad suggested, needle in a haystack.

Originally Posted by BradC

Dumb question. Are you *sure* that is where the leak actually originates (says he who dropped, rebuilt and reinstalled an entire transmission in the driveway to fix a leak that turned out to be a pinhole in a cooler pipe).

Good question Brad, AFAIK it’s from the flange, but could also be from where the flange meets the pipe. The top side of the turbo is clean and dry, so it’s not the supply oil pipe. When viewed from underneath, oil drips from the flange bolt furthest from the engine, I.e. wheel side, so I believe it’s leaking through the bolt hole in the flange.

will keep searching

Originally Posted by Eric SDV6SE

Good question Brad, AFAIK it’s from the flange, but could also be from where the flange meets the pipe. The top side of the turbo is clean and dry, so it’s not the supply oil pipe. When viewed from underneath, oil drips from the flange bolt furthest from the engine, I.e. wheel side, so I believe it’s leaking through the bolt hole in the flange.

will keep searching

The thing to consider is why? Why would it leak there? It’s not under pressure at that point (downside of the turbo bearing). Stating the obvious but capillary flow and motion/wind effect will cause it to move a lot. Anyway, you’re a capable chap so you know this. This is why I’m ignoring my leaks

I took a peek into this. Maybe consider getting some UV dye to trace it. For about $50 you can get a light and a small bottle of dye on eBay. Seems like a good way to find complex leaks

Originally Posted by Eric SDV6SE

Good question Brad, AFAIK it’s from the flange, but could also be from where the flange meets the pipe. The top side of the turbo is clean and dry, so it’s not the supply oil pipe. When viewed from underneath, oil drips from the flange bolt furthest from the engine, I.e. wheel side, so I believe it’s leaking through the bolt hole in the flange.

will keep searching

Hi Eric

My indie replaced my turbo drain pipe with the new/modified version during one of my services (wasn't leaking, but he did it as a preventative item before blocking/failure).
When I got home, it was leaking a little bit of oil.
I took it back to him and they spent quite a few hours searching for the source of the leak.

Turns out that there was a very small (hairline) crack in the flange that opened up slightly when it got hot - enough to let a little bit of oil out.

Not sure if that's common, but I thought they did really well to persevere and find it - as it was only happening when the engine warmed up...

Thanks.

Rob

Thanks Rob, I suspect mine's the same. Will investigate on Saturday..

Wouldn't happen to have a part number by any chance?.

OK, so I revisited this again. Cleaned everything down, retightened bolts to spec then ran the engine up to operating temperature in the garage. Still leaks.

Let it cool then torqued bolts up to 20Nm (double the spec). Bolts are 10.9 grade T30 torx, I wasn't worried so much about snapping the bolt, but rather stripping the thread in the turbo flange. Anyway, all good, no broken bolts etc.

Ran the engine up to temp again, thought I had it sorted, as at the same temperature no oil leaks. Refitted heat shields and went for a drive to get the turbo hot.

Result below:
20190112_140713.jpg

Still leaks....

Took it into LR yesterday for their advice and help. They replaced the existing drain pipe with a new one, plus double gasket on the turbo drain end.

Apparently the pipe and flange were OK, slight kink in pipe near the sump. Turbo flange also OK.

No more leaks, and all done at no cost.

Double thumbs up from me to my local LR dealer.