There is a leak coming from the connection of the turbocharger oil supply line to the engine.

I want to know what I am getting into if I try to re-seat the supply line to the engine block? It appears that the supply line is not going straight into the fitting that goes into the engine block. See the attached picture.

Is there an O-ring that makes the seal between the supply line to the engine block or is it a metal-to-metal seal?

If I need to replace the entire supply line what are the minimum steps I have to take to replace it? Is there a link on this Forum that will help?

The car is a cherry 1991 350SD with 90K miles and 35K on a rebuilt engine with updated rods. This appears to be the only oil leak and I want to fix it. I am especially concerned that the line could just "blow" and kill the engine and turbo.

Attached Thumbnails

 

__________________
1991 350SD (updated rods)
Biodiesel B100 when I can find it.
Dino when really cold outside

oh yuck!
I am changing one on my car now. But completely differant.
Good luck! And I am sure someone will be along to help!

__________________
83 300SD Dark Silver Dark brown inside

Are you changing this on your 300SD? Isn't it the same?

P.S. I'm from Seattle but living in Virginia.

__________________
1991 350SD (updated rods)
Biodiesel B100 when I can find it.
Dino when really cold outside

There's no o-ring. The oil feed line fitting into the block is like a brake line into a caliper, only a lot bigger. You can release and try to reseat the fitting. If it has to be replaced, it's not too difficult. All you need besides a new line is the gasket at the turbo end. There are two tricky steps. The worse of the two is getting to the bolt that holds a clamp along the feed line so somewhere near the engine mount arm. The clamp bolt on the SDL was hell to remove, impossible to refit. Maybe you'll be luckier. The other is snaking the new line into place without removing the manifold. The key is to note how the old one was routed.

Sixto
87 300D

Does anyone know how long this should take at a shop? It would be good to know the ballpark estimate before taking it in.

__________________
1991 350SD (updated rods)
Biodiesel B100 when I can find it.
Dino when really cold outside

I've done in an hour so I don't expect to see more than two billable hours.

Sixto
87 300D

I just tried re-seating the fitting on the engine side of the turbo oil feed line and it didn't help.

I am going to order the new line and gasket tomorrow.

Would anyone besides Mercedes have a new line?

__________________
1991 350SD (updated rods)
Biodiesel B100 when I can find it.
Dino when really cold outside

Thanks everyone for your help with this project. I started and completed it yesterday and the tips I received here were a big help. I decided to give back my experience.

A picture of the bad turbo supply line is attached. I am not sure how this damage happened as it would be difficult to do this without some abuse. It took about 4 hours but I am not a pro and there were a couple of things that slowed me down.

The under-engine cover needs to be removed to get at the connection to the block and mounting bracket.

The supply line to the engine block is metal-to-metal. A 17 mm open-end wrench can be used to loosen it. A small amount of oil will come out so be prepared with some rags.

Disconnect the 10 mm bolt, accessible from underneath the car that secures the line to the forward most turbo mounting bracket. A 10 mm short socket and ratchet can be used to remove it.

There are two 6 mm Allen head bolts attaching the line to the turbo's center section. The bolts are almost impossible to reach with a standard 6mm Allen wrench or ball driver. See the attached picture. There is a thin fiber gasket between this fitting and the turbo's center section.

A single 6mm Allen wrench (Fastenal $0.94) was cut-off at the L section for a tool to remove the Allen bolts. Tape, a 6mm socket, two extensions, and a ratchet, were used to drive the cut-off Allen wrench. See attached picture.

To attach the new turbo supply line, first stick the new gasket to the turbo with some heavy oil, e.g. HiTack. Snake the supply like into place from below and hand-tighten the connection to the engine block.

Adjust the gasket as needed with a long tool and drop the hex bolts back into the connection to the turbo with some needle nose pliers and gently tighten with the special too.

Re-attach and tighten the mounting bracket with the 10mm bolt. A long screw driver can be used to slightly flex the supply line so the bracket lines up to the bolt.

Tighten the connection to the engine block with a 17mm open-end wrench.

Tighten the hex bolts on the turbo side with the special tool.

COMPLIACTIONS:

Cleaning the under engine covers takes time.

The turbo supply line was stuck to the turbo and needed to be pried-off with a screwdriver.
Remnants of the gasket stuck to the turbo (probably not oiled when assembled). It was very difficult to remove the remaining gasket with flat razor knife. Some remaining pieces were scraped off with a dental-tool-like scraper. A couple of gasket pieces fell into the turbo oil inlet and had to be sucked (LiquiVac)/picked out.

Aligning the gasket is not easy in such a tight space.

The oil line is only available from Mercedes and is expensive.

Attached Thumbnails

     

__________________
1991 350SD (updated rods)
Biodiesel B100 when I can find it.
Dino when really cold outside