I replaced the turbo oil lines and the oil cooler/oil filter housing gaskets in October 2023 (N14 engine). Since then the return line O ring that goes up into the turbo housing has leaked and needed to be replaced twice, in April and again today.

The lines I bought were OEM by Rein, as was the O ring in April. I've tried a Mahle O ring today: no leaks after a 10 km test drive. Hopefully it will last more than 5 months.

Has anyone else here had this problem before? Or a thought as to what's happening? The O rings have not been torn, but they are quite brittle and split when they come off the pipe.

 

rubber o-rings are a bad idea that close to a hot turbo. Do you have the heat little heat shield? That should help, but before it was available and my oil cooler started to leak, I upgraded to this braided stainless line: https://www.detroittuned.com/detroit...-oil-line-kit/

 

It's the return line that's leaking - the braided line in that kit is the oil supply line. The Detroit kit has the same return line that I've got, with an O ring in the turbo housing. I do have the heat shield on the supply line.

 

We made this kit to stop they o-ring oil line failure! https://www.detroittuned.com/detroit...ine-super-kit/ comes with everything you need and the option to ad oil cooler seals.

 

How is the oil return line (in particular the rubber O-ring) in the kit different? It looks like the stock one.

 

And the turbo oil return line o-ring has failed again :-(
Will replace it on Tuesday, but would like to know if anyone has a suggestion better than the OEM one made by Mahle.

 

I think there is an underlying issue going on. Not to judge your work or anything, but you're positive it is seated all the way in and flush before tightening the bolt down?
The only reason I ask is I had my original for 80k miles before I did the filter housing gaskets, braided feed line, and replaced the return line. The original never leaked. I've now got almost 100k miles on it and it isn't leaking yet. I've even replaced the turbo about 10k miles ago and reused the return line and it's perfectly fine. So I think that it is not going in properly before being tightened down. Or is it possible the turbo housing is warped or out of round in any way that it's just causing it to leak under pressure?

I believe I got the ECS recommended brand for the line. Can't remember the exact at this time

 

I've asked myself that too... I check with a "dentist mirror" that it's flush before tightening. Not sure what else to do to confirm it? I also wipe out the turbo housing before inserting the line to make sure there's nothing there that can interfere with the pipe fitting.

I did get the fitment wrong when I replaced the oil lines and filter housing gaskets in late 2023, and pinched and broke the o ring that came with the Rein oil return line I got from FCP Euro.

The o-rings are fairly hard and have had a split in them when I take the line out. It seems to me like they are made of the wrong material. Maybe I should get another new return line, but fitting the lower end was really hard to do.

UPDATE: have ordered a whole new return line.

 

I hope that it fixes it this time for good. I agree, it's a pain to install

 

It's 8 am Saturday morning here in Canberra, and I've got the pipe out. No sign of damage, or an obvious reason for it to be leaking, except for the o-ring having flattened sides.

I hope a new pipe assembly fixes the issue (or I'll see you back here in August).

Update: no leak after a test drive. I replaced the brake fluid too while the car was up off the ground, and it still stops :-)