Oil return line is leaking

[Fonsi]

Hi guys,

my BNR S1 is leaking oil at the oil return line underneath the turbo. Two months after installing the S1, it looked like this:



I cleaned everything up and installed a new upper gasket at the oil return line (when installign the BNR S1, I re-used the old gasket). It seems that there is now less oil leaking but it still leaks somewhere underneath.

Any help or hints appreciated. According to my Mazda dealer you dont have to use any kind of sealant for the screws.

[wyeto]

I hate oil leaks man. Its so hard to get rid of them, it seems like your always checking under the car for oil.

The dealer was right you don't use sealant on the screws it gets too hot for any sealant.

If it is still leaking but just less I would go out to your car when it is cold in the morning and feel the oil feed line on top of the turbo. See if there's any oil on your hand. If not start the car and feel the line again. You may have a slight leak from where the banjo bolt crush washers are on the feed line and it could be dripping down to the return line.

[Fonsi]

Originally Posted by wyeto You may have a slight leak from where the banjo bolt crush washers are on the feed line and it could be dripping down to the return line.

Good idea dude. I'll install new banjo bolt crush washers and see if it helps.

[wyeto]

Originally Posted by Fonsi Good idea dude. I'll install new banjo bolt crush washers and see if it helps.

Those crush washers really can be a pain in the ass. Its really tempting to re-use them but they just don't seal up the same.

Before you reinstall I would do that test to confirm that's where its leaking. Put your hand straight on that banjo bolt where those washers are and go all the way around then see if there's oil on your fingers.

[Fonsi]

I'll to that test first, thanks!

[Code Monkey]

If it is not the feed line as stated above, take the oil drain line off and see if there are any cracks in it. In it was the flex section, but you have a leak coming from way above so I hope this is the feed line. Is the oil leaking at idle or only after you put some load on the engine?

[wyeto]

Originally Posted by Code Monkey If it is not the feed line as stated above, take the oil drain line off and see if there are any cracks in it. In it was the flex section, but you have a leak coming from way above so I hope this is the feed line. Is the oil leaking at idle or only after you put some load on the engine?

This is a hard test to get results from unless its leaking really bad haha.

I was going to add make sure to check the feed and return for cracks because if they are cracked it can get REALLY ugly fast.

I had my feed line break on my vw tdi daily commuter and I was lucky enough to be pulling into a parking spot at the time. It takes 4.5 qts when you do an oil change and after I installed the new line I had to fill up just over 4 qts... talk about a lucky close call. The line had been leaking pretty good for a while and I just got lucky I wasn't on the freeway or driving around when it broke.

[Fonsi]

Alright, I'll check the feed and return line for cracks and will replace the crush washers on the feed line the upcoming week.

I cannot exactly say if its in idle or under pressure. What I can say is that it seems to be a very slow leak, as there are now 4 weeks gone since I replaced the gasked and cleaned everything up and there was just little oil at the return line yesterday.

[MD1032]

I'm in the same boat with my S3. Included gasket was junk. Put a spare OE on, but I think it's still leaking a little bit. Wish I had just installed new crush washers and OEM gaskets on the feed and drain lines when I put the turbo in. What a pain in the ass.

[Fonsi]

I've checked the inlet pipe and the compressor housing yesterday. Apart from two or three little drops of oil it is bone try in there.

I'm checking the oil feed line the day after tomorrow. I've already purchased new crush washers to replace the old ones. I hope this helps .

[Fonsi]

Checked the oil feed line today and found these two crush washers around the banjo bolt:



100 points for the one who can see the difference

[Code Monkey]

No difference, both would fit on my dick.

[Fonsi]

Originally Posted by Code Monkey No difference, both would fit on my dick.

This answer is worth 100 points too

[wyeto]

Weird. I think you found your leak.

[Fonsi]

I hope so. These crush washers came with my BNR S1.

I dont know if the larger one was meant to fit the coolant line and I was just too dumb to compare them or anything else... I replaced them with two new OEM ones for fck*n 4 dollars to make sure they'll fit now.

[cyclist20]

Originally Posted by Fonsi I hope so. These crush washers came with my BNR S1. I dont know if the larger one was meant to fit the coolant line and I was just too dumb to compare them or anything else... I replaced them with two new OEM ones for fck*n 4 dollars to make sure they'll fit now.

Yes, from what I recall the coolant washers were bigger. I suspect you will be good to go.

[Fonsi]

Unfortunately, changing the oil feed line crush washers did not help.

I still think it might be the return line / gasket but I already replaced the oil return line gasket. There is even oil around the screws .

Pictures from today:







I cleaned everything up and wrapped two gaskets around the upper return line and torqued it down.
Any ideas?

[wyeto]

Damn man that sucks! I'd say clean everything and when you attach the upper gasket go in really evenly with the bolts. Once they are snug tq down in increments.

If I remember correctly they are 13ft/lbs is that right?

I don't think 2 gaskets on the upper oil return line is gonna help. Usually doubling up on gaskets hurts things not helps.

[Code Monkey]

^ What he said, just use one gasket, maybe smear a dab of RTV on it.

[Fonsi]

The workshop manual says 8-10nm which is around 5.9-7.4 ft lbs.

Cleaning and attaching the gasket is what I did first.
Then I replaced the upper gasket with a new OEM one.

Its still leaking ... thats why I tried the two gaskets now

Originally Posted by Code Monkey ^ What he said, just use one gasket, maybe smear a dab of RTV on it.

RTV between the gasket and the turbo? Or between the gasket and the return line?

[wyeto]

Ok well no harm in trying, but if you've ever done an oil change and one o-ring gasket gets stuck and you put another filter on you would know 2 gaskets won't be better than one.

I wouldn't suggest rtv because the turbos get so hot I think it would probably burn/smolder and you'd regret it...
Maybe copper spray? Idk man

I guess if you can't get the leak to stop check for cracks where it could be coming from.

I was way off with those tq specs

[Code Monkey]

Yeah, copper spray should work, spray both sides of the gasket.

[dale_gribble]

Man, careful crusing that thing around. That oil is pretty volatile, is right above the exhaust and will catch on fire. Ask me how I know.

[Fonsi]

I'll try some copper paste. Thank you guys!

[cyclist20]

I'm wondering if it is the weld at the flange. the oil does not appear to be much on the turbo and mostly only on the return line/flange. Perhaps that is cracked? Is it possible they tapped the threads to deep? If that is the case the no gaskets would make a difference.

[Fonsi]

I took a closer look at the oil return line and could not find any cracks. But that is the next part to be replaced after I tried the copper spray.

I'll check the threads of the screws too. But its hard to have a look underneath the car without taking the whole turbo out :-(.

I'm wondering about the oil at the screws... I still think the gasket is not 100% ok. I dont know :-/.

[Code Monkey]

Pressurize the line like I did in the video above; although seeing where the leak is coming from I doubt it is the line.

[Fonsi]

Originally Posted by Code Monkey Pressurize the line like I did in the video above; although seeing where the leak is coming from I doubt it is the line.

Yeah, I will test that after trying the copper spray.
At least I hope its some kind of gasket / return line leak. If its the turbo, I'm having a huge problem

[dale_gribble]

Make sure the surfaces are SPOTLESS, or the oil won't let things setup properly.

[Fonsi]

Good news ... well, at least until today. The oil return line is bone dry. It seems the two gaskets are working . It hope it stays dry...

[wyeto]

Right on! Any update of the last few days?

[Fonsi]

Originally Posted by wyeto Right on! Any update of the last few days?

Not yet dude. I'm off during christmas and new year's eve, so I don't drive that much. But I'll keep you guys up to date .

[wyeto]

Sounds good man. I'm really interested to hear how the double gasket works.

[aviator79]

Maybe the holes were not drilled or tapped deep enough and the bolts were bottoming out and the thicker two gaskets made up for that? Need to test remove drain and see if bolt goes all the way in past thickness of drain flange. If just not drilled deem enough can just grind end of bolt down or if not tapped far enough need shorter bolt. But looks good now anyways...just seems weird.

[blackms3_71]

Originally Posted by aviator79 Maybe the holes were not drilled or tapped deep enough and the bolts were bottoming out and the thicker two gaskets made up for that? Need to test remove drain and see if bolt goes all the way in past thickness of drain flange. If just not drilled deem enough can just grind end of bolt down or if not tapped far enough need shorter bolt. But looks good now anyways...just seems weird.

Yeah 2 gaskets in place of one usually never works but with the cooper spray he seemed to get lucky

[Fonsi]

Its still bone try underneath the turbo. Last weekend I was for about 200km on the german autobahn. I guess my double gasket patent works

[wyeto]

I think that copper spray did the trick but either way your sailing now!

[Fonsi]

There is no copper spray on the gaskets . That would have been my next step if the double gaskets are not working...

[wyeto]

That is seriously weird my friend haha. Well right on man good stuff.

[MD1032]

Probably just shitty tolerances on the BNR or oil drain line itself (or both). Mine's leaking right now and I bought new gaskets from Mazda. Hopefully that will fix the problem. If not, maybe I'll order some more and double them up like you suggested.