2013 50i exhaust leak under the hood... help?

[archival]

The 50i is out of warranty so problems seem to be coming fast and furious. Time to break out my wrenches again...

The newest issue is an exhaust leak under the hood. Exhaust is flowing from somewhere under the drivers side turbo under the hood. It started with just a whiff of exhaust that I couldn’t place, but now it’s coming out fast enough that I can see the puffs of smokey exhaust as the engine runs.

Pretty sure the exhaust manifold gasket blew out somewhere on the drivers side, but it might also be a gasket on the turbo to manifold, or turbo to catalytic converter. I’ve been in there before (fixing a turbo oil return leak), but it’s been awhile and I’m having a hard time figuring out what parts I’m going to need to buy to fix this.

So... I’m tearing everything out to get to the manifold (alternator, turbos). I’ve removed the manifolds before without removing the catalytic converter so I’ll just do the same this time. Should go easier this time around.

I know I’ll need two manifold gaskets, but I seem to remember that there’s a gasket between the big catalytic converter and the turbo (at the first brass-colored part in the back of the turbo was some kind of crush gasket), and there is a similar gasket between the turbo and the manifold. They’re gaskets that sit on the flat edge of the pipe, and get crushed when you put those weird circular belt clamps back on to reattach the turbo. I remember replacing those last time I was in there (I had to chisel the old ones out and shove new ones in).

Does anyone know the part numbers offhand for those things? I’ve been digging through parts websites for an hour and can’t figure it out. Just want to get all the parts I need up front so I can do the job right. This engine is a pain in the ass to open up and I don’t want to do it twice.

Help!

[archival]

Think I just found one of them...

BMW 11627576991 seems to be the manifold-to-turbo gasket. Now I need to find the one between the turbo and the catalytic converter.

[9vapors]

Originally Posted by archival

Think I just found one of them...

BMW 11627576991 seems to be the manifold-to-turbo gasket. Now I need to find the one between the turbo and the catalytic converter.

2 X Turbo to Downpipe Gasket Rings PN: 18307553601
2 X Downpipe to Front Pipe Gasket Rings: PN: 18307577959

[TKR]

While you are down there I recommend replacing turbo oil return lines (11427577010 & 11427577011) and return cover 11657577016. If they are not yet leaking they will start leaking soon, just like in every N63.

[Poppyboy]

Check out Chrisfix’s exhaust leak fixes on YouTube before you do anything else. He’s a genius.

[TwinSnailz]

Originally Posted by Poppyboy

Check out Chrisfix’s exhaust leak fixes on YouTube before you do anything else. He’s a genius.

lol nahhhh. Scotty Kilmer is the man.

[Ryan5034]

You should inspect the waste gate lever rods on the turbos, if they have too much play I believe exhaust will leak out of them as well.

Also consider you are supposed to replace the exhaust manifold nuts. they are part number 11627576992. Not sure why they can't be reused though. Check out this coolant hose as well, the plastic fitting will likely break off. 17127576363 Definitely replace the turbo oil cover and lines, you'll see why after you pull up the valley pan.

Good luck. Make sure you have a set of E-torx wrenches / sockets

[archival]

Originally Posted by TKR

While you are down there I recommend replacing turbo oil return lines (11427577010 & 11427577011) and return cover 11657577016. If they are not yet leaking they will start leaking soon, just like in every N63.

Yeah, way ahead of you on that. I was previously in there to replace the turbo oil return since it was leaking, and while I was at it, I replaced that stupid plastic y connection on the coolant lines under the turbo with a proper brass 3/8 t-junction. I had started leaking coolant and when I touched that y junction it literally broke into three pieces. I couldn’t believe what a POS it was.

I’ll say this - there is no way anyone is going to be able to avoid replacing that y junction. The material they make it out of is insanely weak against the heat it’s being subjected to. It’s possible to swap it without removing everything though... thankfully...

Sidenote - when removing the old y junction it left pieces inside the hoses. I used a big wood screw to remove them. Screwed it into the small hole of the nylon y that was broken off inside each of the three lines, then pulled it out. A brass y hose junction (3/8th size) was a few bucks at a true value hardware, and worked perfect as a replacement.

Anyway, it’s certainly a bit of a job pulling everything off. I’m not looking forward to doing it again . Got the gaskets. Going to get started. Hopefully I can figure out where this stupid thing is leaking exhaust and get it fixed. I’m about 95% sure it’s coming from the drivers side manifold right near the back. I’ll update once I’m done.

[Sophisticated Redneck]

I had the same problem, I did the recommended torque of 15nm and it came loose and caused a leak on the 1st and 4th cylinder on the Exhaust Manifold. Took it to 20nm this time on a digital just to be sure.

You should wrap your exhaust manifolds while you in there, I just did mine and DAMN what a difference it makes. Underhood temps are waaaaay down. (I just installed downpipes too and wrapped them so that made a big difference also. BMW should have done this from the start, insane having the manifolds in such a tight area with nothing to reflect back the heat, its why the turbo return lines get coked up.

I used 1" DEI Titanium wrap. Pretty easy to do but this wear a mask and googles if a do it, micro fibers float in the air when you do it. Stuff is really easy to work with and super soft and flexible unlike cheap fiberglass wrap

[TwinSnailz]

^how long did it took you to reach to reach the manifold removal ? Im starting to tear mine down tomorrow.

Also the torque specs for the manifold were 3 steps , 10, 15 and 20nm final.

[Sophisticated Redneck]

Originally Posted by TwinSnailz

^how long did it took you to reach to reach the manifold removal ? Im starting to tear mine down tomorrow.

Also the torque specs for the manifold were 3 steps , 10, 15 and 20nm final.

Hmmm, I thought it showed just 15 on newtis, well then it should hold this time lol.

It will take you about 3 hours to get to your first time. You have to pull the alternator to get to the sheilding screws that go to a heat sheilding that covers part of the manifold. The t30 screws holding mine were seized, I broke 3 bits getting them out....hopefully yours won't have the same fate...Remember that the black plastic wire conduit that goes over the alternator doesn't have to be taken apart (ignore the tabs on it) it actually will lift up and off the black metal brace that sits on top of the alternator. You will have to pull your fan and move the intercooler tank (just the top connections, you can leave the tank connected to the bottom and swing it out of the way)

[archival]

Ok, she's opened back up.

I threw some pressure on the exhaust and did the old spritz-soapy-water-on-it trick. Looks like bubbles coming off the gasket between the turbo and the manifold (under the driver side turbo).

I've also got air coming out of the passenger-size turbo lever.

I don't see ANY leaks coming off the manifold itself as far as I can tell, although I'm torn about leaving it. I'm considering just swapping the manifold gasket too since I'm down here already and I have a spare. I do NOT want to have to tear this thing down again.

So... questions...

How do you fix the air leaking out of the waste-gate lever on the passenger side turbo?

I don't actually see any way to remove or tighten up that lever. It looks like it's inserted with a literal metal pin holding it in. I see no way to disassemble that particular piece, and no way to seal it since it obviously needs to move.

That said... that particular leak was probably happening before I even started working on the car in the first place, and it's on the passenger side where I didn't see any smoke rising, so maybe internal pressure is helping keep it from pouring out exhaust? IDK...

Anyway, I screwed up and originally ordered the closest-to-turbo gasket instead of the one between the catalytic converter and the turbo, so I'm waiting on a gasket to show up before I bolt her all back together.

OH, as for the person who wants to know how long it takes to dig in here...

My steps (overly simplified):

Before you start... yank the negative battery cable off the battery. Otherwise you might get a rude awakening when you try to take the alternator off .

1: remove all the top-stuff (the engine cover, the bar that goes across the engine bay at the front, the plastic stuff at the very back above the engine, the two angled bars that connect the fender to the very back wall of the engine bay, and the cabin air filter).

2: remove the plastic air stuff that comes off the turbo - there are a couple air tubes that go to the front by the radiator you pull off first. Then you remove the two curved tubes that come off the bottom hole on the turbos, then you remove the top pieces that sit above the heat shroud.

You may have to open up the top tube going into the turbo and move that tube out of the way to do this - no need to fully detach the tube from the air cooler boxes, just detatch it from the turbo (be careful, there's a little rubber gasket in there that may fall out when you remove these things - be sure to catch it).

Also take note of several plugs that go into these things. You'll need to remove a round plug for each lower piece, and there's a plug on each upper piece too. Remove those first.

3: Remove the alternator.

This is a bit of a process. You'll need to remove the little secondary coolant bottle (the one that cools the turbos). That's going to make a mess, so put something under the car to catch all the coolant. You'll have to open up several hoses to do this, and if your car hasn't been torn down before, those hoses are going to be clamped with non-reusable hose clamps, so be prepared to replace a handful of small hose clamps with screw-clamps.

You'll also have to unscrew the turbo cooling pump from the alternator bracket and set it aside.

Before you mess with the alternator, remove the belt. That requires a BIG torx bit, which you're going to put into the tensioner and pull clockwise on a wrench. It helps if you've got a big wrench to do this. I used a breaker bar on a 1/2 inch driver.

Now CAREFULLY unbolt the four bolts that hold the alternator. There's a little plastic cable thing that goes above it (on top of the metal bracket the alternator sits in). You can actually pry that plastic piece up with a screwdriver (just insert it between the bracket and the plastic bridge, and carefully work it up and off). There are four screws holding the alternator down. Be careful because they're screwed into aluminum. You'll probably want to use some PB blaster on them and give them some time to loosen up before you crank them. And when you're putting it all back be SUPER careful not to mis-thread these things. Do NOT force those screws.

Anyway, there's a battery cable that needs to be removed on the back of the alternator (on the drivers side), and one little green plug stuck on top that you need to yank. Pull those, remove the 4 bolts holding the alternator down, and she'll slide right out.

There won't be room to fully remove the alternator if you haven't removed the fan, but, you CAN remove it fully if you remove the bracket. You'll have to take off two tiny bolts that are holding the fuel line to the bracket. Remove those, then pull the bracket out, and lift the alternator right out.

4: oxygen sensors etc

Next up you need to remove the head shroud. It's pretty self explanatory on how to do that. Remove the torx bolts and yank the shroud off the top. You'll need to remove the two top oxygen sensors first, so if you don't have an oxygen sensor socket... now's the time to get one. You will also need to yank some clips off the two side sensors to lift the shroud.

5: turbo time...

Get all of that off and you'll expose the turbos.

Now you've got access to the underside of the turbos. There are two little torx screws holding the turbos to the turbo oil return. You'll need to reach under them and unbolt both of those screws to eventually remove the turbos.

To remove the turbos themselves, you're going to need to remove the clamp-bolts holding them to the catalytic converter, and to the downpipe. You do NOT need to remove the clamp that holds the piece that connects to the downpipe - you can take that off as one piece connected to the turbo.

The hardest part is getting the manifold-to-turbo clamp off. There's not much room to get a wrench in there. I think I used a regular wrench to start it (moving it just a TINY bit at a time) until it was loose enough that I could kick the clamp loose and turn it enough that I could reach that bolt from between the two turbos from above with a socket-wrench. What a pain.

Now, before you can remove the turbos, you need to free them from the oil feed line. There is a bolt on top of this little funny looking round doughnut connected to the feed line that goes on both turbos. You'll see a line that goes down the side of the turbo and deep under the metal trays beneath. THAT is the feed line. When removing it, be super-careful because there's a washer under AND above the little round thing you're unscrewing. Catch both washers. You only need to remove one of these on each turbo.

Also make sure all hoses going to the turbos are removed in a way that allows you to remove the turbos. They're connected to all sorts of fun stuff, so be ready to detach several spots.

Once all that is done and the c-clamps are loosened, move them off their joint and carefully work the turbo off from the catalytic converter. It helps if you loosen the bolt holding the catalytic converter in place (there's a bolt on top connected to a bracket). Give that a little tug/wiggle, but be careful not to bend the turbo oil return line under the turbo. You DID unbolt that thing like I mentioned earlier, right?

That tube underneath has to be pulled more or less straight up, so just wiggle the turbo carefully until it lifts straight out. If you have any intention of re-using these turbo oil return lines, you do NOT want to bend them. that said, you should probably replace these things if you're already in here.

Repeat with the passenger side.

Now you've got a metal tray to remove and you're at the manifolds.

One thing to note - if you haven't removed the catalytic converters, you'll need to loosen them up in order to remove the drivers side manifold (it's REALLY tight at that back bolt and there isn't room to remove the manifold).

Remove the bolt holding the catalytic converter to the side, and remove the side O2 sensors so you have more wiggle room. The cats will move enough if you wiggle them to let you remove the manifold.

While you're down there, replace the y-junction the 3 coolant lines are plugged into under the turbo. I recommend going to a hardware shop and getting a 3-line brass t-junction in 3/8th size. I picked one up for a few bucks at a true value. The one that's in there WILL disintegrate and break into multiple pieces when you touch it. You'll need to use a wood screw to get the pieces of nylon y-joint out of the hoses.

Also replace the turbo oil return. It's cheap, and the gasket on it fails and pours oil down the center of your engine.

Be sure to wear eye protection, especially when removing coolant hoses.

Frankly, the first time you do this it's going to take you awhile. I spent the better part of a day getting everything torn down because I was being meticulous taking pictures and notes to myself, and labeling every screw I took off the engine.

The second time was much quicker. Probably 3 hours of effort since I knew what I was doing.

Officially, they'll say to remove the front cooling fan and the cats, but you can technically do this job without doing either of those things... so... you decide if you want to go the extra mile. It WOULD be much easier to yank the manifold and bolt it down nice and tight if you removed the cats. You're not getting a torque wrench in on the back-most manifold bolts without yanking the cats, so... use your discretion.

[Sophisticated Redneck]

Thats your wastegates the lever is attached too, it's normal to have some very light leakage as it can't be super tight since it is made to rotate at temps well over 800 degrees. If they are really worn out though it will cause a loss of performance as they won't close properly. The rebuild kit is only about 80 dollars but it's absolute bitch to do. It requires a welder and hydraulic press...not for everyone. I just did mine and it sucked. New turbos from BMW are only 545.00 each, if I could go back in time I would just by new

[archival]

Done and fixed. Spent a lot more time carefully cleaning the intake and manifold with a plastic scrape tool and acetone. Had it shining like a mirror before I bolted it back together with new gaskets on the manifold and the turbos (one below where they connect to the manifolds and one at the catalytic converter). No more exhaust leak.

Definitely was the manifold gasket. My own fault really. I suspect I didn’t torque the backmost bolt down tight enough last time I was in there doing the turbo oil gasket and the stupid leaking plastic y joint coolant lines under the turbo. A tiny exhaust leak became a big one and the rest is history.

Anyway... with those “minor” (read: bmw wants 3k-4k to replace a leaking turbo oil return- lol) issues handled, now I pray to the bmw gods that I don’t end up needing valve seals anytime soon. It was nice to get behind the wheel and put it through its paces. I have such a damn love hate relationship with this x5.

[9vapors]

I feel the same, glad you got it fixed!