[martinpetrov1096]

TLDR:
The following, and then have some questions at the bottom of this post
Also, here’s an album of the photos I took:
- Started smelling a fairly strong smell of what I am 90% sure is burning oil
- Smell got worse pretty quick, started seeing smoke near where the turbos sit
- Am broke, so decided to try and fix it myself
- Took off small turbo
- There’s definitely a good amount of oil inside turbo on intake side
- Found oil everywhere, pretty much impossible to actually pinpoint any single leak
- Seems like there’s a good amount of coating on the engine block itself. What could possibly cause this?
- Is it the engine cover gasket?
- Noticed that the bolts connecting exhaust and EGR cooler were completely loose
- Was wondering if this could be what I was smelling, and not an oil leak??

Hey guys,
I’ve been a pretty noob mechanic for a while now, and I (along with my wallet) finally decided to get my hands dirty. Hopefully there’s a forum guru with a 335D that can help me out.

Basically, I started smelling a strong scent of what I’m pretty certain was burning oil (though I’ll go into later why I kinda now have my doubts). Additionally, I started to see smoke coming from where the turbos sit. This definitely spooked me quite a bit since I’m assuming that oil and hot turbos can cause a fire pretty quickly.

So, I decided to actually try and fix it myself. Just looking at everything, it was really hard to tell where the source of any leak was coming from. The car is at 120k miles, and has been taken apart a dozen times by frustrated mechanics that are short on time. As such, it seems like no one has ever bothered to try and clean up old leaks that they fixed. And because of that, it’s almost impossible for me to really know what leak is new, and which one is old.

Since I didn’t see anything obvious, I ended up taking the small turbo off the car. After doing this, I noticed that the EGR cooler had a bolt completely loose. This got me thinking, could I have actually been smelling exhaust gases rather than burning oil? Is there any way I could confirm/deny this theory?

Also, I didn’t really find any obvious sources of oil leaks. The weirdest thing I noticed was that the engine block itself seemed to be covered in oil that seemed to be more fresh than in other places. The exact location is to the right of the turbos, right below the plastic. Is it the valve cover gasket?

The turbos themselves seem to be covered in oil on the outside from the intake side. From what I’ve read, some oil is to be expected, though excessive oil is a sign to replace the turbos. Now, to me it does seem quite excessive, though I don’t trust my own judgement to spend 2k on them, so if anyone else can give me a confirmation on that, that’d be great. There’s photos in the album I linked at the top, as well as a video showing the shaft play. Should note, there is no play back and forth, only side to side. I also have heard that there should be some play without any oil in them, but am not sure exactly how much is acceptable.

Questions
- Why is the engine block coated with oil?
- There’s photos in the album
- Is it the valve cover gasket?
- Are the turbos blown?
- Video showing how much shaft play there is in the album
- Should I buy new ones or send these to be rebuilt?
- What parts should I replace when I’m already here?

[Yozh]

How’s the driveability? You do need to replace the gasket for the fresh air pipe to large turbo inlet. Easy and cheap. Fix your EGR cooler connection. Leaks there will smell raw exhaust.

[335dlci]

A bad vcg will cause turbo failure

[BB_cuda]

i would have cleaned with degreaser real good before taking apart. Then run and see fresh oil coming from, hopefully one of those places and repair it. You basically destroyed a way to diagnose your problem by taking it all apart. I agree with Yozh to check the large gland seal at large turbo inlet. I changed it on one of our M57s and have another for when that area it taken apart on second M57. Likely when i do the vacuum lines on it.

[KASHe91]

Originally Posted by Yozh

How’s the driveability? You do need to replace the gasket for the fresh air pipe to large turbo inlet. Easy and cheap. Fix your EGR cooler connection. Leaks there will smell raw exhaust.

Originally Posted by Yozh

How’s the driveability? You do need to replace the gasket for the fresh air pipe to large turbo inlet. Easy and cheap. Fix your EGR cooler connection. Leaks there will smell raw exhaust.

would you be able to explain more on EGR cooler connection. As think I got strong exhaust smell.. Is it the connection to the exhaust manifold? And how would you fix it?

Cheers

[daniel35d]

Originally Posted by 335dlci

A bad vcg will cause turbo failure

How so? And which one, or both?

[daniel35d]

From what I've been told by other M57 335d owners, several have experienced bolt(s) for the exhaust manifold backing out. The ones that mounts it to the block AND the ones that mounts the EGR cooler to the manifold.

Some have also experienced the flexipipe part of the EGR cooler that goes to the exhaust manifold cracking, so that's also something you could check out.

Mine is at 111k miles and seem to have a small leak from the VCG, so I do have a bit of a burning smell every now and then. The oil leaks down on the manifold.

There is also oil lines for the turbos that can leak, and the line that returns oil back to the oilpan. This one has a gasket that can go bad AFAIK.

[martinpetrov1096]

Originally Posted by Yozh

How’s the driveability? You do need to replace the gasket for the fresh air pipe to large turbo inlet. Easy and cheap. Fix your EGR cooler connection. Leaks there will smell raw exhaust.

Honestly the drivability was totally fine. I did go to a place that rebuilds turbos and they did say I needed to replace it. Honestly for $500, a new turbo is cheaper than expected and while I'm not 100% this one is completely done, the amount of oil on it, and the amount of play in the shaft definitely seems like its on its way out anyways.

[martinpetrov1096]

Originally Posted by BB_cuda

i would have cleaned with degreaser real good before taking apart. Then run and see fresh oil coming from, hopefully one of those places and repair it. You basically destroyed a way to diagnose your problem by taking it all apart. I agree with Yozh to check the large gland seal at large turbo inlet. I changed it on one of our M57s and have another for when that area it taken apart on second M57. Likely when i do the vacuum lines on it.

Ya, in retrospect this would've been quite wise. Though also I'm not sure how much success I would've had degreasing it without it being taken apart. Looking at it now, I'm almost certain that the freshest leak I had was the valve cover gasket. There was still wet oil on the engine block that I couldn't really see without taking the small turbo out.

Thanks for the advice on the gland seal though, I'll definitely look into buying a replacement for that.