BMW 328i xDrive Valve Cover Leak

[JGaulard]

Not long ago, I began noticing a distinct burning odor each time I started my 2009 BMW 328xi. Given that it was the middle of winter, I routinely had the interior blower running at full force, trying to coax some much-needed warmth into the cabin. It was during these moments that the smell became most pronounced - thick, acrid, and impossible to ignore. At other times, particularly when making a sharp left turn or braking abruptly, a different but equally unpleasant odor would creep in - something foul and unmistakably wrong. Sitting at a stoplight, trapped in the enclosed space of the car, I found myself forced to endure the lingering stench, wondering what exactly was going on beneath the hood.

After a bit of investigation, the culprit revealed itself: a leaking valve cover. Engine oil was seeping out and dripping down onto the exhaust manifold, where it would burn off and produce that unmistakable smell. As it turns out, this is a fairly common issue with BMWs, especially as they accumulate mileage and age. What makes matters worse is that this isn’t a simple gasket replacement job. Due to years of repeated heating and cooling cycles, the plastic valve cover itself tends to become brittle and warped over time. Because of this, replacing just the gasket is often not sufficient - the entire valve cover assembly needs to be swapped out.

With that in mind, I went ahead and ordered a new valve cover, which conveniently includes a complete gasket kit, from FCP Euro. The total cost came to $235, which seems reasonable considering the scope of the repair. The part is listed under SKU MAH-ZH21 and is manufactured by Mahle, a brand with a solid reputation for quality components.

From everything I’ve read and watched, this repair appears to be well within reach for someone who is reasonably handy with tools and has a bit of mechanical intuition. I’d like to think I fit that description, so I plan to tackle the job myself. I’ll be sure to document the process and provide updates as I move forward with replacing the valve cover.

 

[JGaulard]

Big day today - huge, actually. The valve cover and gasket kit arrived yesterday, and I decided to try removing the cover today. At first, I planned to just take it off to see how long it would take, but I ended up going all the way and replacing it.

I can now report that it’s a beast of a job. What made it so time-consuming and complicated was simply the fact that I’d never done anything like it before. Now that I’ve gone through it once, I’m confident I could do it in half the time next time. It’s definitely a job an amateur can tackle, and no specialized tools are required - Torx sockets are about as exotic as it gets.

I relied on three videos for this project, which I’ll share below. I also took some photos along the way and will include those as well. I’m not quite finished yet - I ran into a snag with a ground cable that needs replacing - but I’m hoping to get that sorted out soon and wrap things up.

For now, here are the videos I used to learn what I needed to do:

And here are some photos with descriptions.



In the above photo, I already removed the big plastic cover that sat above the valve cover.





In the two above photos. I pulled out the coils and unattached some of the electrical.



And now I've held aside the electrical with some bungee cords. This is critical. You'll need to do this to keep the many very annoying electrical components and wires held to the side. You'll go crazy if you allow them to hang.

 

[JGaulard]

The real issue with tackling a project like this is that a person has no idea what to remove and how to go about removing what needs removal. The videos post above are essential. Also, if you have questions, feel free to post below and I can help.

These two photos show the head with the valve cover removed. My advice would be to get as much stuff out of the way as you can. Don't think you can sneak the cover by without removing something. You can't. You need to get it all out of the way. And there's a lot of items to remove. Again, it's a bear.





This is the inside of the old valve cover. I'm sure I could have gotten away with using the old cover because it seemed fine. The gaskets were old, hard, and cracking though. But I got a new cover anyway, just to play it safe.



And this is the new cover. Looks just like the old one. It came with all the necessary gaskets.

 

[JGaulard]

Finally, I was able to fit the new cover back on. This took a while because I did it alone and everything seemed to be in the way. It's just a tough job, but I did it. Here are some photos of that.





During the fitment, I noticed that the ground cable was broken. I had to remove the old one on one side via a nut and then I had to drill a hole for the other side. I tried to remove the nut on that side and it just fell apart because of rust. Below is a photo of the new ground post.



And finally, a very pretty picture of the head without of the valve cover. It looks cool, so I snapped a picture of it.



I'll keep updating this thread as I go and take more pictures.