There is a history of diesels having injector issues (cylinders 5 and 6) related to water causing corrosion on them. The problem is elledged to start from water leak at the center cowl. There is foam underneath the engine cover that holds the water there. I'm told the 2013 year corrected the design to where the center partition no longer cracks. The older models typically crack allowing water flow in. Some people remove the foam to not allow the water to stay there if it comes. I haven't experienced this on our 2013 but we have only had the X for 6 months. I've had same M57 diesel engine in 3 series for nearly 7 years.

I've never sprayed water under the hood. I use a little bit engine cleaner spray and wipe with paper towels. I do appreciate the need to keep it somewhat tidy under the hood to help quickly identify if a boost leak has cropped up.

For my E70, since it was neglected and came with lots of oil/dirt/grime build up all over the place from various oil leaks (fixed now), some of which was very thick, I used Gunk Engine Cleaner & Degreaser Part No. EBT32 and and air powered cleaning gun. I've used many other products, but personally like Gunk.

Air gun: https://www.amazon.com/gp/product/B00ELDY936/ref=od_aui_detailpages00?ie=UTF8&psc=1

The gun allowed me to get into a lot of places a simple hose (not enough pressure or too much 'splash' effect) or pressure washer (too much pressure) wouldn't be good options. This gun let's me dial the fluid pressure back, mix a small/minimum amount of cleaner with water (or use straight solution) and get to places otherwise off limits.

For just a dusty engine bay, I wouldn't go this far. For other vehicles, I've used aluminum foil to cover any electronic/sensitive parts that I didn't want to risk getting wet and just used a garden hose with sprayer attachment and some kind of soap or degreaser depending on how clean/dirty it was.

Afterwards, put on some kind of dressing to keep all the plastic bits healthy and aesthetically pleasing, but one that doesn't attract dust.

Is there such a product?

Paging Crystalworks...

There is. The key is to use a light touch and one that's not oil based. Something like Ammo Mud tire gel.

I've used products from local auto parts stores with varying levels of success.

With any product, a heavy application will attract dust/dirt/pollen/etc.

Lightly wipe on, then buff off. Drive when dry.

Not WD40! lol That attracts all kinds of crap.

I've actually looked into this recently and I see people suggesting silicone spray. It's good for treating rubber surfaces and it doesn't leave a sticky "ArmorAll" film. Obviously if you go heavy on an area you just wipe off the excess. But this spray, and then wipe off, should leave a clean matte finish on the engine bay (from all I've read and seen on YouTube... I've yet to get around to trying it myself)

Had the full exterior/interior detail done. I think on my engine they just used a normal de-greaser then a sealant.

Thought I would share mine. That picture above with the ignition coil cover/s makes me jealous though.

I like before and after pics, so have one close-up version.

I finally ripped everything out of those wells and used some cleaner and pressure washer. Made sure the drains were working and put it back together. Looks much better but not perfect. And yes it is amazing what you find down there. :wow:

https://xoutpost.com/attachments/x5-...day-engine.jpg

Hot Dang this has inspired me! I did this to my wife's 328 a couple years ago, and noticed that my (much newer) X5 needs it now...
This weekend IT'S ON....