[zzinco79]

A quick question.

Can I shampooing the under hood?

Like using brush or sponge to shampoo underhood and spraying the high pressure water.

my underhood is sooo white due to the road salt.

[MarkY]

You would want to cover all areas of the engine where water could interact with electrical contacts.

Spray the entire engine compartment with a cleaner/degreaser

If you use a high-pressure nozzle, be careful that you don't get the nozzle too close to the covered electrical connectors.

Allow the engine to air-dry for a few minutes then use a towel to wipe down any areas where water may have pooled.

Remove the plastic bags then run the engine for a few minutes.

Once the engine is dry and cool, spray hoses, wires and plastic shields with a rubber/vinyl protectant.

You can then spray the entire engine compartment with foaming tire shine spray and it'll look cleaner then new.

[ShinyRedCar]

I use a damp rag and wipe everything down. Spraying water under the hood would make me nervous. If you use a rag, be sure to rinse it out from time to time and get the underside of the hood itself. When you're done, give one last rinse of the rag and do the underside of the trunk lid

[canucklion]

but the underside of the trunk is covered with carpet?

Originally Posted by JGervasi

I use a damp rag and wipe everything down. Spraying water under the hood would make me nervous. If you use a rag, be sure to rinse it out from time to time and get the underside of the hood itself. When you're done, give one last rinse of the rag and do the underside of the trunk lid

[tintivilus]

I know it's from a different era, but I routinely power-washed the engine compartment of my e34 (525) with degreaser to help with the old-engine funkiness. The induced electrical issues I helped keep me on the road -- when it didn't start after power-washing, it was time for an ignition checkup. Once it was due to cracked plug wires, once due to a gnarly distributor.

The stuff under your hood is all designed to get wet when you drive in the rain. If you don't beat the hell out of it with the power sprayer you should be just fine.

[sinnet112]

+1 to what's been said in this thread.

Make sure you cover the things that can short out if they get wet. A regular garden hose will do in this case. Use a product called Simple Green which you can get at Pep Boys or AutoZone. It's a good engine degreaser and everything just comes right off. BMW does a good job covering everything that could get wet though, so for the most part you should be fine. If you don't want to start the car after you hose the Simple Green off, you can also use a leafblower.

[Chesmu]

I wipe down my engine every time I hand wash (every two weeks) THis keeps the engine grease from building up. I just use a damp (not sopping wet) MF towel. The mechanics at my BMW dealership always compliment me on my clean engine compartment.

other threads on this topic:
http://www.e90post.com/forums/showth...ing+engine+bay
http://www.e90post.com/forums/showth...ing+engine+bay

[zzinco79]

So, it would be safe if I'm using regular yard hose?

[sinnet112]

Originally Posted by zzinco79

So, it would be safe if I'm using regular yard hose?

Yes, I've always used that and it's worked fine for me. I've done it on cars ranging from 15 years to 3 years old, without any problems. Just had to cover more stuff on the 15 year old cars

[ShinyRedCar]

Originally Posted by canucklion

but the underside of the trunk is covered with carpet?

Yup...you're right...I meant that I just wipe around the edges and anything uncovered. It's not much I know but hey...it's in the details

BTW and fwiw, I read somewhere once that a study was done that suggested mechanics tend to be more diligent when working on a clean car. It was some time ago and I don't remember all the details but this much I do remember. As a result of that, I always clean my cars (E46 and E90) before bringing them in. It's kind of nice getting positive comments from the service guys about the condition of the cars.

Have a great day everyone