Prepping engine bay...

[mazur]

Since I'll be doing an S50 swap, I figured I'm going to paint the engine bay while it's empty because most of it is some nasty yellow color (my car is Alpine)

How should I go about prepping it. I plan on power washing the whole bay down, but not sure if I should sand it all down a little (sounds like a PITA).

[backtrail69]

You are going to need to clean it really really well with a degreaser first, then sand it all down with like 220, primer it, then sand all that down with 320 and then 400 wet...thats teh only way id do it.. (lots of work)

[DarkWing6]

I bet cleaning and polishing it will take care of most of that yellowing. If there is cosmoline that can be taken care of without painting as well.

[browntown]

I haven't deciding on painting my bay or not, the powerwash idea isn't bad. I'd probably soak it down with simple green first though. I was thinking just por-15'ing the engine bay with a glossy light grey to make leaks easy to find, and will never have to pull the motor to get at a rust spot. Plus, although I haven't used the product before, I would think application would be light years easier for the DIY'er. dunno.

[mazur]

You are going to need to clean it really really well with a degreaser first, then sand it all down with like 220, primer it, then sand all that down with 320 and then 400 wet...thats teh only way id do it.. (lots of work)

I might just do this. I think the extra work to do it right will be worth it in the end.

So...how many bottles of simple green should I buy...5? ;)

[euroshark]

Having grey or black in the engine bay is a great idea imo. It might not match the car, but it's much more practical I think, especially like browntown said for finding leaks etc. I think some of the older BMW models came with flat black engine bays (my '81 6 series is all black in there, and there is nothing under the paint but metal, and the rest of the car clearly used to be Polaris. My dad's '79 is the same way.) Old School FTW.

If you want some bad ass degreaser, get the spray can brake parts cleaner. Holy shit, grease just flies off instantly...

[Simon S]

fwiw: i found that moistening a rag or paper towel with acetone worked great for quickly removing cosmoline - just need to be super cautious with quick swipes.

Acetone will knock any and all shit out of the way - it also evaporates rapidly - so with caution, it can do the job while causing minimal damage to paint below.

[mazur]

I was on theeurodepot.com and saw that sell BMW paint in an aerosol!

This could be a cheap way to do the job quickly. Just clean up the engine bay good and give it a spray of paint. Would anyone suggest not using this stuff?

[golde30]

if you use one of those high pressure steam cleaning guns(professional stuff, not the one from the infomercials), i have found that it takes cosmoline off. take forever, but it worked on my old 325i, took all the cosmo offa the valve cover.

[Ben Carufel]

I bought a bunch of Griot's Engine Cleaner a few weeks ago (cost a frickin' fortune). The stuff is amazing. Girlfriend and I did the engine bay of her 77k mile '04 WRX and it sparkles like new.

I'd highly recommend it.

As for cosmoline...can't remember how I used to take that off.

[StereoInstaller1]

Guys, here is easy, classy, clean and sexy as hell:

[Beej '86 325es]

If I had to do it again, I'd probably start with a steam cleaner and save myself a couple bottles of Simple Green. Then wax. It can look good...not perfect...but good without paint.