how to remove this stuff..

[polisher]

so ok this is the air intake and how would i go about cleaning it..is there some household stuff i can use like simple green or baking soda or vinegar ? i have included a cleaner engine bay when car was new.
thanks

 

[classofshine]

Looks like it has become discolored from heat. If that is the case then its not going to be removed. What about painting it?

 

[mrclean81]

That's an easy fix. Acid based wheel cleaner.

Edit - I should elaborate a little. Get an acid based wheel cleaner, dilute it way down at first. If you don't it will turn the aluminum white. Start with a high dilution ratio and mix it stronger until you start seeing the results you want. Wear some latex gloves because its acid after all. Lightly scrub it with a brush or two, and rinse thoroughly. Do NOT let acid set to dwell ever. The longer it sits the more it works, which isn't a good thing. Spray, scrub, rinse. Its that easy.

 

[Nth Degree]

If it can be removed without too much trouble it will make things much easier. Then you can test products on the back side where it won't be visible. If it is, in fact, dirt and grime, some carburetor cleaner might do the trick. If it works for the inside, it should work for the outside. Throw some towels over any plastic or electronics around it first.

 

[polisher]

hmm will try those products..but as for Acid based wheel cleaner...u mean like a regular rim cleaners? Meguiar', auto glym, black magic , turtle wax rims cleaners?

 

[mrclean81]

Eagle One A to Z is a decent one. Most wheel cleaners are non acid, but that might work as well. My suggestion was based on the assumption that you'd tried several products with no luck. Even if you buy one over the counter, you still need to dilute it even more. Try the other suggestions first because this is by no means the least aggressive method, but its a good last resort.