Any advice on this?

My valve covers have a mottled, white "substance" on them. Not sure what it is...reminds me of what aluminum does when exposed to salty moist air. This car was not near any ocean, however. It's previous life was in Washington, DC.

I opened the hood for something yesterday and noticed this "stuff" again. I thought about having the engine detailed, but did not want to screw anything up.

Thanks for any advice you may have!

 

Most likely it's soap residue from washing the car. Try just plain water at first, then maybe a mild aluminum cleaner.

 

Can you just hose down the engine bay gently? I have that stuff too

 

I start with a cold engine, wrap electrical connectors & fuse boxes with foil or plastic film. Then I spray degreaser all over, scrub a bit here & there, and rinse it all off with a gentle indirect spray. Wipe things down & you're done. Look great!

 

As above, but I apply vinyl and rubber dressing while still wet then dry with a blaster and let it stand overnight before driving. It should look good for a few months, the water dosen't tend to stay on and cause staining.

 

Hmmm...hard to trust myself to cover all the electrical stuff. I'd hate to fry something.

 

The valve covers have a plastic cover over them, you can pop them off and clean them up with a good degreaser like Simple Green and a soft bristle brush. You can clean them on the engine as well, just be careful not to get too much water all over the engine. Since the vents on the hood are open to the elements, the residue is most likely polishing compound from a detail at some point and it will scrub off with soap and water and a soft brush.

 

Thanks for all the good info. I fried some electrical stuff on my 96 XJS some years ago doing something like this and have been gun shy ever since.