Captain_Slow

I've started taking the top of my engine apart for a "components only" intake and cam cover refresh. I'm thinking about what to use to degrease and clean the factory painted intake and cam covers. The paint is still in good shape (as far as I can tell). I once mentioned to Greg Nichols that I occasionally spray the weeping cam cover bolt seals with a little brake cleaner and wipe off. His response was along the lines of "You did what?!?" Then he told me that the only reason he had to do his intake refresh many years ago was because he tried an engine cleaner on his and it caused the paint to fall off.

I'll be cleaning mine when it's off the car. Please post what you know works well without damaging the paint. Even more importantly - post what you know NOT to use based on unfortunate experience. I hope this thread will help anyone who is not planning to strip and repaint/powder coat their cam covers and intake.

XS29L9B

I bought some Purple Power cleaner the other day to clean an engine bay, then read the fine print which said, not for use on painted surfaces... Sigh.

I will stick with simple green and brake cleaner spray.

worf928

Captain_Slow

Calling Dr. Bob in 3....2....1 to give the warnings about Simple Green. I think he said it ruins electrical connections.

XS29L9B

...my ears are open - and good thing it's too cold to wash anything out in the garage anyways. Subscribing to the thread. Thanks,

The Forgotten On

Simple green also eats away at aluminum and the magnesium alloy our intakes are made from.

FredR

I use soapy water but very sparingly on a wetted kitchen sponge [those yellow things with a green scouring pad on one side]. If there is oil on the surface I might use a degreaser- just test it in a more obscure location.

worf928

Captain_Slow

What about using a small home steam cleaner? I think Bob V says he uses one exclusively to avoid solvents (and probably to avoid using lots of water under the hood).

dr bob

Follow Dave C's advice on this. Similar to the experience related in the first post, I grabbed a spray bottle of my favorite detergent at the time to clean the top of the engine. As I went to squeeze the trigger the second time, I could already see the effect on the paint. Couldn't get the stuff off fast enough. Original pristine finish now featured tear trails -- from the detergent, plus my own. I lived with that for years, until a big patch of the original paint blew off the intake while I was cleaning in there with a very dilute car wash soap mixture followed by distilled water rinse, and compressed air to dry. The ejected patch of paint kind of forced the subsequent intake refresh.

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Simple Green, at least in the non-aero consumer and pro-sumer versions, has long-term corrosion issues with aluminum. I use it under the car, almost always diluted some, but always with some serious rinsing, a follow-up with car-wash soap and another thorough rinse.

Most green-can brake cleaners are a blend of acetone or other low-boiling solvent, and a little higher-boiling solvent of some kind. The "good stuff" in red cans has some chlorinated solvents added to help with cleaning, but that adds some health risks. All of the brake cleaners are fat soluble, and pass "handily" through skin, nasal membranes, lung tissue, eyes, etc. Then cause nerve damage as they pass into and through the blood stream, especially the chlorinated versions. There's a reason why three-quarters of the info on the label is health warnings. As far as using it for general cleaning, consider that it leaches the plasticizers out of common PVC-insulated wiring, including cable connectors. Many hoses under the hood suffer the same fate with extended exposure to brake cleaner. Notice cracks and stress fractures around the base of the oil filler neck after a short life of brake cleaner as a detailing spray? Which rule number is the one about "no such thing as a coincidence"?

Virtually all the "Purple" degreasers, regardless of brand name, are pretty caustic. Caustic is a pretty good fat dissolver, but it also reacts with aluminum to make aluminum hydroxide. That's a dark grey skin cancer that forms on aluminum, trashing the bright and/or smooth surface finish to make it look rough cast. Unlike the protective oxide layer that aluminum slowly makes natively when exposed to air, the hydroxide layer offers no protective qualities; the aluminum is still slowly destroyed under that pretty dark grey surface. Bottom line: there are undoubtedly great uses for purple degreasers, Just don't let it stay in contact with anything aluminum or painted, your skin or your clothes. That pretty much rules it out for use on the 928.

I look for high-boiling solvent-based cleaners for really serious cleaning projects where I can avoid wires, painted surfaces and the plastic parts. And only after the majority of the crud has been wiped off or maybe pressure-washed off. For the painted, plastic and aluminum surfaces, the P21S Total Auto Wash has emulsifiers that wrap around the oil and grease molecules and allow them to be carried off in rinse water. Much less of the substrate goes along with it.

Small steam cleaners are great for softening grease and oil, making them much easier to wipe off. Commercials steam cleaners in experienced hands are among the best weapons for cleaning under the car, so long as you avoid the alternator and starter, and the front of the AC compressor. In the rear, the electrical stuff on the transmission needs protection too. Otherwise, have at it with steam, just don't cook any of the paint or other protective materials off with it.

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I happen to like Dawn liquid dishwashing detergent for lots of things. It's pH neutral enough that you can use your bare hands to use it, but extended exposure probably deserves gloves anyway. It rinses pretty well, at least well enough to be able to get tableware at least looking clean. It works pretty well in ultrasonic cleaners too. It's pretty good for chassis detailing with a toothbrush, rinsed with distilled water and wiped dry.