2G How does everyone here clean their engine bays?

[TheDude236]

I'd like to clean my engine bay the right way before I put the engine back in the car. My engine bay has a lot of oil residue everywhere due to an old leak, and it also has a spot of something that looks like early rust. I'd love to pressure wash it but my car is currently on jacks without a way to be rolled out into the driveway, so what are some of the ways you guys clean your engine bays out (Aside from pressure washing)? What materials do you use? Any special method to take note of? Or is it just a job for some purple power and 30 rolls of paper towels?

 

[AWD-Tony]

Degreeser & soft brush a few times. Lay down cardboard helps with clean up.

 

[XC92]

I'm no expert and have never done it with the engine out but my method is to liberally spray a combination of engine-safe cleaners like Super Clean and Gunk on all the dirty, grimy and greasy parts, scrub everything with tough nylon brushes and scotchbrite pads, then spray it all down with water. Then repeat as you won't get it all in one pass.

I know that you're supposed to cover all the electrical parts and connectors with baggies, and I've done that sometimes. But even when I haven't nothing happened, although I did wait a few days to let everything dry out before turning the engine on.

If there's any loose stuff like leaves, sand, spider cocoons, etc., I remove those first before any of the liquids get applied, with soft implements like chopsticks and then maybe a car vac. It's not really that complicated. Use common sense.

 

[pauleyman]

I don't care for the petroleum based cleaners except for parts I can thoroughly wipe off or parts already off the car. I prefer a water based cleaner. Simple green etc. Lots of elbow grease and time. If you want to minimize mess a pump sprayer and plain water to rinse would be much less mess than an open garden hose. If you want to spend a few extra bucks rinse with distilled water and no spots left behind.

 

[XC92]

The water-based stuff will eventually get most grease and dirt off but there are places where Gunk is really needed, especially if you've had oil leaks in the past. Or am I misunderstanding what you mean by petroleum-based cleaner? What are Gunk and Super Clean? Are you referring to brake cleaner and the like? Yeah, I don't like those either.

 

[AWD-Tony]

I wouldn’t use scotchbrite since that’s basically wet sanding. If you really need to get at it, use a soft dish wash sponge.

Always take the least aggressive approach with anything. Then step up gradually if need be.

 

[1990TSIAWDTALON]

But.....what does the wife say when you do that?????

 

[XC92]

I wouldn’t use scotchbrite since that’s basically wet sanding. If you really need to get at it, use a soft dish wash sponge.

On paint, sure, but on unpainted metal parts like fuel and brake lines, cylinder head and block, thermostat housing, etc., I go to town with abrasive products. Especially on parts that get pretty cruddy after years of use like the engine rear and front. Unpainted, hard metal, so long as I don't gouge mating or sliding surfaces, I don't worry about scratches.

 

[pauleyman]

A good selection of quality soft brushes is an investment. If have dedicated brushes for under hood vs interior etc.

On paint, sure, but on unpainted metal parts like fuel and brake lines, cylinder head and block, thermostat housing, etc., I go to town with abrasive products. Especially on parts that get pretty cruddy after years of use like the engine rear and front. Unpainted, hard metal, so long as I don't gouge mating or sliding surfaces, I don't worry about scratches.

I'm going to disagree also. Only thing I might use a scotchbrite on is the most rough of cast items and even then liberal cleaners and brushes do a better job for me. I have some stiff bristle brushes that will cut through even tough caked grease. If it's bad enough I will use some plastic or wooden scrapers first to get the thick stuff off.

 

[AWD-Tony]

But.....what does the wife say when you do that?????

The worn ones ready to be thrown out. Then she can’t say a WORD!!!

 

[XC92]

I actually don't use scotchbrite all that often either but for different reasons, that it's hard to use effectively in many areas. But not because of scratches. Where I use it I'm not worried about that. Hell, when I cleaned my wheel wheels I went overboard and used metal wire brush attachments on my drill. Took off not only decades of caked-on grey crud but also some paint. Nothing that some primer and paint didn't fix, though.

 

[pauleyman]

If anybody want to see some neat cleaning. Lookup dry ice blasting. It's not great for super greasy stuff but for stuff that's already "clean" but has that caked on brown, grey crud, etc from just age. Dry ice take it back to literally showroom clean assuming what's underneath is good. And I mean new and untouched looking. I was impressed. Underside chassis looked brand new day 1 in some cases.

 

[TheDude236]

If anybody want to see some neat cleaning. Lookup dry ice blasting. It's not great for super greasy stuff but for stuff that's already "clean" but has that caked on brown, grey crud, etc from just age. Dry ice take it back to literally showroom clean assuming what's underneath is good. And I mean new and untouched looking. I was impressed. Underside chassis looked brand new day 1 in some cases.

I actually have heard about that! Its crazy lookin! Its probably a lifetime away for my car but for a complete restoration it would be pretty much perfect.

 

[pauleyman]

In the end elbow grease will get most of the underhood clean. The only parts I would not clean well were raw aluminum. When I had my trans out even clean it still looked dingy. It was not greasy even a little but. I had it glass beaded during a rebuild. Dingy aluminum can be cleaned by hand but it's more work than I want. Aluminum intake is rough cast so used an acid based wheel cleaner when off the engine. Acid has no place around painted surfaces

 

[AWD-Tony]

Dry ice blasting and glass bead blasting for aluminum are the sh!t!!! I need them in my life.

 

[Kryndon]

Recently did it on my Talon and on my brother's VR-4. Removed MAF/airboxes and batteries of course, then put a plastic bag over the alternator and any connectors which were loose (bags didn't help, water still got in 'em but whatever). Sprayed with a garden hose, then sprayed liberally with a real strong engine/carbon degreaser (brand Motox) and worked all the nooks and crannies with a soft bristle brush that I could reach, which was about 60% of the engine bay. Sprayed a bit more degreaser then hosed it all down with water. Left it for a full 24 hours to dry, with no ill effects. Ended up pretty nice and clean and if you go in with some sort of detailing spray it will make it all pop even more. But I constantly get compliments on how clean my engine bay is. The only thing that's been deleted is the AC; everything else is still on there including good ole Tom Cruise.

P.S, for the underside/oilpan and lower portion of the trans, I like to waste 1 or 2 full cans of brake cleaner. It really gets in all those stupid small places and properly displaces the grime. Typically once you take care of all your leaks and clean the bay this way, it will stay nice and clean for quite a long while.

 

[XC92]

In the end elbow grease will get most of the underhood clean. The only parts I would not clean well were raw aluminum. When I had my trans out even clean it still looked dingy. It was not greasy even a little but. I had it glass beaded during a rebuild. Dingy aluminum can be cleaned by hand but it's more work than I want. Aluminum intake is rough cast so used an acid based wheel cleaner when off the engine. Acid has no place around painted surfaces

I manually cleaned my trans when I had it apart. Literally every part including case and internals. The case was tough to thoroughly clean, but having it in 4 sections with every part removed made it a bit easier. I used various types and sizes of wire brush wheels on both an impact wrench and rotary tool, plus nylon and metal brushes and degreaser.

Got it about as clean is was possible without special equipment. Then I primed and painted it with Duplicolor Engine Enamel (outer surfaces and bell housing only, not inside), and I was impressed with the results. That's pretty tough paint, dries fast, and looks pretty nice IMO. I had to touch it up a bit after parts of it got scuffed up during reinstallation, but not too much.

Aluminum's kind of weird. I assume that the dingy parts are aluminum oxide (i.e. rust) and the white crystals are some kind of salt like aluminum chloride, although I'm not sure what it reacts with to turn into that.