Engine bay cleaning and degrease

[240Z-Fan]

Hello all,

I have a 1973 240z. The front main seal was leaking and made a bit of a mess under hood. I pulled the engine a while back to reseal the engine a long time ago, and am now just getting back to it.

I removed the heavier grease buildup back then, but now I want to cleanup the rest of the grease and grime. (See picture.)  However, I do not want to damage the paint, the wire harnesses, or any other components.  

Does anyone have any recommendations for a cleaner that would be safe? (Eg Simple Green Crystal, or Purple Industrial Cleaner, D108)

Any preferred techniques for cleaning it?

Thanks!

Luis

 

[7tooZ]

I have used “Oil Eater” for years. You can order it through Costco in gallon Jugs or 5 gallon pail. Spray it on let it sit and then spray it off with water. Use a brush for hard spots. I also use Gojo on a rag on my engine bay.

 

[grannyknot]

The purple stuff works great because it is Lye based but will definitely dull the paint, Simple Green is milder so will take longer but works. I would use a plastic scraper to get the worst off then some diluted Simple Green and an old tooth brush, after everything is clean and dry you can hand buff with compound/polish to bring the shiny back.

The more stuff you can remove or pull away from the metal the better it will look.

Edited June 25, 2020 by grannyknot

[siteunseen]

That looks like soot more than grease to me. Like the black powdery grime off a belt, maybe the a/c and alternator belts? I used Murphy's Oil Soap on mine for the lighter stuff like your picture. It worked good for me FYI.

" It is also commonly used to clean black-powder weapons after use, since the lack of petroleum-based oil and the presence of vegetable oil lessens the amount of sludge that is created when cleaning black powder residues from weapons. It has also been found to efficiently remove the residue that builds up on automobile wheels and hubcaps from the disc brakes."  Wikipedia info

https://en.wikipedia.org/wiki/Murphy_Oil_Soap

Edited June 25, 2020 by siteunseen

[cgsheen1]

I learned in chemistry class back in the '60's that "like dissolves like". (When I had greasy hands my Mother would slap a daub of butter on them before I washed - a little sand in there helps too) That's single stage alkyd paint and after this many years contaminant is surely ingrained in it's surface. Nothing is going to remove all of it (except sanding off the top layer and buffing what's left - not practical in an engine bay). But cleaning/degreasing and then using a good cleaner wax should suffice. Sorry Granny, I would never use a scraper of any type unless I was planning on repainting a part or surface. In the shop we use some wax and grease removers developed specifically for paint but they're very expensive and generally not sold retail. 

You've got the engine out of the way, why not pull some of that other stuff out of the way too. The wiring harness is fairly easy to pull back through the radiator core support and move away from the frame rail. A little Meguiar's Hyper Dressing will make the exterior of that harness look like new. Hoses and plastic too.

[grannyknot]

3 hours ago, cgsheen1 said:

Sorry Granny, I would never use a scraper of any type unless I was planning on repainting a part or surface.

I should have been more specific, I use these cheap throw away body filler spreaders, very flexible.

 

[cgsheen1]

Use them often in the shop - for spreading icing (fill) and the like.

[240Z-Fan]

 

Good thoughts here, all

I was hoping to avoid a lot of disassembly. Not so much because it is work, but because I didn't want to risk breaking fasteners or cracking paint.  However, it is looking more and more like it may be the better way to go. 

I did order some brushes that were recommended by some youtube auto detailers so I can get in the tight spots.

Great ideas, keep them coming, please!