So, we bought a thing. Like most bought on an impulse cars in my life I'm taking it apart and cleaning everything before actually driving it. There will be a build thread coming, but right now I'm stuck.
The entire engine bay is covered in a thickish layer of this gunk:
5 internet points to anyone who can tell me what this junk is or how to clean this off. It's on every surface - plastic, wiring, strut towers, intake, bottom of hood, etc. It seems to chip off rather than dissolve in anything. So far I've tried the following to no avail: mineral spirits, brake clean, purple power, simple green, dish soap, a power washer, and yelling at it.
My current working theory is oil spewed everywhere, then was well baked for about 25 years. 1 additional bonus internet point for the first to identify the car...shouldn't be a tough one.
Looks like an E30 - or some BMW with an M20 in it. In which case - that's cosmoline. I never bothered trying to clean it off mine, but the internet says diesel works great - or Wurth engine cleaner and degreaser.
Duke
MegaDork
11/20/17 5:12 p.m.
Uhhhh, why wasn't cleaning the cosmoline off the engine bay part of the dealer prep when that thing was new?
Duke said:
Uhhhh, why wasn't cleaning the cosmoline off the engine bay part of the dealer prep when that thing was new?
because dealers are full of people and people make mistakes.
Hmm... Did you try chlorinated or non-chlorinated brake cleaner? The similar looking (when dried) CRC SP400 definitely comes off with the chlorinated stuff and some scrubbing. I'd expect Cosmoline to do the same (it's similar stuff). Acetone would likely work too.
Yeah, basically every e30 with an M42 was sold with the cosmoline still all over the valve cover, and lots of M20s too :)
I'm pretty sure I just wire-wheeled it off of mine.
I cannot argue about what engine we're looking at, nor that that's cosmoline, but offer a dissenting opinion just to be contrary:
Lots of used car dealerships cleaned and clear-coated everything under the hood. It really makes stuff look sharp-like armor all or some such. And what the heck, its a 944 Porsche engine.
I expect to be wrong on at least one count.
German waffle maker with spilled maple syrup??
You guys are the best! This was so much more instructive than the Google. Good job to those that guessed right...here's the car in question:
It's an '87 E30 with the wrong kind of top. However, it is a lower mileage manual car and in better shape than most of the garbage I tow home (I think). This car is the second attempt to get the wife interested in cars.
rslifkin said:
Hmm... Did you try chlorinated or non-chlorinated brake cleaner? The similar looking (when dried) CRC SP400 definitely comes off with the chlorinated stuff and some scrubbing. I'd expect Cosmoline to do the same (it's similar stuff). Acetone would likely work too.
I tried chlorinated brake clean. No dice. Acetone is a good suggestion...I'll give it a go tomorrow.
irish44j said:
Yeah, basically every e30 with an M42 was sold with the cosmoline still all over the valve cover, and lots of M20s too :)
I'm pretty sure I just wire-wheeled it off of mine.
Interesting. This is my first bmw from before the 21st century so I have zero familiarity with these engines. Weirdly, it seems to be on a lot of other underhood components as well.
Will
UltraDork
11/20/17 8:01 p.m.
Lots of old gun stuff got coated in cosmoline as a preservative. If you can't find an answer here, go to a gun board.
essentially for the gun stuff you soak it in simple green or brake cleaner and leave it in a bag in the sun in the middle of summer for most of the day. But that is to get cosmoline out of wood.
Simple green works really well to get it off but will wreck aluminum if you are not careful.
When you said "so we bought a thing" I thought you bought a VW Thing and I was very confused by the engine pic. The BMW looks great!
Kerosene then a wash.
AC VW's were shipped, covered with cosmoline. Engines were not treated.
That's how we did it at the dealership.
Some guys actually keep the cosmoline under the hood as a mark of originality— I talked to a guy with a mint 850csi with under 50k miles and he still had all of the cosmoline because apparently collectors like that stuff.
MrChaos said:
Simple green works really well to get it off but will wreck aluminum if you are not careful.
The aerospace Simple Green (which I *think* is the same as the Extreme stuff) is aluminum-safe. I'd double-check me before doing anything critical, but that's what I found before getting five gallons for the parts washer.
Googling 'e30 cosmoline removal' turns up lots of hits from the various BMW web boards. As always, take most of the replies with a grain of salt but there should be some useful information buried in there someplace. I saw a mention of a Zymol product several times that's supposed to work.
I've been driving e28s and e30s for close to twenty years, but personally haven't gotten around to doing much about it myself. 
I know on guns that gasoline is a widely used substance to remove cosmoline. I'm not sure that's the best bet under the hood though.
