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Is there any way to remove the yellowed factory engine coating on my 420??

Ascension

E420 Guru
Member
The stuff is just putrid yellow to black now and is horrid looking. It makes my block and valve covers just look nasty and crusted in dirt on the front of the block where the stuff has turned almost black. Is there any way to safely remove it without damaging other surfaces or etching the aluminum?
 
You can try some various types of thinner....but I find that Usually its exceedingly difficult to remove. I have gotten lucky a couple of times and its only a moderate PITA..

Jono
 
According to Wikipedia: (http://en.wikipedia.org/wiki/Cosmoline)
Cosmoline that is fairly fresh, or that has been hermetically sealed in a plastic bag or shrink wrap, remains a grease-like viscous fluid, and mostly wipes off with a rag, leaving only a thin film behind. Cosmoline that is older and has had air exposure usually solidifies after a few years, as the volatile hydrocarbon fraction evaporates and leaves behind only the waxy hydrocarbon fraction. The solid wax does not readily wipe off. It can be scraped off, although the scraping is laborious and leaves crumbs to be swept or vacuumed away. A useful method of cleaning a tool of crusted cosmoline is to allow a penetrating oil (such as WD-40, CRC 5-56, CLP, or equivalent) to soak into it for several minutes or hours, which typically restores it to a viscous-fluid state, allowing it to be wiped off. An additional method of cosmoline removal on new parts is to use a closed-cabinet parts washer that utilizes the power wash process. Removal of cosmoline with an aqueous parts washer requires high heat, the proper aqueous detergent, and the correct hydraulic impact pressure. Most of these "washing" methods will create a difficult-to-dispose-of toxic sludge.
 
Yeah thank goodness he lives in Alabama and not California ... Probably a felony to remove toxic sludge cosmolene from one's engine there....


Sent from my iPhone using Tapatalk
 
Yeah thank goodness he lives in Alabama and not California ... Probably a felony to remove toxic sludge cosmolene from one's engine there....


Sent from my iPhone using Tapatalk
Probably right about CA Gerry. The idiot liberals that run this state are truly unbelievable.

As for removing the Cosmoline I'm finding that it is a major pain in the a$$. However since I absolutely can't stand it I am doing whatever it takes to get rid of it on my car. That said a good parts cleaner seems to work pretty well but I think if you don't want to see any trace of it your best bet is tumbling, re-plating, etc. Otherwise you just need to pony up for new but that route is not really feasible as obviously costs get out of hand real quick.
 
According to Wikipedia: (http://en.wikipedia.org/wiki/Cosmoline)
Cosmoline that is fairly fresh, or that has been hermetically sealed in a plastic bag or shrink wrap, remains a grease-like viscous fluid, and mostly wipes off with a rag, leaving only a thin film behind. Cosmoline that is older and has had air exposure usually solidifies after a few years, as the volatile hydrocarbon fraction evaporates and leaves behind only the waxy hydrocarbon fraction. The solid wax does not readily wipe off. It can be scraped off, although the scraping is laborious and leaves crumbs to be swept or vacuumed away. A useful method of cleaning a tool of crusted cosmoline is to allow a penetrating oil (such as WD-40, CRC 5-56, CLP, or equivalent) to soak into it for several minutes or hours, which typically restores it to a viscous-fluid state, allowing it to be wiped off. An additional method of cosmoline removal on new parts is to use a closed-cabinet parts washer that utilizes the power wash process. Removal of cosmoline with an aqueous parts washer requires high heat, the proper aqueous detergent, and the correct hydraulic impact pressure. Most of these "washing" methods will create a difficult-to-dispose-of toxic sludge.

Hmm wonder if military grade CLP will work on that stuff? I happen to have a couple cases on hand ( son works in "tactical ordnance" for a defense contractor :agree:).
Thanks for the info guys I had no idea this stuff was dried Cosmoline. Bummer as I hate cleaning up a new military rifle that has been packed with that stuff much less some that has been baked on!!
 
Update on this. Today I spent some time trying to remove the gunk for my valve covers. It flat will not dissolve with anything I have yet tried ( tried CLP,Brake cleaner, mineral spirits, acetone, WD 40, foaming oven cleaner, gun bore solvent you name it and absolutely NOTHING fazed the stuff!!!).
Today I got serious whipped out a single edged razor blade scraper and manually bit by bit scrapped as much as I could off the covers.
Not perfect but a heck of a lot better than it was!!
Before
65.jpg
66.jpg
68.jpg
After
185.jpg
186.jpg
187.jpg
And the tool of choice which was the ONLY thing so far that has fazed this stuff!
188.jpg
 
Last edited:
Looks much better, nice job. I spy a new oil cap too :-)

Thanks and yep wondered if you guys would catch that LOL.
Now if I can just get the mess off the area down around the water pump where it's thick and baked on I would be a happy camper!
 
FYI the later model oil caps fit and are easy to R&R without a death grip.


To clean I've been amazed with soaking things with diluted purple cleaner. Cold engine, soak a rag and lay it on top of the area. Do not let it dry out.. and rinse well.


Michael
 
Never tried a valve cover. You could remove it and put it in a tub with cleaner. That cleaner is cheap in ~<$15 for 5 gallons. FYI I've mainly used it on aluminum parts. I have NO idea on how valve covers will do- I believe they are magnesium.


M
 
Update on this. Today I spent some time trying to remove the gunk for my valve covers. It flat will not dissolve with anything I have yet tried ( tried CLP,Brake cleaner, mineral spirits, acetone, WD 40, foaming oven cleaner, gun bore solvent you name it and absolutely NOTHING fazed the stuff!!!


LOL.... I completely feel your pain, I have been at war with the Cosmoline on my car for weeks now. You are right the stuff is beyond resilient. Fortunately my car is completely torn down to pieces and I have access to a parts washer but that stuff is still fighting us tooth an nail. My old front LCA's and springs were so bad that is seriously looked (and felt) like they were covered in cement! I have not got around to it yet but when it comes to the engine I have already bought a number of different Dremel brushes ranging from Nylon to Brass and I think those in conjunction with some of the solvents you have mentioned will hopefully do the trick in getting all the Cosmoline off the block. That said a Dremel and in your case with the engine in the car a 225-01 Flex Shaft Attachment ( http://www.amazon.com/Dremel-225-01-Flex-Shaft-Attachment/dp/B0000302Y8 ) might be your weapon of choice to take the fight to the rest of the Cosmoline in the tight spots.

:boxing:
 
LOL.... I completely feel your pain, I have been at war with the Cosmoline on my car for weeks now. You are right the stuff is beyond resilient. Fortunately my car is completely torn down to pieces and I have access to a parts washer but that stuff is still fighting us tooth an nail. My old front LCA's and springs were so bad that is seriously looked (and felt) like they were covered in cement! I have not got around to it yet but when it comes to the engine I have already bought a number of different Dremel brushes ranging from Nylon to Brass and I think those in conjunction with some of the solvents you have mentioned will hopefully do the trick in getting all the Cosmoline off the block. That said a Dremel and in your case with the engine in the car a 225-01 Flex Shaft Attachment ( http://www.amazon.com/Dremel-225-01-Flex-Shaft-Attachment/dp/B0000302Y8 ) might be your weapon of choice to take the fight to the rest of the Cosmoline in the tight spots.

:boxing:

If the rest of this stuff is as tough as what was on the valve covers a dremel with even brass brushes wouldn't even begin to remove it. The absolute only way I got results on mine was to get the edge peeling and the blade under the film bit by bit. Labor intensive and frustrating but it worked. Can't get at the areas around the water pump and such like that though. Only thing so far I suspect might dissolve this stuff would be pure lacquer thinner. I'm reluctant to use that stuff because of how corrosive it is in particular with anything plastic.
 

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