Eversince I started wrenching for hobby in lets say 1981. I had an old mechanic tell me to liberally spray the entire engine down with WD-40 to the point it is dripping, on any new project you buy.

Been doing ever since, works great for cleaning hoses metal etc. helps loosen dirt and grease so when you do wash you motor down it take less time and degreaser. respray and displace the water from important electical contact.

It burns off quickly, and leaves a nice film that makes cleaning easy later.


I will say dont spray a fresh hot motor or one that is running. let it cool for a bit.


Thanks guys hope this helps.....

 

If you are going to do that, you might as well buy the gallon jug and the spray bottle. I did pick up a gallon of it a couple of years ago at a little country store that sold all kinds of surplus stuff cheap and a whole tub full of McGuires Car Polish and other similar product but the WD40 is long gone. For our older corroded Discoveries, we had to step up to PB Blaster. Great Penetrant and according to the can also safe for electrical.

 

Kerosene does the same thing if you can stand the smell. A lot of folks use that stuff to make raggedy old engines nice and pretty again.

 

You can buy WD-40 in gallons in lots of places, like even Home Depot. And cheap garden pump sprayers work well for light oil. Ever seen a guy oiling the track on an escalator?

 

I did this once on an old BMW.... It took the paint off of the valve cover.

 

WD-40 should not harm the paint. I also don't remember many BMW's with factory painted valve covers so that could indicate a poor prep job before someone sprayed it.

 

Wd-40 is about 50% Aliphatic Hydrocarbon
which is deoderized kerosene,
and has some other solvents tossed in there.

Always test solvents in a hard to see spot.

 

If the hood is shut it hard to see

 

Anything will take off that paint, it doesn't last lol

 

Used Water Displacement 40 for years.... I'm now using Blaster, which works really good. From personal experience with built up LR grime, it cleans really nicely...really loosens up the dirt.