I'm told that, for regular American and Japanese cars, we can use a hose to rinse the whole thing under the hood, just as long as your engine is running. Most parts under the hood are water-proof.

Can we do the same to our E60? The engine cover and surroundings got very dusty...I wonder how I should wash everything.

Thanks.

 

Do not do this.. You will be sorry.

 

LOL, I can't argue with that!

I use a bottle of Simple Green/water and do the spray on, wipe off motion. Anymore than that, you can potentially be looking at a shiny, non-running engine with Christmas lights all over your dashboard. lol

 

I just take a damp microfiber cloth and just wipe it down. As long as your underbody panels and fenders are intact it shouldn't be that dirty.

 

Mostly lower part of engines get dirty by leaking oil and other fluids. Once a while cover the electrical components in my case I only cover the alternator with aluminum foil. Spray a warm either not from top but from start engine block then spray with mild engine degreaser simple green works, wait for few minutes use e brush to get some caked oil and dirt out then spray with warm water again. Use a leaf blower or air compressor to dry the engine wipe it clean with cloth wait for hour or so then start it. For top of engine remove the engine covers and blow the dust with blower use a wet cloth for the first time to clean it then dry with clean cloth. Once it is clean I like to use the aerosol 303 spray as it is not greasy and last long and safe for all materials especially for plastic and rubber like covers and hoses. Once you do this maybe once a year then if you wish to keep the engine clean and do not want to spend time on this again I open the hood by every time I wash my car, blower the water and wipe it with the microfiber cloth I am using to dry my wheels. That way engine will look always clean but if you want you engine's lower part to be clean and free from oil and grease fix the leaks if it is leaking.

 

Well, I've done it at a self-wash bay 3 or 4 times in the last couple of years ... with no bad result. I hosed it down with the soapy spray, then rinsed it off during the rinse of the rest of the car. (2009 535i)

I've been doing this over the years with a number of different cars (BMW's included) ... again with no problems. Maybe I've just been lucky, or maybe it has to do with the fact that the engine was hot when washed (turbo's get especially hot), and that evaporated the water before it could cause a problem.

But I'm not necessarily recommending it, just sayin' ...

(By the way, the engine was not running when I washed it, and started up fine each time.)

 

Thanks for sharing all your experience!!

There was a leaking from the engine oil filter gasket, I replaced the gasket myself, but did not clean the lower parts for all the greasy oil. Theoretically, as long as the alternator is covered and the engine is hot, water should cause no big damage, right?

Did anyone can recommend any cleaning solutions? Green Water seems very professional, but there is supplier in California. Meguiar is having a sale, anyone used them?

 

I too have washed my engine. It's mainly dust etc and I normally just lightly spray water on it and not concentrate it in any one area. If course it's cold and after I'm finished I start the car and let it idle for a little. I've done this a handful of times over the past few years. Maybe I've also been luckly.

 

I don't think it's a good idea to pour cold water on a hot engine. I think you can crack an engine block that way.

 

Simple Green has been known to not be friendly with aluminum. Ask the folks over on the Mercedes sites. Gives it a dull, corroded look. If you use it do not let it set long.