Pressure Washing an Engine-83 240D
 

My engine has never been cleaned and is REALLY dirty, has anyone had any problems pressure washing an engine? What do I need to be careful with? Thanks.

Josh

Take it to a car wash and use their green engine wash, make sure that the air intake is closed and do not spray directly on the starter/altrnator.
The car wash green stuff is not very strong in removing old stubborn buildups but if you make a habit of repeating this once every couple of months you will clean up that baby real good.

Vahe
240D 77

Could be a problem with driving it to a car wash and using their equipment. In that instance, the engine would be up to normal operating temperature and you could cause a problem, particularly with the IP if you hit it with cold or even warm water. The IP has some really close internal tolerances and they don't like sudden temp changes.

I would pressure wash it cold at the house. I would also use Gunk or some other engine cleaner to help dissolve the layers of grease. A good aggitation with a stiff brush would help too.

After you finish washing it, start it up and bring it up to temp to assist drying. While its doing that, you can soak up and wipe up some of the residual water. (Watch out for moving parts/belts.)

You'll enjoy working on and driving with a clean engine.

Wes

I do mine all the time
 

I pressure wash my engines all the time. Like the other post said, just try to stay away or at least cover the sensitive electrical stuff. Before pressure washing, I spray my engine area with a degreaser first using a spray bottle. I like the degreaser I find at Walmart (its purple) but other places have them too. Very good at removing stubborn grease. The expensive one is called Super Clean and the Walmart brand is Purple Power.

Let it sit for a few minutes per instructions then presuure wash.

NEVER, EVER wash a hot engine! Maybe warm to help loosen stuff but if it has been running/driven more than a few minutes you can do far more harm than good spraying cold water on it...that's one of the primary reasons why the pros use steam and not water.

I prefer to clean it at home with a can of "Gunk" type degreaser and a hose. Spray on the cleaner, wait a few minutes and rinse; repeat as required. As others have said, avoid spraying water directly on the electronics.

Let the engine cool for at least 5 minutes.
Be sure to wrap your brake reservoir with a plastic bag. Brake fluid will absorb any water that contacts it.

Thanks for all the input, I think I'm gonna have to take a paint scraper to it first theres so much build up!

Not When Hot
 

Made the assumption that YES don't wash the engine when its hot. I do mine on weekends when I move it out of the garage to the driveway and do my thing.

Gunk will do wonders in getting almost all of the grease etc. off but I would not leave it very long on painted surfaces.

I use it all the time and if left on too long (more than a few minutes) it seems to fade the paint badly. A few minutes should get off all the petroleum based deposits anyway. Especially if agitated with a brush.

Next, I use the orange citrus based cleaners which will do a great job on oily deposits and dirt. It does not seem to hurt the paint either.

Simple Green will also do good but the orange seems to dissolve the oily substances quicker.

A car wash is OK but by doing it at home, you can work on either a cold engine or a barely warm one. I have not seen any difference between cleaning a cold engine and a warm one with the chemicals that I use.

I've washed my engine at the carwash with the engine hot, but not straight off the highway hot, with no problem. when the engines warmed up slightly it makes the removal of stubborn oil and grease MUCH easier. any home pressurewasher will only be able to use cold water which will do nothing .

I asked the attendant, who's a friend of mine what the water temp was coming out of the nozzle and he said they use a natural gas, on-demand hot water system which gives 90*C water at all times....