Cleaning engine bay: wise?
 

Hi All,
Engine bay is getting dirty. Is it wise to clean it? I don't care about looks, but maybe cleaning is good for performance. Is it bad to leave it 'dirty'?

Cheers!

It depends on how you are planning on cleaning it.
A clean and shiny engine bay is always a good thing. It's nice to work on a clean engine and it looks good.
What is NOT nice, is having an engine with all sorts of electrical malfunctions caused by water getting everywhere if you use pressurized water and/or steam to clean it.

Use a good engine cleaner spray. (don't drown the engine in it) Let it sit for while and rinse it off with a little hot water and a brush. Whipe off with a cloth afterwards.
Always check spark plug wells for water when you're done!

Works for me..

Freestyler

I've been cleaning the engines in all my cars at the coin operated car wash for over 30 years with the worst ill effects being water in the distributor cap condensing and requiring drying out.

Good luck,

steam cleaning makes the engine bay "like new". as you may have surmised, the only concern would be the electricals. anybody reading this with a '93 - '95 w124 take note. if you have not had your wiring harness replaced don't even think about it! i've had mine replaced and i still won't ever have mine steam or any kind of water cleaned even though i would do it on other cars without hesitation.

The CD manual addresses this procedure and shows what areas need to be protected during engine cleaning.

I too have experienced problems with aggressive engine bay cleaning, most of them related to water getting into the distributor cap.

I did my 123 engine bay at a do-it-yourself pressur washing place on the weekend and ended up killing my dash lights. Probably just a fuse, but a pain in the ass. Oh well, at least my engine bay looks good, even if I can't see how fast (or slow, being that it's a diesel and all:p) I'm going at night.

Mostly I went there to clean off all the degreaser I used at home - after a good rinsing it still emitted a strong chemical odour, so I used the pressure washer which helped immensely.

If you want to go the extra mile........
 

Spend a weekend hand cleaning your engine using Simplegreen. It will remove oil/grease and built up dirt. Spend extra time removing the air cleaner and cleaning in the crevices. Make sure to cover the air inlet to your engine. Use a damp rag to remove any Simple green residue.

Once you done this you can easily maintain it with quick detailer (or water mist) and a rag. You can also use an air compressor to blow off loose dust.

I've had problems with hosing down engines on other cars and my thought is, what would cost more, replacing major electricals or spending extra time hand cleaning. The hourly cost of hand cleaning will always cost less!

simple green now comes in wipes which is what i use in the engine bay. another tip i got from my mechanic was to use the mist setting on a garden hose nozzle (found in the ones that have multiple spray patterns), if you really have to use a hose.

To add to the Simple Green responses, Simple Green does make a spray engine degreaser, similar to the Gunk, but a few cents more. Doesn't have the same smell as the Gunk Engine Degreaser, which is a plus.

just an idea.....
 

to avoid elec problems while rinsing off cleaner would it not make sense to have the engine running to avoid standing water and then ,maybe,take it for a quick spin?

On a 126 car, I lay an old sheet along the back in the section between the battery and fuse box. No sense in getting this wet. I believe you could do something similar with some of the 124 cars as well.

I live about 150 yds. from a car wash, so I don't have to worry much about washing too hot of an engine. You can crack the exh. manifold if you spray it when it's too hot.

I spray it first with the detailing rinse water, then spray with the engine cleaner. After that, I switch back to rinsing with the detailing rinse water.

I think what sometimes causes trouble is careless use of the full-power cycle. This setting may knock crucial ign./elect. stuff loose.

My 2 cents.

YES, Placo1 is correct. Use simple green and wipe off with a rag. Also some spots you will have to spray on the rag than clean off. Some areas are hard to remove dry grease, but with alot of elbow work you will get it clean to the color of your car. Mine is white and shines like brand new, even the cross member under the oil pan came out like new. Stay away from the electronics with the spray. Took me a week on and off to complete the first time. Now its just simple wipe offs. Do it!!!!!!