How do you clean your engine bay?

dud

Diamond Member
Feb 18, 2001
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I am getting ready to do some major PM to the wife's 07 Civic (MT fluid, refresh coolant/hoses, etc.). The last thing I want to do is to clean out the engine bay. In the past I have tried Simple Green (works great but damages aluminum engine parts and dulls paint), Foamy Engine Brite and even Dawn dishwashing liquid. I am leaning towards using the foamy stuff becuase it does not seem to do the damage that SG does.


How do you clean your engine bay?
 

JulesMaximus

No Lifer
Jul 3, 2003
74,586
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I haven't even opened my hood in probably a year and I have never cleaned the engine of any car I've owned ever in more than 30 years of driving and over 8 different cars and half a million miles.

Unless it is a show car, don't waste your time.
 
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Yuriman

Diamond Member
Jun 25, 2004
5,530
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I use a high pressure nozzle on my hose and some liquid detergent; Dawn seems to work best. It's not a bad idea to cover your alternator with a grocery bag before soaking it down, I've heard.
 

Raizinman

Platinum Member
Sep 7, 2007
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I would recommend against it. Too much a possibility of getting water into harnesses and other places water should not be, especially if using a high pressure nozzle. Instead, find a Groupon or similar type coupon and let someone else be responsible for engine damage should it happen.
 
Mar 10, 2005
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if it's not a show car, why bother? the engine bay is literally covered in electronic equipment that if working is best left alone and not blasted with solvents and high pressure washers.
 

rsutoratosu

Platinum Member
Feb 18, 2011
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lots of people cover electronics (alt and others) and spray simple green & scrub and hose off..
 

Squeetard

Senior member
Nov 13, 2004
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I get floor degreaser from my local janitorial supply company, mix it 50/50 with water in a spray bottle, spray it on, leave it for a few minutes and then hose it off. Works great. Don't let it dry and do not do this to a warm or hot engine.
 

ManyBeers

Platinum Member
Aug 30, 2004
2,519
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Lots of people have to have their vehicle towed to a garage or dealership because after cleaning the engine; it won't start or runs rough now.

Baloney. I have never had a problem with any of my vehicles. I just did my Tahoe's
engine bay at the local coin-op wash as I do at least once a year and it was fine. For
a 2001 with 160,000 miles on it the engine bay looks like new. I never use high pressure settings on the hose though.
 

JCH13

Diamond Member
Sep 14, 2010
4,981
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lots of people cover electronics (alt and others) and spray simple green & scrub and hose off..

Simple Green is really sad to use in engine bays. It can dissolve the carbon brushes used in some alternators and starters. Covering stuff with a bag or plastic is nice, but isn't guaranteed to stop intrusion.

Baloney. I have never had a problem with any of my vehicles. I just did my Tahoe's
engine bay at the local coin-op wash as I do at least once a year and it was fine. For
a 2001 with 160,000 miles on it the engine bay looks like new. I never use high pressure settings on the hose though.

Just because you haven't had any issues doesn't mean that the risk isn't present. I washed the engine bay in my Miata (mist setting on a garden hose only) and some water got trapped in the valve cover valley and after the car warmed up, then cooled off, after some driving the water got sucked into the spark plug wells and made ignition really sad, to the point where the car hardly ran.

I don't bother washing my engine bay at all anymore. If I was going to, though, I would use a cleaning wipe (like an ArmorAll wipe, but without the silicone-based goop) or a damp rag/paper towel to wipe down any dirty surfaces.
 

ballmode

Lifer
Aug 17, 2005
10,246
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First off I live in Kentucky, we get snow/salt but maybe only 2 weeks a year. I tend to clean the engine bay once a quarter during a carwash.

First I gently get the engine bay wet, avoiding the battery and spark plugs. Then I take simple green, dilute it, and let it sit for a minute or two. I then take a brush and scrub the plastics, and anything I can get my brush to. Gently rinse it off and let it sit out in the sun for an hour or two to fully dry.
 

WilliamM2

Diamond Member
Jun 14, 2012
3,007
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Simple Green is really sad to use in engine bays. It can dissolve the carbon brushes used in some alternators and starters. Covering stuff with a bag or plastic is nice, but isn't guaranteed to stop intrusion.



Just because you haven't had any issues doesn't mean that the risk isn't present. I washed the engine bay in my Miata (mist setting on a garden hose only) and some water got trapped in the valve cover valley and after the car warmed up, then cooled off, after some driving the water got sucked into the spark plug wells and made ignition really sad, to the point where the car hardly ran.

I don't bother washing my engine bay at all anymore. If I was going to, though, I would use a cleaning wipe (like an ArmorAll wipe, but without the silicone-based goop) or a damp rag/paper towel to wipe down any dirty surfaces.

That used to happen on my Protege too. Had to blow our the spark plug wells with compressed air to get it to run. Poor design, and poor seal in my opinion. Never had that issue with any other car of motorcycle I've owned.
 

Railgun

Golden Member
Mar 27, 2010
1,289
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Put a bag over the battery and alternator, soak it with gunk or other engine degreaser, hose down later. Let it dry for a good hour.
 

Raizinman

Platinum Member
Sep 7, 2007
2,355
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Put a bag over the battery and alternator, soak it with gunk or other engine degreaser, hose down later. Let it dry for a good hour.

What about the plugs? Plug wires? Coil(s)? Distributor (depending on year), Crank sensor? and engine wiring harness? What about the person who hoses down his hot engine with cold water? Many cars have a power block and or fuse block for which water can harm. You over general statement can cause people damage should they follow your advice.
 

NutBucket

Lifer
Aug 30, 2000
27,155
635
126
I spray simple green, wipe down areas that are easily accessible and hose everything off. No issues yet through many cars and many years.

I've heard steam is what you really want to avoid as moisture can end up condensing in places it shouldn't.
 

Railgun

Golden Member
Mar 27, 2010
1,289
2
81
What about the plugs? Plug wires? Coil(s)? Distributor (depending on year), Crank sensor? and engine wiring harness? What about the person who hoses down his hot engine with cold water? Many cars have a power block and or fuse block for which water can harm. You over general statement can cause people damage should they follow your advice.

Common sense doesn't really win it seems.

Do you cover you plugs when it rains? :rolleyes:

To each their own. If they can't comprehend, or extrapolate that they should cover sensitive parts...they shouldn't be doing it in the first place.

Sue me.
 

7window

Golden Member
Nov 12, 2009
1,533
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Common sense doesn't really win it seems.

Do you cover you plugs when it rains? :rolleyes:

To each their own. If they can't comprehend, or extrapolate that they should cover sensitive parts...they shouldn't be doing it in the first place.

Sue me.


The rain is not a direct hit. The hood shields the rain as oppose to spraying it with water directly. I completely agree that sensitive part should be covered.
 
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slag

Lifer
Dec 14, 2000
10,473
81
101
I leave the engine running, spray purple power on stuff, and then wash it off. Follow up with a silicon spray. I use stoner trim shine and it really makes the engine and all hoses/wires/plastic and metal shine.