How to safely clean engine?
Le Mans Master
Joined: Apr 2012
Posts: 7,814
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From: Brighton MI
For an engine that is already pretty clean like yours, I would use Simple Green...I use it on all mine. You can hose it off without any issues, just don't go crazy with the water especially around alternator and electrical connectors. Blow dry. 
Melting Slicks
Joined: Nov 2014
Posts: 3,399
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From: Havre de Grace Maryland
Before you decide to use any water in the engine compartment, I suggest reading all the electrical anomalies the C5 has. After I did, I decided not to use any water for spraying and used many rags (damp and dry) to wipe my engine compartment clean.
Burning Brakes
Joined: Jun 2017
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From: Wichita Falls Texas
Brushes, compressed air, rags, tire shine stuff, time, patience and elbow grease.
I ruined some electrical parts on an engine many years ago using soap and a water hose so never again.
Once you get it clean it's pretty easy to keep it that way.
Good luck!
I ruined some electrical parts on an engine many years ago using soap and a water hose so never again.
Once you get it clean it's pretty easy to keep it that way.
Good luck!
Le Mans Master
Joined: Sep 2013
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From: Wisconsin
A friend of mine used soap and a hose to clean his engine compartment. He had to flatbed his car to a shop to get it started.
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This is what I do to keep my engine clean. May take a little longer, but no worries about getting water where it shouldn’t be.
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I've seen literally hundreds of C5/C6 engines pressure washed with steam with no negative effects.
Basically, go to the car wash and do whatever the hell you want. Period.
Basically, go to the car wash and do whatever the hell you want. Period.
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Since it's already clean, I would just wipe done with rags.
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Burning Brakes
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Le Mans Master
Joined: Sep 2013
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From: Wisconsin
Bad advice. I have seen several threads here about getting engine wet and having problems and like I said a friend of mine(actually my dentist) sprayed his engine bay, the car would not start and he had to have it trucked to a dealership.
Last edited by JR-01; Apr 30, 2018 at 03:43 PM.
Melting Slicks
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it's ok to use water, just make sure to immediately dry it off before you start the car
Okay do what you want with yours. I'll see another 1000 blasted without problems.
Zen Vet Master Level VII
Joined: Mar 2016
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From: Southlake, TX
So here is a couple of visuals for you. I did this on my 1989 with the L98 engine, but you get the idea. I cleaned the engine, frame, radiator etc with no problems. The ole 89 popped immediately and I ran the engine till all the water was dry.
Mask and cover any exposed electrical. I sprayed on regular car wash soap, but the suggestions for Simple Green are spot on. I used a brush and towel to get in and around tight areas. I used hose to "trickle" water for a rinse and as mentioned NEVER blast your engine with high pressure.
I was super happy with the results. I did the same for my LS6 and it came out great.
Mask and cover any exposed electrical. I sprayed on regular car wash soap, but the suggestions for Simple Green are spot on. I used a brush and towel to get in and around tight areas. I used hose to "trickle" water for a rinse and as mentioned NEVER blast your engine with high pressure.
I was super happy with the results. I did the same for my LS6 and it came out great.
Last edited by billschroeder5842; Apr 30, 2018 at 05:17 PM.