Pressure wash Engine
Race Director
Joined: Feb 2003
Posts: 16,475
Likes: 270
From: Kingman AZ
Cruise-In VII Veteran
Cruise-In VIII
St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16
In one of my Gordon Killebrew classes he said that is ok to soak a warm (not hot) engine with degreaser/cleaner and then to rinse it off with a gentle spray of water. Non-LT1/4 engines only.
Pro
Joined: Dec 2010
Posts: 704
Likes: 1
From: Shillington PA
When I worked in the body shop, I used to degrease and steam clean, high pressure, etc like a ****... If it came in, I went OFF on it. BAck then I did not know what an OPTI was. If I knew then what I know now..... ugh.
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Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Words don't really exist to fully convey how bad an idea it is to pressure wash any modern computer controlled engine. All those "weather tight" connections are meant for water splashed on them, not sprayed at 2000psi.
If you have an LT1, as the others have mentioned, it would be a miracle if you didn't destroy the opti.
I've pressure washed under the hood of my '74 pickup truck, but then again I can easily see all the wiring and keep the water away from it.
If you have an LT1, as the others have mentioned, it would be a miracle if you didn't destroy the opti.
I've pressure washed under the hood of my '74 pickup truck, but then again I can easily see all the wiring and keep the water away from it.
Burning Brakes
Joined: Aug 2009
Posts: 950
Likes: 8
From: Bowling Green Ohio
Melting Slicks
Joined: Jan 2009
Posts: 3,482
Likes: 196
From: folsom california
I used to pressure wash EVERYTHING...and for somethings, non eletrical like suspensions, undercarriages, its still the best way to go. with all that said now I use brake spray degreaser, brake cleaner, and a ton of industrial grade paper towels. You can probably get away with pressure washing an engine compartment if you stay away from and or protect electrical components with plastic baggies, but given how tight a c4 engine compartment is, this may not be possible. If you do insist on a pressure wash do it on a hot dry day and then drive that car long enough and far enough to allow any trapped water to evaporate.
Safety Car
Joined: Aug 2008
Posts: 4,344
Likes: 48
From: San Marcos CA
Besides the obvious- avoiding the distributor/optispark/alternator- never spray a hot engine. Good way to crack the potentiometer in the TPS sensor or who knows what else...wait for it to cool down to where it is merely warm before washing.
Le Mans Master
Joined: Oct 2004
Posts: 7,706
Likes: 485
From: Everett WA
C4 of Year Finalist (appearance mods) 2019
There are no Dos and there is only one dont. DONT DO IT
Use some engine degreaser and some soft brushes and some rags or some simple green and some brushes then gently rinse off using a garden hose with no sprayer attached so that you can control where the water goes. Nothing on the front of the engine.
Use some engine degreaser and some soft brushes and some rags or some simple green and some brushes then gently rinse off using a garden hose with no sprayer attached so that you can control where the water goes. Nothing on the front of the engine.
