Engine Clean

alpinecrick said:

Spray wash the engine when it's running--have been washing the engine bay of my GMT400's for 30 years, at the car wash or with one of my pressure washers. I wash the engine bay almost every time I wash the truck. Keeping the engine bay clean goes a long ways towards keeping plastic and rubber parts from deteriorating. Half the time my engine bays are cleaner than my interiors....

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Early '90's lesson for me...1969 Cougar XR7. Car wash. Engine off. Washed the engine bay. Spent next 2 hours trying to get it started.
Leave the engine running on everything since then. And drive it a good 15 minutes afterwards to make sure everything is dry. Never an issue again.

1ton-o-fun said:

Early '90's lesson for me...1969 Cougar XR7. Car wash. Engine off. Washed the engine bay. Spent next 2 hours trying to get it started.
Leave the engine running on everything since then. And drive it a good 15 minutes afterwards to make sure everything is dry. Never an issue again.

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This is why WD-40 is your friend. A quick blast inside the distributor cap and you are on your way,

Oven cleaner works great and is cheaper. Don't leave it on aluminum parts very long.

I like to use the Foamy Engine Brite and a garden sprayer to rinse the engine. Much more controllable than a pressure washer.

I spray WD-40 liberally afterwards an wipe it off of everywhere I can reach. Makes the plastic parts look nice and they seem less brittle too. Not sure how much of that is imagined though!

I have two commercial cold water portable pressure washers that run 3200psi/3gpm and 3600psi/4gpm respectively. Although nothing beats warm water, lots of pressure and volume goes a long way. Even a little Costco electric 500psi pressure washer will work at home. Regular ol’ cheap car wash soap, using a pump up weed sprayer and liberally spraying soapy water on everything under the vehicle, then using the pressure washer will knock most of greasy/oily gunk off.
I have been known to jack up my trucks or vans, remove the wheels, skid plates, and any shields in my way, and lay under the vehicle and wash it. Especially if I’m going to work on them. Once it’s clean keeping them clean is a whole lot easier. Obviously, I don’t do this during the winter……..
If I spend time in the mud, driving the truck in the rain or slushy snow will blow most of the mud off. Then wash it. When I go to the car wash I spend more money reaching underneath and washing than I do washing the shiny side.
This does go a long ways to making plastic and rubber parts last longer, and keeping rusting of the metal parts at bay. I’ve seen this with agricultural equipment.

If the engine is hot then leave it running. It won’t crack the exhaust manifolds or possibly any other iron parts. It also will keep ignition parts dry.

ChrisFix actually has a great video on engine bay cleaning.

Finn said:

I have a stock 1990 gmc c1500 5.7 engine it has gotten really dirty over the past few weeks and wanted to know how I’m able to clean such an on old engine bay or can I just spray it down?

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What I say. Don’t use a pressure washer, high pressure water is a great way to force water somewhere it shouldn’t go. I use a pressure washer in my engine bay on everything except the engine and electrical. All you need is a couple spray bottles, one with hot dawn dishsoap water and one with normal water, a few brushes(kitchen brush, tooth brush, you pick) and use the water hose on really low to rinse things off. What you really need is TIME. You can half-butt the cleaning, but then you just shouldn’t do it at all. My brother took apart my dads powerstroke 7.3 and spent around 8 or 9hrs cleaning EVERYTHING in the engine bay. Compressed air works good for drying it off, you can also use a vacuum switched around to blow and not suck, a leaf blower also works. That does have a chance of pushing water where it shouldn’t go, but not nearly as much as a pressure washer.

A much cheaper solution is to use Purple Power in a garden sprayer. With a cold engine put plastic bags over your cap, ecm, and alternator.
Wear a long sleeve shirt and gloves. Safety glasses or better yet a face shield. Start at the bottom and don't inhale any over spray. Hose everything down and let it soak 15 mins. Then wash everything down with a garden hose, not a pressure washer. Remove the plastic bags and start the engine immediately. Let it get up to operating temp or better yet take it for a spin.

I see many here know, but lots of people don't know that WD40 is for water displacement, not a lubricant. learned that the hard way after a few engine bay washings at car washes, then time spent trying to get the car started, if it didn't wipe out the rotor sparking all over the place in the cap.

1madmouse said:

I see many here know, but lots of people don't know that WD40 is for water displacement, not a lubricant. learned that the hard way after a few engine bay washings at car washes, then time spent trying to get the car started, if it didn't wipe out the rotor sparking all over the place in the cap.

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Even better, put a dab of dielectric silicone on every contact and around connector seals.

WD-40 is a great engine cleaner, all by itself. ( You can also wash your hands with it, and it cleans grease)..... I used one of those hose/spray tips that you can adjust , but not flooding your engine area. You can aim it close, and the spray is still fairly strong enough. I use the fine tip on the top.

Then I use Gunk foam engine cleaner down lower, around the heavy ugly areas.