Engine cleaning

Im going to be cleaning the engine in the next few days, ill be getting a few cans of that heavy duty engine degreaser. i know you spray it on and let it sit for a few hours, but what should i do to prepare eveything, i know i gotta cover up the alternator, wiper motor, battery, intake, carb, and the ac motor and relays. is it ok for everything else to get wet?

i would be careful if i were you. I once decided to clean my engine with the garden hose. I thought i was being careful but apparently not enough because my ac/heat fan wouldnt turn on for the longest time after. Luckily it was just the resistor so thats one thing i'd stay away from. I'd say be careful with the electrical components in general when you clean it.

im gonna cover up all the electrical stuff, i found directions to paste into here if anyone needs a reference:
To soften the grease and grunge collected on your engine compartment, start the engine, let it warm up for a few minutes and shut it off. The proper cleaning temperature of the engine is warm but not hot. If you can just hold your hand to the engine without burning it, then it is warm enough to clean. As the engine cools to proper temperature, use the time to cover the few openings on the motor that dislike ingesting water. The air intake/air filter, the distributor, the coil and the oil dipstick/breather are among the few sensitive areas.

Use plastic Baggies and rubber bands to cover the air intake/air filter(s) and the distributor/coil. Place a double layer of Baggies over the air intake and secure with a couple of rubber bands. Use a pair of two-gallon size Baggies to cover the distributor and plug wires around the distributor cap. This may be difficult to seal, but the idea is to prevent significant amounts of water possibly shorting out the distributor. If the cap is in good condition, it will be waterproof, so this is only a preventative measure. The coil is also waterproof, so Baggies are again a preventative measure. Check the tightness of the oil filler cap, the power steering filler cap, windshield washer fluid cap, oil dip stick, battery filler caps and all other engine compartment opening caps and secure baggies over them with rubber bands.

Now that your engine is warm and sealed, spray the entire engine/engine compartment with a quality, non-petroleum based degreaser. Try to start from the bottom and work up. This way you dont have the degreaser dropping on your face as you clean the underside areas. My two favorite citrus based engine cleaners are P21S Total Auto Wash and Wurth Citrus Degreaser. I find that either of these two citrus products will clean thoroughly and not harm the paint or finish of the aluminum components and are biodegradable. One note of caution, all degreasers will remove your nice coat of wax. If you get the engine cleaner on the waxed areas, plan on rewaxing. Allow the degreaser about 3-5 minutes to work and then use a 100% cotton towel or a SOFT brush to GENTLY agitate the heavily soiled areas. Respray and rebrush any areas that need additional cleaning. Once the entire engine/engine compartment has been cleaned, rinse thoroughly with water. There is a debate as to the optimum force of spray to rinse the degreaser. Some say a gentle spray is all that is necessary, while others advocate the use of a high-pressure spray. Use your common sense. The stronger the spray, the more likely you will get water in sensitive parts. If all areas are properly protected, you should have no problems with a stronger spray. If any areas need additional cleaning, repeat as necessary.

Once the engine/engine compartment is clean, immediately remove all of your plastic baggies/rubber bands. Dry any puddles and aluminum parts with a soft, 100% cotton towel. Use paper towels to thoroughly dry the battery (if it is in the engine compartment). Start the engine and allow it to warm up. This will dry the rest of the engine and evaporate any moisture that may have collected in sensitive components.

I am not a fan of steam cleaning. I have found that the high pressure steam has a nasty tendency to infiltrate the electrical connections and cause havoc. The modern engine has numerous sensors that continually feed precise information to the computers. If steam penetrates these sensors and corrodes the electrical connections, electrical signals may be disrupted and cause the engine to run erratically or not at all. The amount of time it takes to disassemble, clean and reconnect all these sensors is incredible.

Just to let you know, theres an area on the driver and passenger side under the hood where rust holes tend to form and aren;t always visible. I'll take a picture once it stops raining here because if you plan on spraying down the engine bay area, this hole forms just about exactly above the fuse box, which might not be fun to get wet:grinno: .

I know i got some rust on the firewall behind the glove box, but ill look out for the other side too

my car caught on fire when i used that degreaser stuff when i went to start it back up, luckily i had water hose by me and it was already on....

Many engine degreasers are flammable, and that's another reason to stress a good thorough rinsing; not only to get the engine clean, but free from flammable chemicals where they shouldn't be.

Indeed, i dont think the cleaning worked that well, then again like i said i diddnt expect a 25 year old engine to look brand new lol i may do it again though

simple green in a pressure washer used with restraint can work wonders

Remember, after 25 years of minimal underhood tidy-ness most likely will result in chipped, flaking, dull engine and component paint, not to mention the rust that may have formed under that grime (the non-oil based grime). After cleaning my 305 back in the day I took off and repainted the valve covers. That made a whole heck of a difference. I used chevy engine orange, but even a nice coat of high temp gloss black will help to make that engine look nice. Of course the cleaning should always come first. Nothing as pointless as painting over dirt.

mine came clean. but its just kinda dull now and there is some surface rust of course in a few places