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Dirty Engine Compartment


Charter Member
SM 2003
Full Member
Jan 26, 2002
Los Angeles, California
One thing I noticed about my Av is that the engine compartment gets dirty very often. I originally noticed that there was a gap between the hood and the top of the radiator cover panel.

I installed a nice rubber gasket under the front portion of the hood. It sealed up the gap perfectly.

The engine compartment is still getting dirty and so is my FIPK filter.

I think that the design of the vehicle is such that it is sucking up road dirt through the bottom.

Any thoughts?
Seriously, consider getting the "sock" cover for the K&N - I am putting mine on today - I spend half my time driving through construction zones in Houston and dust is everywhere. :cautious:
Does anyone here have an idea of what to clean the engine compartment with? On my Dodge, I used Simple Green, but I noticed after a few years that it was taking the paint off.
Light detergent and then follow up with Stoners more shine less time......
I should really write this up for CAFCNA Magazine but I've been cleaning engines this way for over ten years and it works 100%.

1) Drive your Avalanche around until your engine temperature is running at normal, around 190 degrees. This works best if you do this during warm weather.

2) Go to a "do it yourself" carwash. You'll need quarters for two squirts.

3) Leave the engine running and open the hood. Using the pressure hose lightly mist (not full pressure) the entire engine bay while it is running. This should only take about a minute. Then go to the wheel cleaner if that is an option and spray the engine bay with the wheel cleaner. Be careful not to get the cleaner on the body panels. Than spray the inside part of the hood with the soap. If you still have time mist the engine again so that the components are wet. Make sure to walk around and get at different angles, lots of nooks and crannies in the Avalanche engine bay.

4) Take a bottle of Simply Green and spray down the engine bay. Spray everything, including the hood liner. After that close the hood - leave the engine running.

5) Sit for about five minutes. The engine should have steam coming off of it and you should smell the Simply Green - don't sit so long that the combination dries out.

6) Go ahead and load up on quarters again. Put the setting on rinse water. Spray down the engine bay at pressure. Stand back so you don't damage components, don't blast the alternator to see how much it can take and watch the air intake. After a quick blast of the engine bay do the inside of the hood first (because the rinse will drip down into the engine) and then do the rest of the engine bay. Again be sure to get any nook and cranny you can find, walk around at different angles.

7) Take a towel and dry down the edges of the hood, the fan shroud, the air cleaner and the top of the fuse junction under the hood. Be careful not to get the towel caught in spinning engine components.

:cool: Drive home.

9) Let the engine bay cool down, about an hour is good. It helps to leave the hood open. Take your favorite protectorant (I've found EagleOne spray works GREAT) and treat the plastic/rubber components under your hood (not the belts!). Wipe down any water spots, use a detailing mist if your anal about scratches. If you leave the hood open your hood liner shouldn't water mark. If it does it dried to fast or you left too much soap in it.

Although this sounds long it really isn't. The whole process at the car wash shouldn't last any more than 12 to 15 minutes. The final wipe down unless you really detail the engine bay will only take another 10 to 15. I'm doing my Avalanche once every six months and I'm planning on doing my wife's Thunderbird this weekend.
Great instructions Chief - as you can imagine my engine compartment is a little dirty and needs a good cleaning. :0:
I think I remember another member that used pond water to rinse his AV's engine compartment, undercarriage, cab, ect. But his method cost more than just a few quarters. Great post Chief. I've followed almost the same routine myself for years. Really like a clean engine compartment. However, I have been known to get carried away before trying to get everything spotless under the hood and ended up shorting out a sensor or two over the years. Just have to learn to use a little common sense and be cautious around the electrical components.
Thats whats nice about having a pressure sprayer at home. Can kick back between steps and enjoy your fav adult beverage.
i always use simple green, this stuff is great. what i do is just open the hood and spray it all over everything, then just hose it off. It leaves it looking like the day chevy built it. i recomend this method.

Alex :B:
Same here Alex Plus i love the smell of Simple Green. I usually wait for it to dry then apply a light coat of tire dressing but don't get on belts. This does attract dust so if your in a dusty area omit the tire dressing.
et me add that once you get the compartment clean just rum a damp rag once or twice a week where ever your hand can reach that should do it of course easier said than done.
Wow Chief - you seriously use a pressure washer under the hood?? :eek: I don't think I could get myself to do that... I'll drill holes in my roof for a rack, no problem - but I could never get used to doing this.

I've heard in at least one of my manuals never to use high pressure water to clean an engine. All of my motorcycle manuals say to never use it in/near/around the engine, and especially keep it away from seals.

ONCE I rinsed off my '70 Olds engine, after an oil line blew about two quarts of oil all over the bay.... but that was low pressure water out of a hose.... and that was one of those nice old engines you could fix with a rock and a stick. ;D

I guess if you never had problems, then this is the best / easiest way to go. :)
Was that '70 Olds engine a 455? I used to fry eggs on mine. It ran a little hot. >:D It was in a '68 Olds 88. Good car for a teenager >:D
I had a regular Cutlass with the 350 "Rocket" :rolleyes: ... The 442's and the Toronado's had 455's, right?

I had a 455 all torn down in my cellar, all ready to rebuild... I shopped around, and the best price I could find would be about 4K - too much for myself back then. :6: And nevermind with the Mondello stuff I wanted to stuff in there!
Just a general question, when the car is turned on, will water or any solutions damage any of the electrical system? such as the alternator which is sitting there exposed. Or are you only targetting specific areas? I have mud splashed all over the inside of the hood, even on the ceiling of the hood itself, and want to know the best way to approach this..
Cid I am always careful around electrical components.
Does anyone use gunk?, i use it after every oil change while engine is warm, but not hot. Spray it down and let it sit a few moments and rinse off real good. Get a five gallon bucket of water mixed with regular dish detergent and pour over entire engine and rinse again.
Start engine and let run a while to dry things out.
After all is dried i usually spray down with tire dressing and close hood back and start and let run till hot to set dressing, like someone mentioned above if you drive in a dusty area leave out the tire dressing because it will suck it up. about every 6-8 weeks for me and stays shiny unless i hit a dirt road a few times then it gets all dusty and back to the field to do some more cleaning.
.02 cents that the guys at the dealer ship gave me on info that they use on used cars to prep them for sale.
Greased Lightning seems to work well. Spray on, let set a few minutes and rinse off. Blow it dry with a leaf blower.
Did a modified version of the Chief's engine compartment clean up this evening. I did some nasty damage using high pressure hose on my wife's '91 Capri a few years ago, so I am a little gun shy about doing this at the car wash.

Here's my approach for those concerned about water getting where it shouldn't be.

First, I use a flower watering wand to wet the engine compartment. Most of you have seen these. That have a head about 2" in diameter and often are mounted on the end of a 2' long arm with a slight bend. They're low pressure and the extended arm makes it easy to get to all the nooks and crannies. Just like the Chief's program, I have the engine running while I do this. Get it good and wet (except for electrical areas and the alternator) and then give it a good dose of Simple Green. Let it work for a few minutes, then rinse thoroughly.

At this point I get real crazy about making sure that the fenders don't have any of the hosed out solution on them. Then I start wiping down. First to dry, then each surface gets its own treatment. Hood edges and inside fender wells get Meguiar's Spray Mist Detailer (or similar wipe-and-shine product), Flat black and aluminum surfaces get Wax Shop's Bumper Black (or similar) and hoses, fan shrouds, and other plastic or rubber surfaces get Meguiar's Rubber and Vinyl Cleaner and Conditioner (or 303 or ArmorAll, whatever you prefer).

I have used this method since 1993 (last time I did it at the car wash) and haven't had a single problem with electrical malfunctions.
My Sunday project... :eek:


More to follow...

Murman :cool: