How to clean the engine bay

SquareWheels · 03-07-2021, 02:49 PM

I'm not a fanatic about keeping the car perfectly clean. I'm lucky that coming up on 2 years, the paint is still perfect. I took out my rugs this winter and used Weather Tech plastic mats (I live in New England and drive it year-round).

Spring will be here soon and I can wash it in the driveway soon.

Any tips on how to clean the engine bay? Especially thing never to do? Not looking to get it factory new, I rarely open the hood. Just looking to clean it up a bit.

Billfitz · 03-07-2021, 04:08 PM

I spray mine with diluted Flash Brown Royal, then rinse with water. Water won't bother anything so long as you don't use a pressure washer and use just what you need to get the detergent off. This does get it pretty much factory new.

Salty B. · 03-07-2021, 09:51 PM

Quote:

Originally Posted by Billfitz

I spray mine with diluted Flash Brown Royal, then rinse with water. Water won't bother anything so long as you don't use a pressure washer and use just what you need to get the detergent off. This does get it pretty much factory new.

The wheel cleaner? Seems kind of harsh, even diluted.

Billfitz · 03-07-2021, 09:58 PM

Nope, it's not harsh at all. You could even use it straight, but there's no need, so why waste it? I use a 3:1 water to Brown Royal mix for general de-greasing and cleaning, 1:1 for wheels. The only caveat is that it stinks to high heavens, so only use it outdoors, never in a garage.

328iX · 03-07-2021, 11:13 PM

Get any engine degreaser, or degreaser in general, purple power, super clean, simple green, etc.

I use simple green as its biodegradable and isn't so harsh.

Start off with a cold engine, soak it throughout with cleaner, let it sit for a bit, a minute or so, and with a soft bristle brush just agitate everything and rinse.

Don't let the degreaser dry, don't be afraid to hit anything, all connectors have waterproof seals, just don't sit in one place too long or soak anything.

Dry as much as you can with a towel, compressed air, etc.

Since degreaser is drying, hit all the hoses and plastics with a product to reinvigorate them. I use matte finish interior detailers such as Meguiars natural shine, that way they're not dry, and won't attract dust and dirt from being overly greasy. I apply with a microfiber so there's no excess.

chowser51 · 03-07-2021, 11:29 PM

I do Brown Royal 4:1 for a lot of things. In the winter, I will do my 2:1 mix on the wheels and the 4:1 on the paint! I will actually walk around the bottom of the car and spray it on. Then hose everything off before I start washing.

Billfitz · 03-08-2021, 07:43 AM

I've never tried it on paint, fearful that it might strip my sealer. But for everything else it's not just my go to, it's my only choice, because it's good for cleaning anything, and really inexpensive when you get it by the gallon and then dilute it.

chowser51 · 03-08-2021, 11:48 AM

my paint still beads like crazy. i only use it on the lower panels. haven't tried it on glass or higher. I'm trying out 303's graphene sealer. i know a 1:1 of brown royal will clean my concrete stains from my Subaru. lol

CajunBMW · 03-08-2021, 12:08 PM

I've had good luck with the Griot's garage engine cleaner. All the other good stuff above I follow. I first get leaves and other junk out, then I spray the cleaner on a cool engine, agitate the dirt or grease with a brush and or rags and then gently rinse off. I let it dry and then use the Griot's engine bay dressing. My engines stay clean and looking good for a long time. Seems to work well for me.

Pauloxxi · 03-08-2021, 12:34 PM

I don't do this often... only twice, I used GUNK Foam engine cleaner.
Just followed the instructions and worked fine.

muniz_ri · 03-08-2021, 02:04 PM

Quote:

Originally Posted by Pauloxxi

I don't do this often... only twice, I used GUNK Foam engine cleaner.
Just followed the instructions and worked fine.

I used to use Gunk on my Honda Civic back in the 90's. It did a hella of a job.

erickonphoenix · 03-08-2021, 02:09 PM

I found this guys video real helpful a few years ago

Orion4 · 03-08-2021, 04:33 PM

I just use your generic engine de-greaser on a cool/warm engine. Let sit for 5 minutes, then hose off with a medium strength spray. Been doing it for years. When I first started driving in 63, we used to make sure the engine was cold and wrapped the distributor in Saran Wrap. Water/condensation inside the distributor cap toasted more than one when I started it post cleaning!

03-07-2021, 02:49 PM	#1
SquareWheels Private First Class 119 Rep 178 Posts Drives: M550 Join Date: Jul 2019 Location: Tennessee iTrader: (0) Garage List 2023 M550i [10.00]	How to clean the engine bay I'm not a fanatic about keeping the car perfectly clean. I'm lucky that coming up on 2 years, the paint is still perfect. I took out my rugs this winter and used Weather Tech plastic mats (I live in New England and drive it year-round). Spring will be here soon and I can wash it in the driveway soon. Any tips on how to clean the engine bay? Especially thing never to do? Not looking to get it factory new, I rarely open the hood. Just looking to clean it up a bit.
	Appreciate 1 paulymu62.50 Tweet Quote

03-07-2021, 04:08 PM	#2
Billfitz Lieutenant General 8221 Rep 16,054 Posts Drives: '15 328iX GT Join Date: Jan 2015 Location: New Hampshire iTrader: (0)	I spray mine with diluted Flash Brown Royal, then rinse with water. Water won't bother anything so long as you don't use a pressure washer and use just what you need to get the detergent off. This does get it pretty much factory new.
	Appreciate 4 SquareWheels119.00 paulymu62.50 chowser512025.00 MacklinUSOB518.00 Quote

03-07-2021, 09:58 PM	#4
Billfitz Lieutenant General 8221 Rep 16,054 Posts Drives: '15 328iX GT Join Date: Jan 2015 Location: New Hampshire iTrader: (0)	Nope, it's not harsh at all. You could even use it straight, but there's no need, so why waste it? I use a 3:1 water to Brown Royal mix for general de-greasing and cleaning, 1:1 for wheels. The only caveat is that it stinks to high heavens, so only use it outdoors, never in a garage.
	Appreciate 0 Quote

03-07-2021, 11:13 PM	#5
328iX David 786 Rep 2,010 Posts Drives: 2015 328iX F31 Join Date: Nov 2018 Location: Temecula, CA iTrader: (0)	Get any engine degreaser, or degreaser in general, purple power, super clean, simple green, etc. I use simple green as its biodegradable and isn't so harsh. Start off with a cold engine, soak it throughout with cleaner, let it sit for a bit, a minute or so, and with a soft bristle brush just agitate everything and rinse. Don't let the degreaser dry, don't be afraid to hit anything, all connectors have waterproof seals, just don't sit in one place too long or soak anything. Dry as much as you can with a towel, compressed air, etc. Since degreaser is drying, hit all the hoses and plastics with a product to reinvigorate them. I use matte finish interior detailers such as Meguiars natural shine, that way they're not dry, and won't attract dust and dirt from being overly greasy. I apply with a microfiber so there's no excess. __________________ F31 Suspension guide & discussion
	Appreciate 1 floridaorange10126.50 Quote

03-07-2021, 11:29 PM	#6
chowser51 Colonel 2025 Rep 2,808 Posts Drives: F33 430 and F39 M35i Join Date: Feb 2009 Location: Cleveland, OH iTrader: (3) Garage List 2018 BMW 430i xDrive [0.00]	I do Brown Royal 4:1 for a lot of things. In the winter, I will do my 2:1 mix on the wheels and the 4:1 on the paint! I will actually walk around the bottom of the car and spray it on. Then hose everything off before I start washing.
	Appreciate 0 Quote

03-08-2021, 07:43 AM	#7
Billfitz Lieutenant General 8221 Rep 16,054 Posts Drives: '15 328iX GT Join Date: Jan 2015 Location: New Hampshire iTrader: (0)	I've never tried it on paint, fearful that it might strip my sealer. But for everything else it's not just my go to, it's my only choice, because it's good for cleaning anything, and really inexpensive when you get it by the gallon and then dilute it.
	Appreciate 0 Quote

03-08-2021, 11:48 AM	#8
chowser51 Colonel 2025 Rep 2,808 Posts Drives: F33 430 and F39 M35i Join Date: Feb 2009 Location: Cleveland, OH iTrader: (3) Garage List 2018 BMW 430i xDrive [0.00]	my paint still beads like crazy. i only use it on the lower panels. haven't tried it on glass or higher. I'm trying out 303's graphene sealer. i know a 1:1 of brown royal will clean my concrete stains from my Subaru. lol
	Appreciate 1 Billfitz8220.50 Quote

03-08-2021, 12:08 PM	#9
CajunBMW Lieutenant Colonel 1289 Rep 1,641 Posts Drives: BMW 340i and X1, Chrysler Van Join Date: Mar 2019 Location: Shreveport, LA iTrader: (0)	I've had good luck with the Griot's garage engine cleaner. All the other good stuff above I follow. I first get leaves and other junk out, then I spray the cleaner on a cool engine, agitate the dirt or grease with a brush and or rags and then gently rinse off. I let it dry and then use the Griot's engine bay dressing. My engines stay clean and looking good for a long time. Seems to work well for me.
	Appreciate 0 Quote

03-08-2021, 12:34 PM	#10
Pauloxxi Captain 339 Rep 660 Posts Drives: 2014-320Xi / 2017-330Xi Join Date: May 2010 Location: Northwest iTrader: (0) Garage List 2017 BMW / 330xi [0.00] 2014 BMW / 320xi [0.00]	I don't do this often... only twice, I used GUNK Foam engine cleaner. Just followed the instructions and worked fine.
	Appreciate 0 Quote

03-08-2021, 02:09 PM	#12
erickonphoenix Lieutenant 1722 Rep 535 Posts Drives: 2014 Gray 328xi Touring Join Date: Jun 2015 Location: Houston TX iTrader: (0)	I found this guys video real helpful a few years ago
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03-08-2021, 04:33 PM	#13
Orion4 Lieutenant Colonel 478 Rep 1,568 Posts Drives: 2013 335i Sport Line Sedan Join Date: Aug 2009 Location: Melbourne, FL iTrader: (0)	I just use your generic engine de-greaser on a cool/warm engine. Let sit for 5 minutes, then hose off with a medium strength spray. Been doing it for years. When I first started driving in 63, we used to make sure the engine was cold and wrapped the distributor in Saran Wrap. Water/condensation inside the distributor cap toasted more than one when I started it post cleaning!
	Appreciate 0 Quote