And around here the trunk jambs fill with pine straw and pollen. It all cakes up and starts to rot.
Or, like on this Suburban, it leads to other damage. Rear glass was in horrible shape.
Scotty don't like clean engines?
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Or, like on this Suburban, it leads to other damage. Rear glass was in horrible shape.
There's one good reason to clean the engine. If you take it to a mechanic for repairs, they'll see a clean engine and everything is shiny, you have a better than average chance of the job being done right. It's psychological. If the customer keeps the engine this clean, obviously, he's detailed oriented. I've done that with my 03' Matrix and each time the mechanic has mentioned how clean the engine bay was.
WOW
I clean open mechanical areas such as the door hinges, latches, etc. or seals to the interior. I clean painted areas because that is a thin coating that can degrade. I clean rubber before applying protectant, then let it get dirty long term again.
Corrosion on an engine bay because not cleaned? Hasn't happened to mine nor have I read of an epidemic of it for other vehicles, considering the average person does not clean their engine bay.
Easier to work on is mostly psychological. I've not once gone into a repair and thought Oh noez what ever am i gonna do, DIRTZ. lol
I'm not advocating letting leaks go unrepaired, but if a mechanic isn't going to do as good a job because the engine wasn't washed, yet again another example of a reason to find a different mechanic if not DIY.
If you go to a used car lot, do you expect to see a dirty engine bay. Not hardly. Somebody cleaned it.
manicrodder
$50 site donor 2022
Last time I used a citrus APC and just open hosed it. Came out pretty good.
I wash my engines and undercarriages weekly, otherwise it gets horrible with all the dust in the air.
First deal of business is to use compressed air to blow off all the dust, and then I'll cover all sensitive components. Since I don't have any oil leaks or other funny business going on, there's no need for a degreaser. I'll liberally use a foam cannon and use a set of brushes and microfiber towels to go over everything before rinsing with high flow/low pressure water. Then comes the hardest part, which is blow drying everything with compressed air (especially ignition coils, electrical connectors, battery terminals, belts, bolts, etc.) and going over the entire engine bay with dry microfiber towels. At this point, I'll also wipe down sensitive components like the alternator with a wet microfiber dipped in soapy water, or use a wet brush followed by a towel if it needs it. I don't want it to be shiny or anything, just clean. Any of that shiny stuff, and everything will look worse than I started off with within minutes.
I can, however, see his point about not washing the engine bay. You won't find many people who'll go over everything with a fine comb and once water gets into things like ignition coils, that's when disaster strikes.
First deal of business is to use compressed air to blow off all the dust, and then I'll cover all sensitive components. Since I don't have any oil leaks or other funny business going on, there's no need for a degreaser. I'll liberally use a foam cannon and use a set of brushes and microfiber towels to go over everything before rinsing with high flow/low pressure water. Then comes the hardest part, which is blow drying everything with compressed air (especially ignition coils, electrical connectors, battery terminals, belts, bolts, etc.) and going over the entire engine bay with dry microfiber towels. At this point, I'll also wipe down sensitive components like the alternator with a wet microfiber dipped in soapy water, or use a wet brush followed by a towel if it needs it. I don't want it to be shiny or anything, just clean. Any of that shiny stuff, and everything will look worse than I started off with within minutes.
I can, however, see his point about not washing the engine bay. You won't find many people who'll go over everything with a fine comb and once water gets into things like ignition coils, that's when disaster strikes.
Grounds, connectors, etc. all corrode faster when moisture is present. Dirt holds moisture longer than a clean surface.
Most engine bays are also not fully painted. Cleaner is always better.
Connectors are supposed to be sealed. If they are not, spraying water in to clean is the problem, not the solution. Solution being replace connector, or just seal, or dielectric grease.
Grounds, eventually can be a problem but it is not an epidemic and easier to fix that than keep washing an engine bay which brings its own set of risks.
No, cleaner is not always better. It seldom makes any difference except for a lot of time wasted on vanity. If that's your hobby, then it's a different matter. Hobbies don't have to make sense.
Show in the average vehicle maintenance schedule where "clean engine bay" is, or how it applies to warranty. Quite the opposite, vehicles are designed specifically to function correctly without cleaning the engine bay. Obviously this does not consider extreme cases, like a rat's nest, bee colony, off-roading mud, etc.
Considering your username has VW in it, there is obviously an exception for air-cooled engines, just as there is a need to keep radiators clean for liquid cooling.
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JTK
$100 Site Donor 2025
I try to keep my engine bays looking nice and clean because it makes me feel good. I give them a gentle wash and wipe to get them clean and they generally stay that way. I've been doing that since the 1980s.
In terms of mechanics, watch any of the big players on the u toob and they couldn't care less about a clean engine bay. SMA, Watch Wess Work, Scanner Danner, Scotty etc..etc..
In terms of mechanics, watch any of the big players on the u toob and they couldn't care less about a clean engine bay. SMA, Watch Wess Work, Scanner Danner, Scotty etc..etc..
Not sure about that. I roasted 4 plugs and a coil on a modern MB 1.8 turbo (271 evo) because the coils are not well-sealed. The spark plug tubes filled up with water after I rinsed the engine bay with a garden hose.
Nowadays I only wash engines that I am familiar with or around the areas that I have resealed for leaks.
We were always weary if a car for trade-in had an extremely clean engine... either had been worked on or leaks
I know water gets underhood on my cars--but they aren't an MB. I wonder if grille design matters here, where does water splash go.
Did that car have an underbelly pan? I wonder if MB and/or others do have setups where they do not expect water to get in under normal circumstances? Which would lead to, some car engines can be hosed off, some can't.
Yes, it did have an underbody pan.
The coil units on that engine do not have the usual rubber seal:
https://www.eeuroparts.com/Parts/138008/Ignition-Coil-0001502580/
The issue *may* have been exclusive to this particular MB engine model, but I am honestly not sure.
Bummer. There's always gotta be that exception to the rule it seems.
Coil on plug type ignition coils are supposed to seal the spark plug tube from water getting down into it, just like spark plug wires before also sealed the tube. I'm sure Mercedes designed the M271 coil plugs to seal out water, if they are letting water in then I'd suspect the seal is bad, not sitting right, or the coil plug isn't bolted down securely. Besides the M271 comes with a plastic engine cover over the valve cover so that diverts a lot of water if you wash the engine.
I’ve always cleaned my engine bays. Easier to identify a problem or leak before it becomes serious. Plus, I’ve heard that dust and dirt caked on the engine can cause a lack of heat removal and force the cooling system to work harder. Ford also recommends cleaning the engine in the owner’s manual. Either way, I love a clean car and engine bay. 145k on the 2015 Fusion.
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Coils were bolted down securely. There was nothing wrong with the coil.
The engine has a large plastic cover and the cover was removed to clean the area due to a major repair. I suppose MB was relying on the engine cover to prevent water from reaching the coils?
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