Washing the car engine

imoldernu

Gone but not forgotten
Joined
Jul 18, 2012
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Back in 1958 I was working for Sears as a trainee. Part of the training was to spend time in every department. My week in auto repair taught me about clean engines. Part of what we did prior to doing engine work, was to steam clean the engine. Sometimes caused a hard start for a few minutes, but made the mechanic's work cleaner and easier.
Ever since, I've washed my car engines at least once a year... spray with a grease/oil remover and then hose off the crud. Baking soda on the battery terminals.
Many Utube instructions about covering wiring, but I've never done that, and never had trouble starting.
I also used to do this kind of cleaning under the car, but at this age, afraid I might get stuck.

Apparently not everyone does this. Whenever I have my 96 SLS and 98 Town car serviced, I get comments about how clean the engine is.

Many spray-on products for cleaning in the auto stores... I use whatever I have available, and everything seem tow work fine.

After cleaning, a quick spray with a vinyl/rubber protectant.

Is this standard procedure? Do most owners wash their car engines. :confused:
 
Mine are cleaned by me whenever I have to work on one.

I recently restored a 2003 VW Jetta TDI with 300,000 miles on the ODO and the engine was a mess when I got it. I had to use a power washer on it to get it clean enough for me to see where the oil leaks were originating.

I use the store brand engine degreasers and sometimes Simple Green (but not on aluminum parts).
 
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I used to do it. Even did it at a car wash sometimes. Never had trouble starting, although like you said, sometimes it would run slightly rough for a few minutes.

It's probably a great idea.
 
I've never cleaned my engine and never heard of anyone else doing it until now. I'll clean the crud off the battery from time to time but that's it. I don't think there's any mechanical advantage to doing it but if it makes you feel better about how the engine looks then go ahead and keep doing it.
 
I used to do it. Even did it at a car wash sometimes. Never had trouble starting, although like you said, sometimes it would run slightly rough for a few minutes.

It's probably a great idea.

+1 I would usually keep it running while I pressured washed it.
 
I've never cleaned my engine and never heard of anyone else doing it until now. I'll clean the crud off the battery from time to time but that's it. I don't think there's any mechanical advantage to doing it but if it makes you feel better about how the engine looks then go ahead and keep doing it.

The advantage to cleaning is is to identify areas of concern, if you are equipped to do that. ;) And, if you happen to be the one who works on it, you won't get as greasy!:dance:
 
I don't do it, though if I were doing real work on my engine I would definitely prefer to have it clean. It also makes it easier to spot (and track) small fluid leaks.

I'd be worried about shorting out/mucking up some of the computers and sensors under the hood of a modern car. In the old days, the worst that could happen is you could force water into the distributor and cause some temporary problem with the points. Nowadays, destroying a bit of electronics could be very costly, and sometimes troubleshooting a problem like that can also be expensive.

It's also not the most environmentally friendly thing to do. All that oil, lube, and solvent has to go somewhere, and it only takes a tiny bit to foul a >lot< of surface/groundwater (where runoff from driveways ends up). Most self-serve carwashes where I live will not permit people to clean engines there.

So, while I thought I was being lazy, I was really being environmentally conscious.
 
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To be honest, I probably keep my engines and the engine compartments "almost" as clean as I keep the cars interior and exterior car body. And I like clean cars.
 
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I only once cleaned the engine, I forget why, and it didn't seem to make any difference. Like others, I was concerned about getting water into spots where it would cause electrical problems. I've heard that it can help the engine run a bit cooler but I'd think the oil/grease/dirt coating would have to be pretty thick to make much of a difference.
 
On my classic cars, yes I clean them regularly. On daily driver type, depends. If I have a big repair, I will clean it so my work is less messy. Since I change my own oil and do most all of the other maintenance, it is in my interest to keep it clean and have good idea where leaks may be developing.

Newer cars are much better at staying clean than older engines. The seals used now are much better than the older seals. Plus add in the emissions controls where the engine just runs cleaner to start with. Result is newer engines just do not get as dirty and greasy as the older ones. Older by my definition is 40+ years.

For real heavy degreasing, the cheap dollar store oven cleaner works great. For normal cleaning, the spray-on engine cleaners works good, I prefer Gunk Engine Brite regular formula. Just avoid spraying water directly on electrical connectors.
 
To be honest, I probably keep my engines and the engine compartments "almost" as clean as I keep the cars interior and exterior car body. And I like clean cars.

Me too. And I feel it would allow me to spot impending trouble (such as a developing leak) sooner than if crud was in the way.

Here in the desert the dust buildup is incredible, although it allows you to spot the pack rat footprints rather easily.

_B
 
I spray a degreaser, let it sit for about 15 minutes and power wash the engine once a year. I do this on all our "daily drivers". I do this as I work on my own cars and it's just easier and more inviting when repairs or maintenance are required. It also helps be identify if there are any leaks.

I believe the main reason I do this is because I do my own maintenance and repairs. My wife brought the car in for a repair once when I was out of town several years ago and the mechanic commented on how he though someone took really good car of the car based on how clean the engine was for a 14 year old car.
 
I've had several garage queens, wiped engines clean by hand, there was never any need to hose these engines down since they were never allowed to get dirty in the first place. On daily drivers, nothing really in the way of engine cleaning.
 
All my cars have plastic covers covering the engines that can be removed and cleaned.

That's as close to clean as my engines are going to get.
 
Did it a couple of times in the 1970s, why? Don't remember. Never did it again and would not think of doing it today unless I had a proper facility to deal with the greasy run-off. I would not consider it environmentally friendly.
 
I keep them pretty clean but I quit using degreaser years ago. I usually use simple green and low pressure water from the garden hose with the engine running or start it immediately and let it run until dry. Once per year. If when I do go to a shop for work they always comment. I do a fair bit of work on my cars and I hate working on a dirty machine.


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I better not mention this to my husband otherwise it will be his new obsession.
 
After each oil change, I cover the alternator with plastic, use a quart squirt bottle with a 50/50 solution of Purple Power and H2O to completely soak the engine, use a water hose with a jet nozzle to completely rinse , dry with a leaf blower, then shine the plastic and hoses with a vinyl/rubber protectant. Still look brand new no matter how many miles. Never have hard starts after cleaning.
 
To each his / her own - its your car - maintain as you like.

I do nearly the maintenance on all five of our families vehicles because it is an enjoyable hobby for me and my son. Goal is to change out components like camshaft sensors, valve breather sealers, vacuum hoses and valve cover gaskets at 100,000 miles before they start leaking due to age. Gotta admit, I don't wash any of the engines with a sprayer. Spot cleaning only by hand.

As previously mentioned, modern engines have a lot more electronics, voltage sensitive computer processors and a lot more electrical connectors in the engine compartment than in years gone by - which increases the possibility of an electrical short during spray washing. Keeping the car engine running while spray washing or shortly after washing dramatically increases the potential for shorting out a low voltage microprocessor. Additionally, more and more engines parts (other than the blocks which are usually aluminum) are now being built with magnesium instead of aluminum. Magnesium has a greater corrosion potential than aluminum, and will corrode with some degreasers applied. In a few cases, the magnesium will corrode from a degreaser to the point of component failure (such as deforming the channels of breather covers). Some engines are built with spark plug wells that face upwards, and will collect water and track over the wash down of dirt to give cylinder misfires.

Of course, if an engine has to be washed to find and fix the source of a leak, hand wiping is safe. If a spray wash is done, the alternator must be covered at minimum. Let things dry out thoroughly before putting the key in the ignition to minimize the change of tracking over stray voltages.
 
Dayum. You mean "engine shampoos" are legitimate? :LOL:

My all-time favorite Car Talk episode was a guy who called in after taking his car to one of those "Quick Lube" places where they charge some insanely low price for the oil change and then find a lot of expensive things that need to be done. He said they sold him an "engine shampoo" and wanted to know if his friends who told him he'd been ripped off were right.

After they picked themselves up off the floor where they'd fallen down laughing, they asked if he'd gotten the conditioner, too. Bottom line: not necessary.

I've never washed an engine and don't believe I've ever had a mechanic do it, either. Now that I think of it, though, when I looked under the hood of the first car I ever bought (a 1973 Hornet, in 1975) at the dealership, it appeared nice and clean.
 
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