# No power washing the engine...



## gman19 (Apr 5, 2011)

I think you should be able to use a power washer in the engine bay.....The plastic boxes stamped "No Power Washing" are the PDC boxes and I'm pretty sure you do NOT want to direct a stream from the power washer directly onto those...thus the warning.

I keep clean under the hood as you suggested by spraying and wiping things off. I do this regularly enough, that I have not found the need for pressure washing under there yet.


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## newcruzer17 (Feb 8, 2012)

I may be mistaken, (I'm 1000 miles from my car at the moment so I can't look) but I believe that is an area where you have a fusebox. I believe you can wash the engine compartment as long as you don't directly spray the fusebox. Someone correct me if I am wrong.


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## GoldenCruze (Dec 18, 2011)

You don't want to pressure wash those individual components. They are weather sealed however, (come on, it's the engine bay!) so a light rain over them shouldn't hurt. If you want to see what's under those covers, open the up. The big one is a fuse box, and the other is the multiple hot leads hooked up to the battery.


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## Beaker (Mar 21, 2012)

PLEASE FOR THE LOVE OF GOD DON'T WASH YOUR **** ENGINE!

The reason you don't wash or power wash the car is not only because of the fuse box and the battery but also the alternator. You will short things out if the alternator gets too much water on it. If you want to clean your engine bay, do it the non-retarded way and use your arms and some cloths. In the old days sure you could cover up the battery and alternator and rinse things off with a hose. But with the amount of electronics in a car today, I would err not only the side of personal safety (from electric shock) but that of your vehicles health as well.


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## mcg75 (Mar 5, 2012)

Pressure washing is a no-no for sure. 

Engine degreaser followed by a garden hose wash down will be fine. Won't put any more pressure than driving in the rain.


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## parish8 (Mar 11, 2012)

i dont know about power washing but i have been washing under the hoods of my cars for 25 years with no issues. i spray things down with some engine cleaner and then rinse with low pressure water. then start it and let it idle for 1/2hour or so to really dry things out. it looks like new under there without that super shiny look that the dealers do on used cars.


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## XtremeRevolution (Jan 19, 2012)

Never had an issue power washing a car. Just let it sit for a bit so all of the water dries and you won't have a problem. 

I have never once heard of an alternator shorting out from the car getting power washed.


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## Beaker (Mar 21, 2012)

Power washing the car no (of course that's bad for the paint). Power washing the engine I wouldn't think of doing. If you're going to rinse off the engine with a hose, just be sure to cover electrical components with plastic bags. Me personally I'd still never do that. Maybe the surrounding sidewalls. But not the actual engine. When I sold my Cobalt after 3 years nad 50,000 miles, you could eat off the top of the motor and I didn't need a hose to get it clean.


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## XtremeRevolution (Jan 19, 2012)

Beaker said:


> Power washing the car no (of course that's bad for the paint). Power washing the engine I wouldn't think of doing. If you're going to rinse off the engine with a hose, just be sure to cover electrical components with plastic bags. Me personally I'd still never do that. Maybe the surrounding sidewalls. But not the actual engine. When I sold my Cobalt after 3 years nad 50,000 miles, you could eat off the top of the motor and I didn't need a hose to get it clean.


Can't say I've ever had an issue power washing my car with a hose. In fact, the only car that's ever had an issue getting power washed is my sister in law's 96 Regal, where there's rust under the paint so if you spray the rusted areas, it starts peeling up the paint. 

You're telling me that your car's paint can withstand flies, and bees at 70mph but it can't withstand water from a power washer? Power washing the exterior of your car is 100% safe. In fact, not only is it safe, but it's safer than doing it by hand. Doing it by hand, you're much more likely to rub dirt in swirls on the car's finish, while the power washer gets most of that dirt off without creating those swirls, leaving your car's clear coat swirl and scratch-free.

This is a home gas power washer we're talking about here, not an industrial cutting and engraving tool. I've been power washing my cars for just over 2 years now (couldn't afford one before that) and it's by far the easiest and quickest way to get a car wash. 

What do you think the differences is between the pressure coming out of a power washer and the pressure coming out of a new touchless car wash? Even the touch car washes with those rollers that flap across your car have a much higher likelihood to damage your paint job. Most power washers, especially ones made specifically for cars, run at 1800PSI. 

My gas power washer is by far the absolute best cleaning tool I've ever purchased for my car. I only really have to wash it with soap and my hands every 4-6 weeks, which is a long time to go when you live on a 500 foot gravel driveway and drive 300 miles a week in the Chicagoland area.

Obviously, I'm not going to spray my car from an inch away with the finest tip I can find for my power washer, but within normal use, power washers are 100% safe for your car's exterior.


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## Beaker (Mar 21, 2012)

I don't use car washes either. You're going to wear off the wax far quicker with a power washer at those pressures than just a bucket and a hose.

Ultimately, if you're comfortable with it, more power to you. I prefer the old fashioned way and have never had an issue with swirls from washing with a bucket and a microfiber sponge.


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## Mick (Dec 31, 2011)

Guys just ask your dealer to clean your engine on you're next service. 
I always took my Lexus to a Chevy dealer because oil changes were cheaper and they would steam clean my engine for free.


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## XtremeRevolution (Jan 19, 2012)

Beaker said:


> I don't use car washes either. You're going to wear off the wax far quicker with a power washer at those pressures than just a bucket and a hose.
> 
> Ultimately, if you're comfortable with it, more power to you. I prefer the old fashioned way and have never had an issue with swirls from washing with a bucket and a microfiber sponge.


That's the pressure at the nozzle, not the pressure 1 foot away where I usually wash. 

Ask-A-Pro: Pressure Washers – Detailed Image

Power washers do not wear off was far quicker than doing it by hand.


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## SlvrECObullet (Feb 21, 2012)

this is some info I could learn from I have never really washed an engine alway been afraid of all the electrical stuff especially with newer cars, what would be some tips on washing my engine. considering I wont be getting much service done at the dealer I probably wont be having them clean the engine... who knows if me dealer would even do it haha...

Sent from my SCH-I500 using AutoGuide.com App


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## nobog (Oct 25, 2011)

I would NEVER power wash or steam clean the engine not- at least not anything with more than a coil and an old-fashioned distributor. Even then I would cover those things. If I absolutely had to clean under the hood, use something like S100 and a garden hose, then start and run the engine immediatly after cleaning.

Jim


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## CHUV (Jun 25, 2011)

What about using something like Simple Green on the engine? Then just hosing it off gently?


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## parish8 (Mar 11, 2012)

CHUV said:


> What about using something like Simple Green on the engine? Then just hosing it off gently?


simple green is great for stuff like that. spray it on. let it sit for a few. rinse it off. i think the spray on engine degreaser is a little stronger if your cleaning an engine that is really nasty.


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## gman19 (Apr 5, 2011)

parish8 said:


> simple green is great for stuff like that. spray it on. let it sit for a few. rinse it off. i think the spray on engine degreaser is a little stronger if your cleaning an engine that is really nasty.


This ^^ is exactly how a buddy of mine keeps his LS1 Camaro engine spotless. He sprays Simple Green onto a SLIGHTLY warm engine, lets it sit for a few minutes, then gently hoses it off. Once done, he'll crank and idle for a few minutes to allow for some drying. Done deal and the engine still looks showroom clean.


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## NickD (Dec 10, 2011)

Is safe to remove the air cleaner, less filter and clean that up nice in your laundry tub using soap and water.

Major concern with electronics and wiring are all these nanoampere signals floating around where moisture can short them out. With insulation displacement connectors on bare copper wire, and moisture, those would turn green, copper oxide, that is an excellent insulator. Other concerns are the idiots that designed your logic, we always dipped our electronics in a salt water solution powered up to test our short circuit I/O protection circuits. Of course the circuit would die, but rinse it off in fresh water, hang it up on the line to dry. They all had to be fully operational again.

But without that short circuit protection, these way overpriced electronics could be permanently internally shorted out. And you don't know if it was protected or not, if not, you found out way too late. Just clean at most with a slightly damp rag to get most of the dust off. We use to use the absolute minimum of plated stranded 16AWG wire, not for the current carrying capacity, but because it was robust. Add this practice to your history books. Find lots of bare copper 28AWG wire in these newer vehicles.


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## gman19 (Apr 5, 2011)

NickD said:


> Major concern with electronics and wiring are all these nanoampere signals floating around where moisture can short them out.


I hadn't even considered this...but yes, there are a lot of parasitic currents running around in our vehicles even whilst sitting parked!


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## XtremeRevolution (Jan 19, 2012)

I think we'd have a much bigger problem on our hands every time it rained and mist got into our engine bay if that was the case.


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## cruze2011white (Feb 2, 2011)

All this symbol is for is saying don't power wash the fuse box area. because if you do you could force water in to the circuits. These are water resistant not water proof. there just like your windows they might be closed and sealed but at the right angle water can get in. 

Anyone who thinks its not safe to wash a engine with a regular hose is mis-informed. What do think happens when you drive in the rain? Your engine gets completely wet, doesn't hurt a thing unless you have a short or something isn't tight. I've been washing my engines with the garden hose for years and never have issues. it also helps with all the plastic and rubber hoses as dirt and oil debris causes these to deteriorate much faster if they aren't kept clean. Also nice to work on clean engine instead of dirty one.


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## NickD (Dec 10, 2011)

How many vehicles have you seen with weather stripping under the front hood? Cruze 1.4 L has one. TB is motor controlled, don't want to get that wet, MAP sensor is certainly not a water proof connector as is the electronic thermostat, nor are the DIS connectors for the ignition. Sure wouldn't want to get water in that waste gate valve either and more electrical down there. Electric power steering and lamp circuits, referring to both short and long term problems.

I also used to use my pressure washer on engines, but not anymore.


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## XtremeRevolution (Jan 19, 2012)

NickD said:


> How many vehicles have you seen with weather stripping under the front hood? Cruze 1.4 L has one. TB is motor controlled, don't want to get that wet, MAP sensor is certainly not a water proof connector as is the electronic thermostat, nor are the DIS connectors for the ignition. Sure wouldn't want to get water in that waste gate valve either and more electrical down there. Electric power steering and lamp circuits, referring to both short and long term problems.
> 
> I also used to use my pressure washer on engines, but not anymore.


Nick, everything is water and weather proof on our engines, and I do mean everything. The TB is indeed motor controlled, but it is sealed and the connectors also have a gasket. If you remove one, you'll see what I mean. The electronic thermostat is also internal to the engine, and that is sealed as well (with the electrical harness having the same weather seal gasket). All ignition components are sealed, and the electric power steering is sealed as well. I'll bet the electric power steering is sealed better than the rest of the components since it is very close to the ground and will certainly get soaked. 

The reason why most of these are sealed is because you will inevitably get water in there, and GM knows that someone will inevitably take a pressure washer to the engine bay. The other reason is because of corrosion. We know how badly cars rust around here (you're not too far from me), and exposed electrical connections will corrode in no time and cause greater issues than I care to mention. My 95 Regal is sitting for that very reason; electrical gremlins I don't have the time to trace. That engine, however, has never been pressure washed. 

Now, I haven't washed my engine bay yet because I haven't had time or I simply forget, but if I took a picture of my engine bay, you'd see all of the water spots from when there was salt on the road that got into the engine bay. If anything, it is in my best interest to wash that salt off as soon as possible. 

A pressure washer may not be necessary for all but the most filthy engines, but that certainly doesn't mean that washing one's engine and engine bay is a bad idea.


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## Patman (May 7, 2011)

Is there really that much grease and grime under the hood to warrant power washing? Remember that is what the panel under the car is supposed to prevent. Wiping down or rinsing off OK but power washing come on. The last car I power washed the engine was a 73 Chevelle. with leaky valve covers. IMO.


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## XtremeRevolution (Jan 19, 2012)

Patman said:


> Is there really that much grease and grime under the hood to warrant power washing? Remember that is what the panel under the car is supposed to prevent. Wiping down or rinsing off OK but power washing come on. The last car I power washed the engine was a 73 Chevelle. with leaky valve covers. IMO.


Nothing right now that merits power washing, and probably will never if you keep up with the regular light cleanings and rinsing, but wait 5-10 years and then look at someone's Cruze engine bay who doesn't even know how to pop the hood and you'll think differently.


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## NickD (Dec 10, 2011)

Will take the safe rather than sorry position on this issue. With older cars, still can drive to the airport and borrow their steam cleaner for engines loaded with fluid leaks. With the Cavalier with just about 100K miles on it, engine compartment is still fairly clean, no fluid leaks. Hope the Cruze is just as good.

I do forward flush the radiator with low pressure hose after removing the radiator shroud first, if I can without draining the cooling system. Sure get a lot of insects in those fins that both affects cooling and AC operation. That problem has been with us forever, still gives you the idea cars were made for showrooms and maybe should stay there.

On vehicles out of warranty, remove the radiator cover and install an aluminum screen angled forward. Insects hit that and drop off, may find a few, a light brushing gets rid of that. But not a recommended practice, guess they want you to have overheating and AC problems. Just block the insect flow, plenty or air space around the engine.

Can spend hours cleaning your radiator and condenser fins, and one early morning drive through the swamps on Hy 173 will load it up with bugs again. Endless. 

Had to take a look at my cabin filter. Only tools I needed was my fingernails. A window like shade cord on the right side and two snap in limiters on each side. Then the entire glove compartment door can be removed. Find a black door with three tabs on it, left, right, and mid top, unsnap those and the filter can be pulled out. Found one little gnat in mine, rest was like new. Took that gnat and buried him in my back yard after saying a short prayer, none of his peers showed up. 

But was happy he was in the filter and not stuck in the evaporator fins.


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## JeffBazell (Jan 24, 2012)

I just power washed my 2012 Eco. No problems, but I did avoid that particular area with the "No Power Wash" symbol, just to be safe. Car started right up, but you may notice the outside air temp reading stays stuck on a cold read until it dries.


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## gman19 (Apr 5, 2011)

XtremeRevolution said:


> ...everything is water and weather proof on our engines, and I do mean everything. The TB is indeed motor controlled, but it is sealed and the connectors also have a gasket. If you remove one, you'll see what I mean. The electronic thermostat is also internal to the engine, and that is sealed as well (with the electrical harness having the same weather seal gasket). All ignition components are sealed, and the electric power steering is sealed as well. I'll bet the electric power steering is sealed better than the rest of the components since it is very close to the ground and will certainly get soaked.


Here at the lab, we're testing complete function modules right now. I do a lot for Chevy trucks, and have done several for the Volt. Sometimes they do fail, but that's the purpose of the lab...then it's back to engineering or quality control.

And yes, we do have a 5000psi heated pressure washer we use on PDC type enclosures...they typically fail when washed from UNDERNEATH or at the odd angle...sprayed directly on top they typically survive.


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## spacedout (Dec 7, 2010)

I have never found any reason to wash under the hood of any car. If its dirty I may wipe things down but only if I am doing maintenance & need to to keep my hands cleaner. besides electrical issues, I wonder what issues might happen when someone sprays down a hot turbo with cold water?


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## XtremeRevolution (Jan 19, 2012)

spacedout said:


> I have never found any reason to wash under the hood of any car. If its dirty I may wipe things down but only if I am doing maintenance & need to to keep my hands cleaner. besides electrical issues, I wonder what issues might happen when someone sprays down a hot turbo with cold water?


The water turns to steam? 

One advantage to using a power washer over a hose is that it provides a more powerful stream of water, but uses less water than you'd use with a hose.


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## thevoid (Aug 1, 2011)

No, he actually has a point there. The thermal shock would be similar to pouring water in a heated cast iron skillet. The skillet can crack or even shatter from the rapid cooling. You dont want to shatter the turbine housing, do you?


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## spacedout (Dec 7, 2010)

thevoid said:


> No, he actually has a point there. The thermal shock would be similar to pouring water in a heated cast iron skillet. The skillet can crack or even shatter from the rapid cooling. You dont want to shatter the turbine housing, do you?


Exactly! glad to see someone has some common sense. You might get away with spraying it a few times but who's to say you didn't create hairline fractures that will lower the life of the turbo? I stick by my previous statement, there is no reason to wash under the hood of a car, especially one that's so new.

I was always told if you were ever going to wash the engine compartment do it when the engine is cold, I had a friend that washed his warm/hot engine & cracked his header!


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## gman19 (Apr 5, 2011)

spacedout said:


> Exactly! glad to see someone has some common sense. You might get away with spraying it a few times but who's to say you didn't create hairline fractures that will lower the life of the turbo?


Common sense would dictate that one would never hose down or otherwise wash down an engine bay when it is any more than "lukewarm".....but I get your point....common sense is not so prevalent any more.


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## Beaker (Mar 21, 2012)

The only time this should really be an issue is on automatic car washes(most people don't wash their car themselves directly after driving it). If you're driving home with a lot of stop and go and stop for a car wash, your turbo will likely be hot. A lot of car washes spray under the car to clean off the undercarriage. Bodes poorly for a hot turbo over time.

Another reason not to use automatic car washes though.


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## XtremeRevolution (Jan 19, 2012)

thevoid said:


> No, he actually has a point there. The thermal shock would be similar to pouring water in a heated cast iron skillet. The skillet can crack or even shatter from the rapid cooling. You dont want to shatter the turbine housing, do you?





spacedout said:


> Exactly! glad to see someone has some common sense. You might get away with spraying it a few times but who's to say you didn't create hairline fractures that will lower the life of the turbo? I stick by my previous statement, there is no reason to wash under the hood of a car, especially one that's so new.
> 
> I was always told if you were ever going to wash the engine compartment do it when the engine is cold, I had a friend that washed his warm/hot engine & cracked his header!


Here's the problem with that: the comparison isn't a valid one. The concept is correct, but the application is not. That's the same as saying you shouldn't you shouldn't swim in a swimming pool because water causes people to drown. 

When you're pouring water into an iron skillet, you're *very *rapidly changing the temperature because of the sheer amount of water. The amount of heat inside the skillet will not overcome the amount of water you've now put inside it and will not heat up the water enough to slow down that cooling rate. Try instead trickling water into a hot iron skillet. Put maybe half a pint in there even instantly. What happens? Lots of steam and the skillet will remain hot. The water evaporates and the skillet cools down slowly. 

Now, not only do you have a heat shield on top of the turbo and exhaust components that prevents you from pouring a bucket of water directly onto them, but you also aren't (I hope) using a bucket. In order to induce that kind of thermal shock, you'd have to submerge the turbo in water. Spraying down the engine with a hose won't cause that kind of an issue, and using a power washer will cause even less of an issue because you're using high pressure instead of high volume to get rid of dirt or remaining soap suds from whatever cleaner you sprayed on there.

Try it for yourself. Get some spray bottles and a bunch of your buddies, take off the heat shield, drive the car for 15 minutes, then park it and have everyone spray the turbo. Not only will it look absolutely hilarious, but you'll also discover that in order to induce thermal shock, you need a whole lot of water.


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## GoldenCruze (Dec 18, 2011)

Beaker said:


> The only time this should really be an issue is on automatic car washes(most people don't wash their car themselves directly after driving it). If you're driving home with a lot of stop and go and stop for a car wash, your turbo will likely be hot. A lot of car washes spray under the car to clean off the undercarriage. Bodes poorly for a hot turbo over time.
> 
> Another reason not to use automatic car washes though.


I just returned from taking my Cruze through a car wash at my dealer. It's free, so I make use of it. There's no issue with water on the hot parts for a couple of reasons. One is that the engine is still running as the car goes through. Keeps things hot. And if there is an underbody spray, then there is that shield under the engine just for the purpose of preventing water from spraying up there. Rain doesn't cause a problem, so neither should a car wash.


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