I have access to one of these: http://brightcove.vo.llnwd.net/e1/uds/pd/1834613806001/1834613806001_4711822765001_4711805385001.mp4
Is this too powerful with which to wash my car? How does it compare pressure-wise to the local car wash?
If it looks like it’ll be too powerful, just keep it a short distance away from the car. From the video, it looks like keeping the tip 2-4 feet away would have a very low chance of causing damage, but I’m just a random internet person looking at a video. I think once you start, common sense will tell you what’s safe.
Just don’t be tempted to wash the engine with it. Far too many electronic components around there.
It’s significantly more powerful than the local car wash. At close range, it will strip the paint off of the car.
We have a less powerful electric power washer. My son bought it to clean the mud off of his dirt bikes. It’s great for cleaning cars and motorcycles. I’ve done my motorcycles and cars with it. Even though it doesn’t have quite as much power as a gasoline operated one, we still have to be careful with it.
Power washers are also great for cleaning brick, but again, don’t get too close or it will strip the mortar out from between the bricks. Good for aluminum siding as well.
The bottom line is, if you’re careful, there’s no such thing as a pressure washer that’s “too powerful”. Hold it 20 feet from the car and there’s no way it’s going to damage it. (Of course, it probably won’t clean the car very well either.) You just need to choose an appropriate nozzle and hold it an appropriate distance from the car.
One thing to keep in mind, you’re not really using it to clean the car. You’ll use it to get the car wet, maybe knock loose dirt and mud off and help clean the wheels, then you’ll wash the car and use the pressure washer to get the soap off. It’s really just a glorified water hose. You won’t use it on the car the same way they use it in the video to clean a sidewalk.
This is not really the problem you’d think it is, people wash engines all the time.
yes, do not use a pressure washer on your car.
the wands at the local quarter car wash are pressurized by air from an air compressor. they’re running maybe 90-120 psi.
pressure washers, on the other hand, use hydraulic pumps and can generate 1000-2000 psi of pressure, and can easily strip paint. and on a car will blow right through seals, gaskets, electrical connectors, and so on. if you want to wash your car in your driveway, use a garden hose, a bucket of water with (car wash) detergent, and a wash mitt.
they don’t do it with 2000 psi pressure washers.
And while many/most of them don’t have a problem, some of them create short circuits that interfere with engine operation and are very vexing to find and fix.
They do, they just don’t stick it 2 inches from everything.
It’s pretty rare though. Dealerships wash the engine on every used car they sell, then they usually spray that greasy dressing crap all over them too.
Thanks for the replies. I might just head down to the local car wash and not try to save the couple of bucks. Knowing my luck I’d do more harm than good.
I don’t believe this is true. Car wash wands are typically 1000-1200 psi.
That said, I agree with the garden hose approach. There is no reason to use a pressure washer.
mmm
I wouldn’t give up on it yet. They control for the pressure with the various wand tips they discuss in the video. In the video they show the guy washing a wood porch column. There is no way he could do that with straight 2700PSI, he’d be ripping off the paint plus the top layer of wood. I’d check into it further and see what tips they have and what they recommend those tips for. Also - some models offer a low pressure / high pressure mode.
The electric Karcher I have has various tips for different applications but you do need to use them. I learned my lesson: I was lazy and decided to power wash my wood deck and didn’t change tips. The pressure blasted the top 1/8" of wood away before I could release the trigger The good news was I started in a very inconspicuous place. My secret.
Last comment - I agree 100% with the others about buying one only to wash your car.
I’ve had various pressure washers for about 20 years. I find them super useful, I use mine all over the exterior of the house every spring: decks, interlock brick, flagstone garden paths, house siding etc. I usually use it for our cars’ wheel wells and undercarriage in the spring to get the winter salt and dirt off, but otherwise I use the garden hose. Unless you’re doing off-road racing every weekend, it would be tough to justify for a car only.
I live in California. If it was as easy as using a water hose I’d just do that. As an apt manager, there’s a loophole that I can use with the pressure washer. But again, I don’t want to do more damage than good.
all of the self-serve car washes by me are run via air compressor. 1000-1200 psi is way beyond the level where you risk high pressure injection injury, do you think car washes are going to open themselves up to that kind of liability giving the average numpty a 1200 psi pressure wand?
In my opinion, one of the major drawbacks of the gasoline-powered pressure washers that is rarely mentioned is that the pump is running continuously while the engine is running. Since the pump is cooled by the water flowing through it, when you are not spraying, you are not flowing water through the pump and it can overheat, damaging the seals. A minute or two isn’t going to do much harm, but if the engine is running, you need to be either spraying or shutting off the engine.
I prefer the electric ones. They are powerful enough to clean your driveway (although it might take a little longer), but they aren’t so powerful as to cause damage and/or injury if the operator happens to be a bit careless. They also have a pressure switch that shuts off the pump if the water flow stops. Finally, there is no carburetor to gunk-up or fowl if you happen not to use it for a year or two. Plug it in and you are ready to go.
Mine says not to go over about 6 minutes without water running through it. Otherwise you are supposed to shut it down.
Nothing’s worse than when some damn fool bird gets stuck in your carburetor. I *hate *it when that happens. 
I dunno, I’m not an expert. The folks in my cite, who are car wash owners, all appear fine with 1200 though.
mmm
Pressure washers are used for cleaning bikes during and after cyclocross races all the time, though I don’t know what sort of pressures they’re running. I think they generally use the 25° fan nozzles and stay at least a foot away. Bicycle paint is basically the same as automotive paint, and bikes have various seals and gaskets too which don’t seem to get damaged. It is important to re-lube the drivetrain and such afterwards, which wouldn’t matter for a car.
I could totally see using a pressure washer at least to clean car wheels, since brake dust and other road grime usually requires scrubbing and is more work than washing the whole rest of the car. As for the engine, aren’t those usually steam cleaned? Everything in there is already designed for a very hot environment, and steam cleans without the force of a pressure washer.