[carseatsm5]

I think I can as long as I’m careful around the air intake. But can I really?

Would like to clean the engine compartment but am skeptical I won’t ruin something.

[TR930]

Not unless you want to Brick your DME.

[335i54n]

yup, all the connections are sealed. light pressure and stay away from valleys where water will collect, open air filters and go for a drive after. the newer cars are pretty covered up so light spray to dust it off and clear out the cowl of debris imo

[cooolone2]

Lol...

A disaster waiting to happen! Why would you want to use a pressure washer? You DO realize that it won't remove all dirt, let alone anything from fluids, grease or oils...

Spray bottle with some simple green and a bucket of water with a dozen cheap throw away microfibers...

If any oil on engine or firewall say, use a de-greaser!

Power Washer... Lol
Just NO!

[ttaidapos]

Wide angle from a distance is perfectly fine. Been doing it for years, new and old cars. Like others said, go for a drive after and finish off with a leaf blower and/or towels.

[carseatsm5]

Responses so far closely align with my own split mindedness

[TheMidnightNarwhal]

Yeah somewhat. I always detail my car engine bay every year and I use my pressure washer to rinse it. I will cover open air intakes and electric things that jump to my eye like alternator and the relay connection for the fan. I also like to unplug battery now just to make sure. You just don't want to keep the pressure washer in one area and you are good to go and use the widest attachment you have.

[DoubleDave]

I always advise against using a pressure washer to detail an engine. Not worth the potential headache of driving water into places where it shouldn’t go.

[MADBMWX5MC]

Good question, I have never done it, but others have...yet, I wouldn't...just me...

[tracer bullet]

Actually I think the answers sort of align - it's OK to have water on the engine. It's not OK to blast a single spot with high pressure from an inch away. If you're using a pressure washer like that you're asking for trouble. If you're using it to get the engine wet, or to rinse it, and you're doing it form like 5' away or something where it's fanned out then yeah, it should handle it.

I still would just use a normal hose. Wet things down, hit them with a spray cleaner of your choice (could have tire / rubber cleaning / protecting in it, could be degreasing, maybe a combo). Scrub a bit as needed w/ a brush, rinse, and then dry. Leaf blower is a good start, towels for the rest.

A caveat can be the age of the car - if it's an 80's collectible then it won't be quite as robust to this as something new.

Do keep water out of any open air filters, avoid blowing up an air intakes, don't soak an alternator with heavy duty cleaners (or they can remove the oil form the bearings, don't ask me how I know).

[kosd]

I cover my alternator with a bag then spray diluted meguiars all purpose cleaner all around the areas I want to clean (cold engine only) and agitate with a boars hair brush. I use a garden hose throttled to very low pressure to rinse. I usually do this once, maybe twice a year and it has worked well. I dry with a microfiber towel on the areas I can reach. In one vehicle where I had a previous oil leak, I used brake clean to clean the affected areas before doing my normal engine bay detail.

I would not use a pressure washer. In my opinion, less is more when detailing areas with the potential to damage electronics.

[grannyknot]

I've been pwr washing engines bays for years with no problem just use some common sense,
don't test how water proof the ECU box is for instance. If it's really dirty spray it down with some engine degreaser first, let it sit then pwr wash. As others have mentioned, blow it off with compressed air and take it out for an hours drive.

[Dochere2]

Originally Posted by grannyknot

I've been pwr washing engines bays for years with no problem just use some common sense...

This. I've never had an issue and I've power washed my engine bays probably 4 times a year for the last 30 or so years. In the early 2000's I had a show car that had the engine bay washed near weekly for a couple of years. Never a single problem. I do use cleaners that I know are safe for rubber, seals, etc and I typically use a 40 degree nozzle. I pre-clean areas that need it (spray, brush) before blasting out the bay. I typically leave the engine running, but I have washed with it off. I also wash the cover, if present, by hand and I never spray the areas under the cover; Again, detail by hand if needed. Watch areas that water will pool. Again, use common sense and you'll be fine.

[VegasG42]

Absolutely not worth the risk. Just use a moist towel to clean everything as good as possible

[cozye]

Water in the engine bay? Insanity. These delicate machines are not meant to get wet. There is a warning on the visor that says you should pull over in a down pour or you might get your engine wet.

(note sarcasm)..

Literally every component in that engine bay is designed to be water tight. Like a previous commenter said, use some common sense and don’t use the white nozzle on your power washer wand trying to blast off paint from 1” away. I have been using power washers from a couple feet away to clean engine bays since the 80’s (even the wand at the car wash). If you have open air intakes or an old small block chevy with a chrome Moroso air cleaner, don’t hit that with the wand.. LOL.

Don’t be a victim of the fear mongering. If water in the engine bay hurt anything there would be a pile of cars on the motorway every time a storm brewed up.

[ShocknAwe]

Brake cleaner simple green and a garden hose with a sprayer. Why over complicate things.

Pressure wash with a low pressure and wide nozzle prob fine. We drive fast in rain..

[tracer bullet]

Originally Posted by cozye

Don’t be a victim of the fear mongering. If water in the engine bay hurt anything there would be a pile of cars on the motorway every time a storm brewed up.

So, you start with a straw man, then go on to agree that you should be careful or something could happen, then finish with another straw man. You actually agree with a lot of the things people said, but also suggest to ignore them.

[TheMidnightNarwhal]

Originally Posted by tracer bullet

So, you start with a straw man, then go on to agree that you should be careful or something could happen, then finish with another straw man. You actually agree with a lot of the things people said, but also suggest to ignore them.

I mean they are right. Modern cars are waterproof underneath. It's just obviously don't spray water deep into alternator so covering it is best. Or if you have open air intake, obviously you need to cover that as well.

[Ralph III]

Hello OP,
I'm a former professional Detailer which includes working out of a Dealer only auction for 14 years. I couldn't begin to guess how many engine bays we detailed but it would be well over 60,000. We never had an issue with such. It's a matter of technique and common sense.

Consequently, I have no reservations about pressure washing an engine bay. The goal is just to quickly rinse off the de-greaser you may have sprayed on it. Also, DO NOT use a water hose because you'll be flooding the engine bay in comparison to a pressure washer. It will take a minimum amount of water for a pressure washer to accomplish what you desire. I'd never recommend the former.

God Bless,
Ralph

[carseatsm5]

Originally Posted by Ralph III

Hello OP,
I'm a former professional Detailer which includes working out of a Dealer only auction for 14 years. I couldn't begin to guess how many engine bays we detailed but it would be well over 60,000. We never had an issue with such. It's a matter of technique and common sense.

Consequently, I have no reservations about pressure washing an engine bay. The goal is just to quickly rinse off the de-greaser you may have sprayed on it. Also, DO NOT use a water hose because you'll be flooding the engine bay in comparison to a pressure washer. It will take a minimum amount of water for a pressure to accomplish what you desire, in comparison. I'd never recommend the former.

God Bless,
Ralph

Hard to argue with that experience!

[cozye]

Originally Posted by tracer bullet

So, you start with a straw man, then go on to agree that you should be careful or something could happen, then finish with another straw man. You actually agree with a lot of the things people said, but also suggest to ignore them.

You’re really fishing for that arent you? Beyond the sarcasm, I clearly stated there is no harm at all beyond spraying into an open air filter, with a joke about old air filters on hot rods. TheMidnightNarwhal got it, sorry it was over your head.

[BruinMan]

I would use a pressure washer over a garden hose. It is a must to cover the alternator with a large ziplock bag and stay away from air intakes. Obviously, spray lightly over electrical connections. This video is worth a watch.