FWIW I've never covered anything... Spray it down with degreaser, let soak, then rinse.
Best to be done on a cool/cold engine, and rinsed without a nozzel, just bulk water from a hose.
That said I've never had problems using a power washer.
I've never had water get down my air intake, though I've never intentionally sprayed water at high blast into the air filter box like an idiot... or tried starting the car while the air intake is soaking wet.
Cars are designed for thier engines to be washed, the important stuff is sealed except for the air intake if your worried.
If you spray water IN your intake you will water lock and destroy your engine when you start it, if your doing that... YOUR DOIN IT WRONG
Your milage may vary
Best to be done on a cool/cold engine, and rinsed without a nozzel, just bulk water from a hose.
That said I've never had problems using a power washer.
I've never had water get down my air intake, though I've never intentionally sprayed water at high blast into the air filter box like an idiot... or tried starting the car while the air intake is soaking wet.
Cars are designed for thier engines to be washed, the important stuff is sealed except for the air intake if your worried.
If you spray water IN your intake you will water lock and destroy your engine when you start it, if your doing that... YOUR DOIN IT WRONG
Your milage may vary