I just bought a pressure washer and i was wondering how i should clean my engine. Should i leave the engine running or leave off, and i was wondering if i could hurt any of the electrical components in the engine compartment. Thanks :D

all i know is that you have to cover the battery and the air intake inlet with water proof plastic or something, and the fuse box too i think.

you should be ok either way. just make sure all the little fuse box's are shut tight. Also you don't want to pray directly into the intake. I would not do it with the motor hot. Also you need to find out how powerful that sprayer is before you do the motor. I have seen some people wash holes in the hoses with them!!!

As for engine cleaners i usually just spray some 409 or simple green on i

Is your engine compartment really, really gunked up? If not, you shouldn't even need the pressure washer. I wash mine every couple of months by spraying simple green on it, letting it soak, maybe scrubbing a few areas and then hosing it off (I don't use a nozzel on the hose - just let the water run out).

I don't feel very comfortable spraying high pressure water around all that wiring, relays, etc.

Power washing engine is just fine. Follow these directions:

1. COLD motor
2. Simple Green, 1:1 dilution rate. Apply with spray bottle
3. Sit one to three minutes
4. agitate areas in need
5. spray off, don't pray into intake, no need to wrap anything
6. towel dry all easy to reach areas (don't go crazy)
7. start engine (let it dry itself with heat)


and, if absolutely necessary, apply some sort of plastic dressing when the motor is cool again so everything is bright and shiny under the hood (but this attracts dust)

I would just use a regular hose first with a garden sprayer. The simple green should remove almost anything. If there is some particularly bad area, maybe then use the pressure washer.

Water and electrical (sensors, connectors) etc don't mix. Pressure may force the water further into such places. If you exercise enough caution and if you really have a need .... but NOT when the engine is hot/warm (high or low pressure).

I once ruined the sound deadener (under side of the hood) by garden hose with the nozzle set at sharp stream.

Salim