undercarriag care

I notice you have had no answers I'll be watching to see what people say.
My car has sucked up dirt and mud after this winter and was wondering the same question I would like to power wash the underneath also .Hope someone answers

 

Why bother ... who sees it. It won't hurt to wash it, but just driving through a couple of puddles will accomplish the same thing.

 

This is reasonable especially for cars driven in areas where salt is applied on winter roads. It would be good to spray out the fender liners to remove accumulated dirt, as well as the suspension etc.

I suggest that you avoid washing the engine compartment due to the many electrical connectors that have the potential to become intermittent if water moisture enters. Water can easily enter the four spark plug wells at the top of the engine valve cover since the rubber spark igniter seals are not perfect.

 

I'm not sure about pressure washing but I regularly spray off the underside of my car as well as the wheel wells. I spray it down prior to washing the rest of the car so any mud has time to soften then spray it off again near the end of the wash. I wouldn't eat off it but it stays pretty clean.

 

The rear wheel wells are the worst. It really helps if on a flat surface you jack up the rear end, support with jackstands, and remove the rear wheels. Make sure the front wheels are blocked

You can then use your pressure washer or garden hose to spray out the wheel well. In particular, dirt/salt loves to build up at the front of the rear wheel well, there is a flat area there. The lip of the wheel well holds a lot of crud too

There is a recess at the rear of the rear wheel well that is only easy to get to if the rear wheels are off. Once you get the wheels off, easy enough to hose off the crud

As Patrick suggested, do *not* touch the engine bay. One of our forum members, Frank Hudon, does like to hose off the engine area. He then removes each coil igniter and uses compressed air to thoroughly blow out each tube.

The only place I have seen crud build up in the front end is the strut, there is a flat area near the top. If you're careful you can hose that off without getting water on the motor

The plastic fairings under the car love to hold dirt. It takes patience and 2-3 beers to thoroughly clean off underneath the car