Post by
Pwnin O'Brien »
https://forums.nicoclub.com/pwnin-o-brien-u136941.html
Thu Jul 02, 2009 4:15 pm
I pressure wash my engine bay and undercarriage about once every two weeks. You would be surprised the kinda stuff that gets flushed out of the undercarriage, especially around the wheel wells.
I just take some degreaser and spray it on and let it sit for a little while (on both the engine bay and undercarriage, use the same stuff). I then use my 2500psi pressure washer, and wash the engine and the undercarriage. The catch with washing the engine bay. depending on the psi of your pressure washer, you want the wand to be at least 4-5 feet from the engine. This may sound useless, but the air that the pressure washer pushes is also good cleaning, because it acts almost like a air compressor. It works really really well.
Most people worry about messing up the electronics, which is almost never an issue, unless the car is 20 years old. Nissan uses really water tight seals on the engine connectors, you could probably completely submerse each connector in water and not have an issue. The only issue would be if you have rotting rubber seals, I would check that before washing, just a quick visual inspection. With the car off tho, I'm sure you won't have any issues. I would also give the car 20 minutes or so to dry off before starting it, just in case some water did get into any important areas. Also, be sure to cover the air filter with some plastic wrap or a plastic bag (if you have an aftermarket exposed filter element).
Another tip, don't even come close to the fins of the radiator, it will just bend every fin within a millisecond, not good. When washing the undercarriage, you also want to be careful not to wash off the rust resistant coating, but this usually takes a lot of pressure and a pencil thin stream.
I would recommend using a degreaser and engine shine combo for the undercarriage, my rear diff. looks amazing once I clean it, it looks like brand new.
Other than that, I would highly recommend routine engine bay/undercarriage cleaning.