Power washing undercarriage- what to look for

[billschroeder5842]

I have a power washer (1600 PSI) and I'm thinking of washing the undercarriage and wheel wells on my '91 ZR1. I'm also thinking of doing some engine/cradle washing but only below the heads-- nothing on top that can get through the plenum.

I'm just looking for a general clean up of the suspension and undercariage- I'm aware to stay clean of electrical connections.

Is there any concern about a general clean up? Is there any areas or components that are particularly fragile?

I posted this also on CF so we see what they say.

Thanks!

[WARP TEN]

I would definitely suggest using a very low pressure on your pressure washer. A number of years ago I had a friend who got a pressure washer to clean his boat decks. When he first tried it it was set at 3,000 psi and he promptly blew a hole right through the fiberglass foredeck. But more practically, you might want to spray degreaser on the greasier spots first to loosen things up. Also, while more expensive and normally done by professionals, you might consider dry ice blasting. That seems to work really well without the mess of a lot of water in your driveway or garage. But it is a bit pricey. Good luck!--Bob

[silver86]

I would 2nd the dry ice blasting. It is pricey, but does not blast away anything that shouldn't be.

[billschroeder5842]

I would 2nd the dry ice blasting. It is pricey, but does not blast away anything that shouldn't be.

I'm interested, but don't really have an idea of how it works. I always heard that one must stay away from the top of the engine (plennum area) as liquids under the plennum can really mess things up.

[conesare2seconds]

I?d avoid using the pressure washer altogether. If you do, give special care to wiring looms. The plastic is brittle from age by now. If you do the wheel wells you will encounter the wiring for the ABS/wheel speed sensor. I?ve seen that wiring losing its insulation, flaking off, probably contributed to by brake heat.

[AirbusDriver]

I've heard, but no idea if it's valid, dry ice can/will remove factory applied undercoating...if that's important. NCRS types would be concerned, for sure.