Should I clean my undercarriage or no point

[TheMidnightNarwhal]

Hello folks, a bit long thread to give you guys/gals perspective.

I have a 2011 BMW that I drive even in winters here in Canada. I'm not that worried about rust since my car is mainly made of aluminum, plastic and galvanized steel. Now some nuts and bolts thought that's another story. But. some of my friends say I'm crazy and I do think some stuff can still rust.

That said, in the winter I usually rinse the car at a car wash manual with just water every 2 weeks-ish. When the temps raise slightly above 2c I usually do a ONR wash on the outside and re-apply some bead maker.

This leave me with under the car. My car has belly pan though up front. I thought to do, when spring arrives and temps stay above zero (meaning pressure washer can be used and outside water works) to lift the car all up, remove belly pan, spray degreaser under the car and use a pressure washer broom to rinse that off. Plus usually rust happens when above 0 and salty water arrives.

My question is, is doing all of this completely useless or will it actually do something? I assume I would have to do this weekly or every 2 weeks or else there is no point?

[acuRAS82]

My opinion: no point until spring. Even doing it every week, you never know. I believe corrosion happens fastest during changes from cold to warm and back, which is probably being reintroduced by the water after cleaning.

Opinion only.

[Bill D]

Depends how obsessive you are. When I lived up north I used to clean my undercarriage year round. Even went through torture doing it in the winter. Now that I live in Florida, I just throw the car on my lift and inspect the undercarriage seasonally.

[Mike@DedicatedPerfection]

I do the bottom of my BMW's maybe 2-3 times throughout the winter season. Just make sure the temps will stay above freezing for a few days after doing the bottom to allow for it to dry out a bit.

I put this together a few years ago using the Karcher Chassis cleaner attachment for my Karcher pressure washer.
Product Review: Kärcher Underbody Chassis Cleaner (https://www.autogeekonline.net/forum/product-reviews/98800-product-review-k-rcher-underbody-chassis-cleaner.html)

[FUNX650]

I have a 2011 BMW that I drive even
in winters here in Canada.

I'm not that worried about rust since my
car is mainly made of aluminum, plastic
and galvanized steel. Now some nuts and
bolts thought that's another story.

But. some of my friends say I'm crazy
and I do think some stuff can still rust.

That said, in the winter I usually rinse the
car at a car wash manual with just water
every 2 weeks-ish. When the temps raise
slightly above 2c I usually do a ONR wash
on the outside and re-apply some bead maker.

This leave me with under the car.
My car has belly pan though up front.

I thought to do, when spring arrives and
temps stay above zero (meaning pressure
washer can be used and outside water works)
to lift the car all up, remove belly pan, spray
degreaser under the car and use a pressure
washer broom to rinse that off.

Plus usually rust happens when above 0
and salty water arrives.

My question is, is doing all of this completely
useless or will it actually do something?

I assume I would have to do this weekly or
every 2 weeks or else there is no point?

The materials you mention above may not be
susceptible to rusting, per se; but another form
of corrosion (oxidation) could/can be occurring.

•Therefore it’s advisable to rinse off your car’s
undercarriage, every now and then, during the
winter season when road salts are being used.

I, for one, won’t wait ‘til Spring to arrive
to ”de-salt” our vehicles’ undercarriages.



Bob

[MarkD51]

Some say it holds no advantage. Me, I've always tried keeping up with underside maintainence and cleanings as the winter wore on.

Like is mentioned, and when permissible, a run over to the coin op wash, clear water spray best I could, wheel wells, underside, get all that nasty hanging ice, and road salt films and crud off.

[Farmallluvr]

I say power wash the underside as much as you can and let it dry if you have a heated garage.,,the sodium chloride in road salt actually accelerates the corrosion process,,,I like to use cavity waxes where ever I can because some places you just can't rinse.,,,get ahead of it and stay ahead of it.



Winter Weather Myths: Does Road Salt Actually Cause Rust on Cars? - The News Wheel (https://thenewswheel.com/winter-weather-myths-does-road-salt-actually-cause-rust-on-cars/)

[AaronE]

I spray and pray. Even aluminum is not impervious to corrosion. Airports are unsalted because salt will attack bare aluminum so keeping a car clean in winter is a good way to slow the oxidation process. In Michigan and Ohio, I coin op blast our cars every one to two weeks.

Sent from my SM-G950U using Autogeekonline mobile app (http://r.tapatalk.com/byo?rid=87407)

[rangerbay]

Rinse the undercarriage with a marine product called "salt away".
There are several brands of similar products.
They help to alleviate the bonding of minerals to the surface.
It really works well

[Hermes1]

When I owned a house in colder, wet environments and where salt on the roads was common, I attached a lawn water sprinkler to a garden hose and drove forward and backward a couple times since crawling around on the wet cold ground was not a good experience and I suspect under such circumstances I doubt I was able to do it as thoroughly as I would like. I also from time to time, dare I say, went to a car wash with a under belly wash as part of the service with the expectation that come spring time a thorough detail would be required.

[TheMidnightNarwhal]

The materials you mention above may not be
susceptible to rusting, per se; but another form
of corrosion (oxidation) could/can be occurring.

•Therefore it’s advisable to rinse off your car’s
undercarriage, every now and then, during the
winter season when road salts are being used.

I, for one, won’t wait ‘til Spring to arrive
to ”de-salt” our vehicles’ undercarriages.



Bob

That's the problem, during the winter there is zero way for me to spray under carriage. Outside water is frozen.

My question is if doing it after winter since I don't do in in winter if there is any point.

[TheMidnightNarwhal]

Thanks guy but the main issue is that my car has a under belly. So rinsing under carriage is gonna be a PITA of having to lift the car up and at home I can't use a pressure washer in the winter...

So not sure what to do.