Hey everyone,

We have a 2024 CX5 with 10,000KM on it. Was adding washer fluid the other day and noticed alot of white reside in the engine bay. It's not everywhere, but it is certainly there.
We are also in an area where salt is used on the roads, so I'm not sure if it's salt or dried coolant, or just dirt. I think I would have noticed this before now if it was salt but maybe not. I checked our other car (2013 mazda 3) and there is nothing like that in the engine bay, and it gets driven a lot more.

The overflow tank seems at the right level. The temp cooled off a bit here so it might be SLIGHTLY lower than before. No warning lights or anything.

Any idea?

If I take a wet towel and wipe this off, would it turn back to green if it was coolant?

Thanks everyone
Dave

 

No, it's summer here right now(actually fall today lol), so if it is salt, that's been there for months Obviously this could be the case but just never really noticed..
I'd have to look to make sure all the shields are under there, but I am assuming they are, unless Mazda removed them for some reason.

I thought dried coolant was white? But maybe I'm totally wrong

I mean I know the 2013 mazda 3 and 2024 cx5 are different vehicles, but my shields under the mazda 3 are barely there (warped, sagging etc) and still don't have anything like this in the engine bay, which is what made me think it might be coolant.

My gf has the vehicle right now, so I'll check this all out tonight

Thanks!

 

I see in your post under from: Nova Scotia, where obviously there is no salt being used on the roads now.
I live in Maine and that does look like salt mixtures they use on our roads but only in the winter, but I can't definitely say that for certain.
I would also point out living on the coast I can occasionally get that same salt residue from the thick fog we get especially if the vehicle has been run in it.
When engine cools down the salt in the fog tends to condensate under the hood much like the harvesting ocean salt process.
Not saying that is your issue but being in Nova Scotia I suspect, like the coast of Maine, there are very few places in your province that don't get fog.
I clean under my hood about once a month, which means I never get much buildup.

Welcome to the forum.

 

I try not to make a habit of licking my engine, but it did cross my mind this time hahaha

 

Wasn't there something about licking engines and hallucinations...

 

Its not coolant. this I am sure of looking at the pictures. Nor do I believe another problematic substance other then it is fugly looking for an engine compartment

If it is powdery to the touch, then this can happen from the vehcle parked on a wet or moist surface and the cooled generally in the morning at sunrise then in some area's of the world as the sun continues to raise and warms the ground the that moisture will enter the engine compartment and basically everything under the vehicle but in the case of engine compartment this warmed moist air creates an under-hood environment the reacts to and causes that powdery substance to form on everything. Most of us have likely seen this more often on a vehcle parked for some time and the brakes and suspension can have this same white powdery substance but many only see the oxidation and rust instead of that powder.
Rinse the engine off with a garden hose and use a wide sprat not the high pressure. Then any remaining powder can by wiped off. You can use and engine wipe that will bring back the looks of the rubber and aluminum and other under hood parts. This can also happen even with garage kept vehicles under similar circumstances. Remember let the wet engine dry for a while before attempting to start it. Thios will prevent the effects of condensation to form in electrical components.

If the white powder is left to long it can discolor some parts like aluminum.
Below is the after effect of what I described, while it looks bad the aluminum can easily be shined back up with a little NEVER DULL polish cleaner.
Sorry I don't have an engine picture that I can find right now that will look almost exactly like the picture in the first post.

 

Thanks for the detailed reply Callisto

It's definitely gritty...I would not call it powdery. I'll look at it again tonight and post what I find!
Thanks!

 

Yes I suppose we can call it gritty as well. Nevertheless it is more common that many think.
So I went out and just took these pictures. As a simple example, my engine compartment at the beginning of summer looked like your Mazda engine compartment. I live in Northen CA. I have since washed the engine a few times as well the undercarriage and removed most of the white substance. If I had to guess based on feel and touch it is byproduct of minerals formed from the moist and warmed air that can be under special conditions formed. Never really though to run it over to the lab for analysis. HA! I still have some remaining area's I need to cleaned up.


These are all after the rinsing and some minor detailing

I suppose feeling it for response info it does feel a bit grain like?






The under carriage I sprayed with simple green and then with a garden hose and universal common sprayer rinsed it off.




one last thing do not taste for salt. Aside from many mineral deposits can taste salty some are actually poisonous.