Hey Scotty and fellow Scotty-followers,
I have a rather general question: can simply driving on a busy highway in heavy rain damage the engine? I just did that, and noticed that air had pretty high water vapor content all over the place, so I was wondering whether water (in the form of overly humid air) could get into the ignition chamber (and possibly even mix with engine oil somehow and dilute it). I do not notice anything unusual; the car (2009 euro Ford Focus 1.6L duratec vvt 5-spd manual with 116k miles on the clock) runs just fine.
Should I just check whether my air filter is wet if I'm still worried, and forget about it if it's dry or just slightly wet? (I haven't had a chance to check it yet as it's still raining and I parked the car outside.) If the air filter and the inside of its box is any wet, I'd rather change it alongside with engine oil (and oil filter). I know, this may sound radical.
Any thoughts are welcome.
Thanks in advance!
Best regards,
Dan
No worries. Vapor and droplets won’t cause problems. In fact, back in WW2, fighter planes had water injectors that gave a short burst of power (there was a discussion on this a few months ago that explains the engineering).
A little water in the air intake will usually drain out the bottom, and if a little makes it to the cylinder it will evaporate and blow out the tailpipe.
The risk comes from driving through standing water that overtops the intake. If you get a significant liquid water volume in the cylinder then you can damage the engine. Gas compresses but liquid doesn’t. It’s called hydro locking the engine and leads to bent pushrods. Usually requires rebuilding the motor.
Only if you have messed around tuning and have pod filters hanging outside in open air! 😂
On a serious note Ford Focus(&Fiesta I believe) driver's need to know that the air intake box is mounted In front of the left hand front wheel only about 12 to 18 inches above ground level, and as such are TOTALLY at risk of engine hydrolocking destruction by driving through 1ft of water!!
Hope this can save owners of these cars big $ damage.
Don't hold me to it, but I'd be inclined to think that the Mondeo could be the same.
can simply driving on a busy highway in heavy rain damage the engine?
Good question. If it did , we would all be in trouble.
No, the engineers have thought of that. The factory engine air inlet is located in such a way that it doesn't ingest much rain. If any does get in then ...
- the bends in the intake cause the water to drop out
- the engine generates a lot of heat which evaporates moisture
- the air filter has so much air going through it that it dries out very quickly
- a bit water vapor in the combustion chamber doesn't hurt the engine. In fact, water is the main byproduct of gasoline combustion. For every lb of gasoline your car uses, it produces almost 1.5x that weight in water vapor.
- It's true that humidity does displace a bit of oxygen though, so technically, there is a slight loss of maximum power, but you won't notice it.
@dad2lm2 @aussie-car-reviver @mmj thank you for your response!
I appreciate your detailed explenations. They are of great help!