Well what happens in the summer when it's 100F out and a cool thunderstorm comes through and hits your engine with cool water? Nothing. Engines are tested by engineers to handle abuse. It pretty much boils down to not power washing your engine and directly drilling critical areas with heavy water. Like I said, every time I drive through heavy rain and pop the hood, the engine is a mess bc water/dirt etc. is going all over the engine. You can see the road from the engine bay so driving through a puddle alone will get your engine wet.
Is is safe to hose off the engine?
- Thread starter buster
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Buster,
The engine is running it can withstand the shock of the cooler water. Its not that great of an idea to hose the motor with it running, but its a better alternative than hosing a HOT motor thats not running.
If you take a hot glass from the dishwasher and place it in the freezer it will crack. It may not happen to every glass all the time, but it does happen. Its rapid contraction. Same thing with a metal frying pan. If its hot and placed in cool water, rapid contraction of the metal will not allow all particles to realign therefore the bottom will bow out or in to compensate. Essentially that metal pan is ruined.
Combustion engines are composed of many disimiliar materials that are mated to one another. These mating surfaces have gaskets. Its important for these mated surfaces to remain flat to within .001 or less. All these surface expand and contract at different rates. You spray cool water on a hot area of a motor that is not running you will get rapid contraction of the materials. These problems tend to show themselves as cracked exhaust manifolds, warped intakes, leaking fuel pumps (diesels), leaky headgaskets and more.
Another way to think of this is when you hit a hot motor with a pressure washer you are only hitting maybe 1 square foot of surface area at a time, SHOCKING this specific area into contraction when other regions of the motor are still in the expansion phase.
I will stick with a COOL motor or slightly warm.
The engine is running it can withstand the shock of the cooler water. Its not that great of an idea to hose the motor with it running, but its a better alternative than hosing a HOT motor thats not running.
If you take a hot glass from the dishwasher and place it in the freezer it will crack. It may not happen to every glass all the time, but it does happen. Its rapid contraction. Same thing with a metal frying pan. If its hot and placed in cool water, rapid contraction of the metal will not allow all particles to realign therefore the bottom will bow out or in to compensate. Essentially that metal pan is ruined.
Combustion engines are composed of many disimiliar materials that are mated to one another. These mating surfaces have gaskets. Its important for these mated surfaces to remain flat to within .001 or less. All these surface expand and contract at different rates. You spray cool water on a hot area of a motor that is not running you will get rapid contraction of the materials. These problems tend to show themselves as cracked exhaust manifolds, warped intakes, leaking fuel pumps (diesels), leaky headgaskets and more.
Another way to think of this is when you hit a hot motor with a pressure washer you are only hitting maybe 1 square foot of surface area at a time, SHOCKING this specific area into contraction when other regions of the motor are still in the expansion phase.
I will stick with a COOL motor or slightly warm.
I have been hosing off my engine bays for years. I feel more comfortable with foriegn cars than American. The electrical connectors on *** cars are better. I simply wet the engine compartment. Spray it down with Castrol Super Clean. Let soak for 5 minutes, then hose off. Start engine and drive for 10 minutes. Its that simple. JUst dont spray w ater directly onto certain items, Alt, Ecu, etc, common sense should come into play. If you notice with Toyota, All of their connectors are waterproof if they are not inside the car.
Same with American cars. I've disassembled enough electrical connectors on American cars to know.
Has ayone had any trouble washing off their 4.6L Ford engine? We have a '97 Town Car with the 4.6L engine with no major oil or grease on it but would just like to clean it up a little. Just wondering if it would really be worth the risk.
Interesting details. I was contemplating "detailing" the engine compartment on my 88 Dodge Aries because it is quite messy, it's got spider/cob webs in some parts of the compartment LOL (particularly the front-passenger nose of the car, where there are few moving parts, nor fan/intake blowing to "clear it out" per se....). But with all the sensors under the hood, I think I'll pass, or just take it to a detail shop and let them take the responsibility (they break it, they buy it lol...they should know what they're doing right? lol).
Being an 88 It's bound to have some "open" electrical components that aren't completely sealed/waterproofed....that likely WERE waterproofed/sealed, but has simply worn off or disinntegrated through the years
Being an 88 It's bound to have some "open" electrical components that aren't completely sealed/waterproofed....that likely WERE waterproofed/sealed, but has simply worn off or disinntegrated through the years
The risks outweight the rewards. I just use my air compressor to blow out any sand that accumulates and then just use some armor all cheapo shine on the plastics and hoses. IMO the engine bay is the last place you want water.
Wow...some of you guys better not EVER buy a car with any kind hood scoop then.
The Foresters pretty much acts as funnel for rain water and yet it still works! Imagine THAT!
There is nothing wrong with washing a motor hot or warm. You cannot remove enough heat in the engine quick enough to cause a problem. There just isn't enough surface area unless you dunked the car in a lake.
This thread reminds me about the convo I had with an old guy regarding oil weights, he seemed [censored] frightened of anything other than 10w30.
The Foresters pretty much acts as funnel for rain water and yet it still works! Imagine THAT!
There is nothing wrong with washing a motor hot or warm. You cannot remove enough heat in the engine quick enough to cause a problem. There just isn't enough surface area unless you dunked the car in a lake.
This thread reminds me about the convo I had with an old guy regarding oil weights, he seemed [censored] frightened of anything other than 10w30.
My thought has always been that if spraying the engine compartment with water is going to cause problems, it was a problem waiting to happen anyway.
The cars with hood scoops direct the air, and if raining, the water, in a deliberate fashion be it over an inter-cooler or intake system. It doesn't allow incoming air/water to get all over the place and on electrical connections.
Ever wondered why Ford put that rubber cover over the distributor on the 5.0L engines?
You'd be surprised what gets wet at high speed or sitting in a parking lot.
I had quite the puddle on my intake manifold one day after sitting in a downpour. I only noticed because I filled up the windshield washer reservoir. Yes electrical connections were yet and yes the car worked fine.
I had quite the puddle on my intake manifold one day after sitting in a downpour. I only noticed because I filled up the windshield washer reservoir. Yes electrical connections were yet and yes the car worked fine.
And when you drive through a deep puddle?
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