YACT: How high can water be before it stalls the engine?

bolido2000

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Dec 3, 2001
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I'm seeing a lot of people with cars stucked in the middle of the road cuz of the rain. How high can water on the road be before is too dangerous to drive and get stucked? Middle of the wheels?
 

Eli

Super Moderator | Elite Member
Oct 9, 1999
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It would have to be over the air intake to kill the engine.
 

Heisenberg

Lifer
Dec 21, 2001
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It usually won't stall the motor until it gets over the exhaust and/or well into the engine compartment. The major danger with driving in water is the car being pushed away by the water. That will usually happen first, especially in a flood situation.
 

Lonyo

Lifer
Aug 10, 2002
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Or if it's high enough to stop the spark plugs working (in a petrol engine).
 

CraigRT

Lifer
Jun 16, 2000
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depends on where the intake is.
and once water gets into the intake so that it's literally over top of the intake and totally flooding the car, prepare to pay for a new engine, as you've just waterlocked your old one. (ruined)
 

Electric Amish

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Oct 11, 1999
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Originally posted by: Eli
It would have to be over the air intake to kill the engine.

Would it not kill it if it blocked the exhaust sufficiently enough that the exhaust couldn't discharge?
 

Eli

Super Moderator | Elite Member
Oct 9, 1999
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Originally posted by: Electric Amish
Originally posted by: Eli
It would have to be over the air intake to kill the engine.

Would it not kill it if it blocked the exhaust sufficiently enough that the exhaust couldn't discharge?

Yeah, it would.. it probably would at idle.

I would assume most engines would be able to push the exhaust out through the water revved a little though. I have seen cars with their tailpipes submerged on news footage.. bubblebubble..
 

bolido2000

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Dec 3, 2001
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Originally posted by: Electric Amish
Originally posted by: Eli
It would have to be over the air intake to kill the engine.

Would it not kill it if it blocked the exhaust sufficiently enough that the exhaust couldn't discharge?

That's what I'm thinking. I guess the rule of thumb is if it can cover the exhaust pipe.
 

Pepsi90919

Lifer
Oct 9, 1999
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Originally posted by: Lonyo
Or if it's high enough to stop the spark plugs working (in a petrol engine).

not only would the spark plugs not work, the engine would sieze.
 

Electric Amish

Elite Member
Oct 11, 1999
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Originally posted by: bolido2000
Originally posted by: Electric Amish
Originally posted by: Eli
It would have to be over the air intake to kill the engine.

Would it not kill it if it blocked the exhaust sufficiently enough that the exhaust couldn't discharge?

That's what I'm thinking. I guess the rule of thumb is if it can cover the exhaust pipe.

Not just cover it, though. It would have to produce enough pressure to cause back-pressure into the engine.
 

Vic

Elite Member
Jun 12, 2001
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Depends entirely on the car. Could be a couple of inches of water or it could take 6 feet (in a tall 4x4 with a snorkel intake :p). Usually a car is safe if the water is less than 1 foot deep and the puddle is relatively short, like 20-30 feet (it rains so much here, I've driven through those all the time). Beyond that would not be safe, regardless of how slow you drive.

Generally, it's when (if you're lucky) any of the ignition components get wet enough to cut off spark to the engine, or (if you're unlucky) when the air intake gets wet and lets water into the engine. The latter is very bad, because if water gets into your engine, it does not compress at all (called "hydrolocking"), and breaking/bending of connecting rods is likely. The good news is that full coverage insurance should cover your short block.

One more thing, cars with CAI's (cold air intakes) are especially prone because the bare cone intake is located in the fender.
 

Mutilator

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Aug 22, 2000
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Safest thing to do is NEVER drive through standing water no matter how deep or shallow you think it is. They stress this time and time again on the local news because it takes less than 2ft of water to float a car away. Most deaths during severe weather is due to people drowning in their cars after they tried to cross a flooded street.
 

iamwiz82

Lifer
Jan 10, 2001
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Originally posted by: Electric Amish
Originally posted by: bolido2000
Originally posted by: Electric Amish
Originally posted by: Eli
It would have to be over the air intake to kill the engine.

Would it not kill it if it blocked the exhaust sufficiently enough that the exhaust couldn't discharge?

That's what I'm thinking. I guess the rule of thumb is if it can cover the exhaust pipe.

Not just cover it, though. It would have to produce enough pressure to cause back-pressure into the engine.

the water would have to be very deep for that much pressure to exist. If you cover the exhaust with water, all it will go is glug and will continue to run. If you turn it off, though, you will be in trouble as the water will run through the exhaust and into the engine, if its deep enough.

The highest depth water I have been in has been about 40 inches, and I survived. Basically, it depends on how much of a splash is created to soak the air filter and cause hydrolock.

this is alittle too deep

he survived though
 

Vic

Elite Member
Jun 12, 2001
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Originally posted by: Mutilator
Safest thing to do is NEVER drive through standing water no matter how deep or shallow you think it is. They stress this time and time again on the local news because it takes less than 2ft of water to float a car away. Most deaths during severe weather is due to people drowning in their cars after they tried to cross a flooded street.
Try never driving through standing water in Western Oregon and Washington during the winter months, and you'd never get out of your driveway. In fact, we're just about due for the constant every-freakin-day rain that always hits this time of year.
Yep, here it comes....:(
 

Eli

Super Moderator | Elite Member
Oct 9, 1999
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Originally posted by: Vic
Originally posted by: Mutilator
Safest thing to do is NEVER drive through standing water no matter how deep or shallow you think it is. They stress this time and time again on the local news because it takes less than 2ft of water to float a car away. Most deaths during severe weather is due to people drowning in their cars after they tried to cross a flooded street.
Try never driving through standing water in Western Oregon and Washington during the winter months, and you'd never get out of your driveway. In fact, we're just about due for the constant every-freakin-day rain that always hits this time of year.
Yep, here it comes....:(

Yup..

It's still a day away though. The rest of today should be OK. We may get a shower in the next couple of hours out of the low off the southern oregon coast, but the real rain won't start until tomorrow..
western pacific satellite