Will a tail pipe draw water if it is barely under water on a boat ramp?

[jow]

Will a tail pipe draw water if it is barely under water on a boat ramp? I know or heard this is not good and the engine should be left running vs a vacuum killed. My fishing partners and I are aging and not judging good. What is the theory of water damage if a motor is killed with the exhaust pipe in water?

07, SR5, 2W Drive.

 

[wkeryder4]

No. Someone else that has done it may know better, but I don't think an exhaust pipe could ever act as an intake. The intake is what you would not want going under water. Also, I would make sure to leave the engine running.

 

[Burt]

You just answered your own question... Not good. Submerging anything can take it's toll.

 

[ebg18t]

Usually it doesn't cause an issue. I see folks do this all the time at the ramp. Make sure the engine is running. On most vehicles there is enough exhaust pressure exiting the pipe to prevent water from entering the pipe.

I watched a guy back his f150 almost all the way into the water. Water was pouring into the cab. Engine kept running and he drove the flooded truck right back up the ramp. Water was pouring from the cab, bed and everywhere..

With the location if the exhaust pipe on the 4runner I hope you aren't backing the truck that far into the water..

 

[JDSupreme]

depends on how steep the ramp is. mine has been submerged at least a dozen times with the engine running, im not worried at all as long as i keep it running

 

[aha2988]

for the second question though about what damage can be caused if the engine were to shut off while the exhaust is submerged.. All I've ever seen happen is the heads and cylinders flood with water when trying to start the vehicle with the exhaust submerged. The water floods the exhaust pipe if/when the engine shuts off, then when you crank the engine you have water right there at your exhaust ports so any little vacuum just floods the heads. I've personally only had hands on experience with this on a jeep 4.0L inline six cylinder.

The vehicle has to be in really deep water for this to happen though backing up on a boat ramp isn't really going to allow water to reach your engine. Any who when we've had it happen at mud bogs or what not it was a matter of pulling the spark plugs and between an air hose blowing and just cranking the engine letting the pistons pump water out of the spark plug holes the engine eventually would unflood and with a little starter fluid fire right back up.

now if you were to continuously try to crank the engine after you've had water enter the cylinders and didn't removed the spark plugs, the water will not allow the pistons to travel a full stroke. The water is not as compressible as gasoline is so pressure builds causing head gasket failure, cracked blocks. The piston rods can bend, main bearing failures, damaged heads, etc. It can be catastrophic if the engine is hydrolocked at running speeds such as if water was sucked into the intake or a head gasket failed allowing coolant to flood a piston.

I googled it just to make sure i wasn't mis informed or just passing some wives tail that I've heard along and ironicly the picture on Ehow on this subject is a picture of a 4th gen V8 engine lol..
What Gets Damaged in an Engine Hydrolock? | eHow.com

 

[Sungod]

The exhaust is hot. The gases inside are hot. When they are cooled by the water they contract which creates a vacuum. You will draw some water in, but unless you are real deep, it wouldn't draw it all the way back. It is best to keep the motor running.

 

[Nathana92]

You could always cut the exhaust pipe right after the muffler and weld on a dump in front of the rear axle. I doubt that you'll ever back down a boat ramp where water is up past the rear axle and high enough to submerge the exit. Then you wouldn't have to worry about it at all.

 

[jow]

Thanks for all the replies! The “very tip” of the pipe was in the water. I did kill the engine but never would have if it was confirmed I was in the water (even at that angle).

What is the little resonator/muffler looking item just ahead of the tip? I was not almost there and wondered if it would resist water going past that point.

 

[tollboothwilley]

just keep the motor running while you are in the water - you'll never have to worry as long as the whole vehicle isn't submerged.