To stop a running, idling 6.0L Powerstroke if the exhaust is under say 1-3 feet of water?

 

The exhaust tip is under or the whole bottom of the engine is under?

If its tail down and just under water (say like on a boat ramp) I would think you probably could get it restarted.

If the whole thing is under water, and you'd have water back flowing up through the exhaust, i dont think you'd be able to get it started again

 

I took three different 6.0Ls through (up to 4 feet) of water this past week from the storms. Some running code, doing maybe 10-15 mph in 3 feet of water (makes a HUGE wave in front of the truck). Last night I took one of our three F-550s through maybe 2-3 feet of water, nice and slow (under 5mph) and coming out of it (maybe 1 foot of water) the engine died. It wouldn't turn over. I thought I hydrolocked it but a mechanic told me if the tail pipe was under (it was) it could shut down the engine and since the starter was flooded (it was) it could prevent an engine from turning over.

So right now I'm curious if I just hydrolocked a fire truck or maybe it needs to get drained out.

 

ouch

 

I would think you could have told the difference between a hydrolock (sudden stoppage) and an engine dieing. Sure hope it wasn't the former.

 

Like code58 said, I think you'd be able to tell the difference between hydrolocking and just dying. What confuses me though is that coming out of it is when it died. I have never had any vehicle die with only the tailpipe under. As long as your intake is above water, you should be good. I've driven through a creek in my jeep with water up to the top of the fenders (it was lifted 4"), and no shutdowns or anything. Here are a couple videos that show the ability to go under:


The other one I was going to put here of a F350 going underwater has some site inappropriate language, but the title is "2003 powerstroke pulls out 2010 duramax"

 

Well when my 4.2L hydrolocked years ago, it made quite a racket. The diesel was idling in 1st gear, going slow through the water, and I pressed the accelerator and it revved to about 1500rpm, bogged down to about 500, then went up again to 1500 hundred and just stopped. No noise or anything.

 

If you get even so much as few drops of water in the combustion chamber of any diesel motor the motor will most likely be toast. The tolerances are so close in a compression ignition engine that any water will hydro-lock the engine and cause substantial damage and you would never hear it.

 

Given the fact that the engine is an iron block, with stronger internals, and lower compression, spinning over only at low RPMs, do you think catastrophic engine damage (bent valve/piston/etc) would have been possible?

At either case, the truck is out of service and my chief is very upset with me, but I was just hoping the engine wasn't hydrolocked and totaled.

 

Y'all need to hep me here ....

If all we are talkin' aboot is a couple drops, won't the liquid water just flash to steam (which is still compressible) and cause no ill effects?

Hydrolock requires a substantial amount of incompressible liquid to do it's damage, IIRC.

BTW - what does cold water do to a hot turbo housing, or even hotter vanes?

Good luck Alex - no one should be angry with you given the work you did.


MGD

 

Your mechanic, may also be right but I know water in the combustion chamber of a diesel engine is bad juju no matter where it comes from. It's also possible the ECM or loose plug on the harness got a good gulp of water and shut the truck down. I bet your chief is not happy, but we all make mistakes and I'm sure your chief has made some before he made it to where he is. Go talk to a few of the guys on your squad and I'm sure everyone has stories like that.

 

That makes sense, but everything that I know about these motors is water is very, very, bad no matter if it comes in through the injectors or through the intake. Remember that diesels are interference motors and are not tolerant of any foreign matter that takes up more room than a couple specks of dust in the combustion chamber. The timing on a diesel is very important and if something throws that timing off for any reason such as water flashing to steam in the cylinder taking up the room that the atomized fuel is supposed to take up. What happens to the fuel when it's injected when you only have a minute amount of room for the air fuel mixture to begin with. Then throw in any boost from the turbo compressing things even further and you can imagine the bad things that can happen from that point forward.

 

restarting would be more difficult with the exhaust under the water, you'd have to force the water out the exhaust to get it started.

I'd think i'd unbolt the muffler back and see if it would start like that (assuming its on dry land now)

 

Here is the backstory, just so I'm not crazy:

I'm going maybe 3-5 mph, first gear, at maybe 1,200-1,500rpm. Water to the running boards. Give it a little gas, and the truck shuts down. No pings, bangs or anything. It shuts off just like I popped the clutch in first gear of my F-150 or someone reached over and turns the key, it simply dies. The starter gets a click click (like a dead battery). Some passerby hooks up to my winch and pulls me out. I sit for about an hour. I could not get the air intake fully apart, but I peered inside and it looked like the front of the intake grazed by some spray. I couldn't see the rear of the filter.

I wait an hour and here come a little late-90s Ford Aerostar. It goes halfway (deep part) and quits. Someone pushes him out, and he pops the hood and attempts to start it for the better part of an hour, but he's getting a "click click" like I am. About 15 minutes later, I hear it fire up and he is just revving him out. I ask him how he fixed it, and he just said: "I let the starter dry out and she fired right up!" and he took off.

So by now three hours have come by and here comes the two guys from the county yard. They don't ask me any questions, and go and attempt to start the truck. All they get is a "click" from the starter and tell me: "well you dun locked it up, it needs a new motor" (because motors run on internal combustion, i keep forgetting)

So today I went up to the county yard. She is sitting out back (boneyard). I go into the shop and there are the same two guys. I ask them if anything is new and I get: "nah, aint nuttin new, I dun told ya it needs a new motor!" I can tell they didn't even attempt to mess with it, they just unloaded it right where she sits. I wanted to go attempt to start it for kicks and giggles and I wanted to ask why he didn't pull the injectors or look at the starter, but I'm not going to argue with someone especially when I'm not sure.

I'm going to talk to my chief and at least suggest he ask the mechanic to pull the injectors and see whats what. I'm no expert here, but after talking with you guys, a mechanic in person, seeing an Aerostar (which is A LOT shorter than a jacked-up F-550!!!) make it out of there, and looking up a lot of videos- I'm sure that engine didn't get catastrophic damage.

 

Alex, let me get this straight. You were driving the truck through standing water that was at least 3 feet deep? The intake on a F550 is about 4-5 feet off the ground(I'm basing this off my F350) on the radiator support next to the drivers side head light. So if you were pushing any amount of water with the front bumper and with a big heavy duty winch bumper hanging lower than stock I would say that you were pushing a good amount of water and did indeed suck water into the motor if the filter box had any amount of water in it. With the turbo making any kind of boost there is a large amount of suction created just by the sheer volume of air the turbo moves at low boost (8-12PSI) think of the intake like a shop vac in that respect.