H3 - Water in Fuel Tank

[algy]

Curious to know if anyone has forded water in their H3 deeper than 24” and had issues with water getting into the gas tank. My H3 is stock with the adventure package, only thing aftermarket is the brush guard. The problem occurred after I got the tail end of my H3 submerged in a little over 3 foot of a fresh water stream. I was stuck and unable to get out and ended up having to shut down the vehicle and wait for a buddy to help pull me out.

The water line was well over the trunk area and particularly the left rear passenger seat. So the gas tank was completely submerged at this point for up to 45 minutes to an hour. When my buddy was able to get me moving, I was able to start up and assist in the extraction. Once out of the water let set there and let it idle, but only minutes after the extraction, I stalled out and never could restart.

We resorted to a tow chain extraction to the nearest roadside access so I could get it on a flat bed for servicing. In short the Hummer service diagnosed that I had water inside my fuel tank and had practically destroyed components and the pump leading to a replacement of parts and a complete flush of the engine with a high test fuel injector. They tried to pin the leak on a aftermarket locking fuel cap that I had installed, but after testing, discovered it to be secure.

It turns out; there is a small exit vapor lock on the top of the tank that is used to alleviate any pressure in the tank. I would think the lock would operate one way, allowing pressure to escape from the tank while keeping outside elements and air from entering. However, I am mistaken; the Hummer service is directing this component of the tank to be the source of water entry and voided my warranty for the repair because it sits higher than the 2 foot fording capacity of the vehicle.

Has anyone heard of this rubbish before? I guess the H3 will never get a snorkel package if all the components leak like a sieve and sensors burn out when submerged.


thnx
-Algy

[Viet Nam Vette]

Check this post out...

http://www.elcovaforums.com/forums/showthread.php?t=27428

Scroll down and see the H3's swim-en. Wonder if thses guys had your problem. But then again..they might not have been underwater as long as you.

Also..maybe our resident Hummer Engineer "F5FStop" will check in and advise you on the tank vent ..etc.

[Desert Dan]

Bummer I have never heard of the vent thing on the tank.

The time you were "under water "was part of the problem. How much gas was in your tank at the time?

Also if the gas tank was warmer than the water temp it may have sucked water in through that vent. Tha can happen when your diff goes under water.

Did they flush the rear diff as well?

Maybe I should always carry a can of fuel system water remover. It mixes with small smmounts of water that can then be burned in the engine.

[f5fstop]

All I can say is it appears the poster exceeded the design level that is noted for the H3, and thus components were compromised. My advice if submerging a H3 in water that deep for any length of time, the best thing to do is never start it until the fuel system is drained and all fuel tank components checked and/or repaired. That should alleviate any possible internal problems in the engine.

[Viet Nam Vette]

I'm sitt-en here thinking..and ..The I-5 is a Fuel Injeted motor with a high pressure feed line from the tank to the fuel rail at the motor. I would assume that there is a bypass return line back to the tank for unused fuel at the fuel rail.

Wouldn't there be some kind of a pressure relief on the retun side ..in other words ..why would they vent the tank.? It's supposed to be sealed when you replace the gas cap ..other wise you get a Check engine light if there is no pressure in the system.

BWTFDIK.....:jump: ..............Take it F5..:popcorn:

[evldave]

I'd think that you'd be better off leaving the engine running (and fuel system pressurized) as long as you are not drawing water into the air intake. Pressure of water (~14psi) going IN is gonna be less than fuel pressure (40-50psi?) going OUT...

[Wisha Haddan H3]

Might have ruined your catalytic converter too. Definitely check the diffs for water

[Steve - SanJose]

Okay, I've been warned about using my H3 as a submarine.

[Mr_Pat]

But I saw the comercial that says the H3 is a sub?????

[Steve - SanJose]

Brochure is clear about the water depth.

[algy]

Might have ruined your catalytic converter too. Definitely check the diffs for water

That was my 1st thought. Because I had staled out, I thought for sure I sucked up water and into the catalytic converter and ceased it. Using the trusty "tap w/ a wrench test" I found no sign of water in the pipes or muffler once the amphibious extraction was complete. Also during the land extraction I was being pulled up some steep inclines and again, no water was coming out of the exhaust during those climbs.

The diffs check is excellent, totally slipped my mind and you?re not the 1st to say it.

[algy]

Brochure is clear about the water depth.

Can't help but say that Brochures are for soccer moms.

[f5fstop]

I'd think that you'd be better off leaving the engine running (and fuel system pressurized) as long as you are not drawing water into the air intake. Pressure of water (~14psi) going IN is gonna be less than fuel pressure (40-50psi?) going OUT...

I will agree, if you KEEP IT RUNNING. However, once turned off, then make sure there is no water that will get into the system and start ruining parts.

[deserth3]

The vapor lock vent has to work both ways. THe returning fuel from the engine fuel rail will be warmer. Increasing pressure. Without the vent you would pull a vacuum when the fuel cooled off colapsing the tank.
Same thing with alltitude.

When it sat in the water the fuel would have cooled pulling a vacuum on the tank sucking in water.

Same thing happens with your rear diff. I recommend and oil change. Easy to do. Pull off the fill plug with a 3/8 wratchet. There's a drain plug underneath to drain the fluid. Again a 3/8 wratchet. Replace drain plug. fill up to fill plug.
Mine toook just over 2 quarts to fill the diff. I used Mobil 1 synthetic 75W90

[Hummer Guy]

All I can say is it appears the poster exceeded the design level that is noted for the H3, and thus components were compromised.

:iagree:

[algy]

Hands down, best Hummer forum I've come accross... thanks all! I'll stick around here.

[f5fstop]

Yesterday, I had my mind on other things, so my reply was incorrect. If you are submerged in water that deep, you should shut down the engine and wait to be towed. Why?

The fuel system is a closed system that prevents any hydrocarbons from escaping to the atmosphere, causing global warming, and peeing off Al Gore.
Technically, as the fuel system is running, a normally open vent solenoid allows fresh air to be drawn into the closed system to equalize the pressure, but the vent prevents vapors from escaping. Since vapors are being drawn out of the fuel tank and carbon canister via the purge line, and fuel is being pumped to the engine via the fuel line, if there was no air being sucked into the fuel tank via the vent, the tank would start to collapse. In other words, equalizing the system.

So, there is NO exit vent on the top of the tank, but there is an intake vent that is open while the engine is running. The vent solenoid, being normally open will allow some water to flow into the fuel tank if the engine is off and it is submerged; however, if the engine is off, this will not be a large amount of water. But if the engine is running, the vacuum inside the tank will suck in large amounts of water. This water will mix with the fuel, be pumped to the engine, causing problems all the way, until the engine can no longer run.

A unique problem that happens in areas with those small red spiders that are known to clog BBQ jets. They will build a web across the air intake vent, and air cannot be drawn into the fuel tank, while vapors are being purged into the engine. This creates a vacuum, and the fuel tank will shrink. Customer will see him fuel remain the same since as the tank starts to collapse, the fuel level goes up, but the customer eventually runs out of fuel, but gauge says the system has fuel.
Tech raises vehicle and finds a very strange looking fuel tank.:giggling:

Sorry for the incorrect answer yesterday.

[wannabeH3]

what are those little red spiders anyways? i always see those bastards and wonder if they are ticks or something

[RubHer Yellow Ducky]

what are those little red spiders anyways? i always see those bastards and wonder if they are ticks or something

Ask Marlin Perkins !!!

[Viet Nam Vette]

Ask Marlin Perkins !!!

Dat Mo Fo Be Dead

:jump:

[evldave]

Yesterday, I had my mind on other things, so my reply was incorrect. If you are submerged in water that deep, you should shut down the engine and wait to be towed. Why?

The fuel system is a closed system that prevents any hydrocarbons from escaping to the atmosphere, causing global warming, and peeing off Al Gore.
Technically, as the fuel system is running, a normally open vent solenoid allows fresh air to be drawn into the closed system to equalize the pressure, but the vent prevents vapors from escaping. Since vapors are being drawn out of the fuel tank and carbon canister via the purge line, and fuel is being pumped to the engine via the fuel line, if there was no air being sucked into the fuel tank via the vent, the tank would start to collapse. In other words, equalizing the system.

So, there is NO exit vent on the top of the tank, but there is an intake vent that is open while the engine is running. The vent solenoid, being normally open will allow some water to flow into the fuel tank if the engine is off and it is submerged; however, if the engine is off, this will not be a large amount of water. But if the engine is running, the vacuum inside the tank will suck in large amounts of water. This water will mix with the fuel, be pumped to the engine, causing problems all the way, until the engine can no longer run.

A unique problem that happens in areas with those small red spiders that are known to clog BBQ jets. They will build a web across the air intake vent, and air cannot be drawn into the fuel tank, while vapors are being purged into the engine. This creates a vacuum, and the fuel tank will shrink. Customer will see him fuel remain the same since as the tank starts to collapse, the fuel level goes up, but the customer eventually runs out of fuel, but gauge says the system has fuel.
Tech raises vehicle and finds a very strange looking fuel tank.:giggling:

Sorry for the incorrect answer yesterday.

Thanks for the clarification. Gotta love complex modern vehicles