I Sank my 2003 Z71 Tahoe

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matsmiley

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Greetings!

This is my first post. I recently hydro-locked my Tahoe. I have already cleared all the water and am currently in the process of changing all the fluids.

The main thing I need to know is why I can start the motor with starting fluid but can’t get it to idle. I’m think maybe water got in the gas tank and I’m draining that now.

I also need to know how much fluid to put back the front and rear diff and transfer case.

This is my first Z71 but I’ve had a 05 lt tahoe that I got to almost 400k before losing oil pressure.

Thanks in advance.
 

alpha_omega

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Greetings!

This is my first post. I recently hydro-locked my Tahoe. I have already cleared all the water and am currently in the process of changing all the fluids.

The main thing I need to know is why I can start the motor with starting fluid but can’t get it to idle. I’m think maybe water got in the gas tank and I’m draining that now.

I also need to know how much fluid to put back the front and rear diff and transfer case.

This is my first Z71 but I’ve had a 05 lt tahoe that I got to almost 400k before losing oil pressure.

Thanks in advance.
If you suspect water in your tank, it could also have water in your fuel vent hoses. Have you recently checked the spark plugs, o2 sensors, grounds (ALL of them), cleaned the MAF sensor, throttle body and checked the fuel rail/injectors?
These could all be fine, I guess I’m not sure what exactly you mean by “sank my 2003 Tahoe” or how bad it was.

I used to live down in NC and the entrance road to this subdivision I was at would get flooded during bad hurricanes. There were only a couple of us that could get in/out until the rain stopped and the water level went down. I’ve had some close calls, but I never slowed down or let her get too far under. Just keep swimming…
 

OR VietVet

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Welcome to the forum from Oregon.

Water water water everywhere. If idled fine before and now will not, IT"S THE WATER. Start with the obvious, and you have and I suspect the fuel in the tank. You SHOULD drop the tank and clean out. You vent systems are effected as well.

Just how deep was the water and how high up on the truck did it come? Yes, I have to ask. What the hell were you thinking!!!!!!!!!!
 

B-train

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We need some more specifics about the events.

1. How deep of water?
2. Was it running and then stopped due to hydro locking?
3. Have you taken a fuel sample from the rail? Or as most have stated, drained the tank and see how many guppies come out?
4. What have you done to facilitate the drying out process?
 

Alex_M

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How's the engine sound when it's running on spray? Almost anything will run on ether, not a good diagnostic. Squirt some gas down the intake and try that. If it hydraulic'd the motor while running you very very likely have mechanical damage. I hydraulic'd one on the starter a few months ago, injector stuck open while off, and it bent a connecting rod. Bent valves and bent pushrods are also common.
 

Joseph Garcia

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Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving clarifying questions and sage advice from the knowledgeable folks on this Forum.
 

Mudsport96

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Yeah, so what rpm was she turning when you went swimming? If it was at idle, she MIGHT be okay. I drown a 4.3 years ago that just needed a good drain and dry. Also killed a 302 that was at full song when the nose dipped.... yeah, liquids don't reasonably compress.
It may just be water in the fuel system, ecm, wiring, blah blah blah.

You want to drain both differentials, transmission and tcase, and yes the engine.

Please keep us updated.
 

Hobert

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matsmiley

matsmiley

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We need some more specifics about the events
1. How deep of water?
2. Was it running and then stopped due to hydro locking?
3. Have you taken a fuel sample from the rail? Or as most have stated, drained the tank and see how many guppies come out?
4. What have you done to facilitate the drying out process?

Sorry for the late response. I’ve been real busy. However here are the answers.


1. How deep of water?
The front end got up to the bow tie.
2. Was it running and then stopped due to hydro locking?
Yes.
3. Have you taken a fuel sample from the rail? Or as most have stated, drained the tank and see how many guppies come out?
I’ve drained the tank and had the pump replaced a few weeks prior to this happening. Before drinking the tank I was still getting fuel to the motor.
4. What have you done to facilitate the drying out process?
Pulled plugs, cranked and got all the water out of the motor and exhaust, replaced all fluid except for the diffs and transfer case. I’ve drained them but still trying to find the proper amount to put back in. Since there was water in everything it was hard to measure.

Thanks for the help.
 
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matsmiley

matsmiley

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Hey everyone, thanks for the responses!

To catch y’all up. I pulled the plugs and cranked all the water out of the motor and exhaust. I have also drained all the fluids from everywhere possible and let them dry for several days. I need to know the specs on how much to put back into the transfer case and diffs. I have also drained all the fuel.

It died at idle and when cranking there’s no rod knock and no metal in the oil when drained. The front end got up to the bow tie and the back just over the wheels (which are ballistic 20’s with dynapros)

When researching I think a ground may have came loose when getting pulled out.

Thanks again for everyone’s help.
 
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matsmiley

matsmiley

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Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving clarifying questions and sage advice from the knowledgeable folks on this Forum.
 

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matsmiley

matsmiley

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Can anyone please help with the amount of diff, transfer and trans case fluid amounts I should put back into the truck?

Also I think a ground may have came loose because when cranking everything sounds fine and will fire up with starting fluid but not idle. No bad sound coming from engine and no metal in the oil.

Thanks again for everyone’s help!
 
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matsmiley

matsmiley

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I do not know exactly off the top of my head, but I THINK about 3 quarts rear diff 3 front both gear oil and 2.5 to 3 quarts for transfer case, 4 button will be special fluid and 3 button should just be atf.
Thanks for the help! When you say ‘3 or 4 button’ are you talking about how many buttons are on the dash for 4wd? The transfer case fluid was blue and the atf was red.
 

Fless

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Thanks for the help! When you say ‘3 or 4 button’ are you talking about how many buttons are on the dash for 4wd? The transfer case fluid was blue and the atf was red.

You must have the AUTO button on your 4x4 switch -- the blue fluid is AutoTrak II and that Tcase takes just under 2 quarts.

Be sure to crack open the FILL plugs on the Tcase and diffs before you drain them. Make sure you'll be able to ADD fluid, before you drain them...
 
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matsmiley

matsmiley

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Just an update for everyone:

She is good as new and runs like a dream!

Only issues from the flooding was a CEL from the knock sensors. That I assume got rusted when the 50+ gallons of water got sent through the system. I plan to fix them but if I’m going to replace them I want to do a whole to intake system and maybe even pull the head covers to see how the engine is looking.

The water that got in the transmission I tried to just cycle out but a flush was the only way to get the fluid transparent again. It doesn’t slip but when cold the 1-2 shift is a little rough.

Other than that after dropping the tank and flushing all the fluid (complete trans flush) which isn’t that hard to do yourself, especially if you have an extra hand. Everything is good to go.

The only issue now is that the 4wd click and pulls to the left when engaged. The click isn’t from the transfer case. It almost sounds like rod knock at high speeds.

If anyone has any info on that, please, let me know!

Thanks everyone for the help during the fix!
 
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