Hydrolocked but runs

[jlawles2]

Long story short, Cold air intake was under water long enough to pull water into the engine. Engine was at less than 1,000 rpm when hydrolock happened.

Let engine sit, drained intercooler and other things. Engine starts, runs, but has bad white fuel smoke from exhaust. Not loosing water or oil. Not making water or oil. No hard hose and no bubbles from overflow bottle.

Also no strange noises from engine. Drove it home after the hydrolock.

Ran compression test. 7 cylinders at 400 psi one at 300 psi. Gm spec says min cylinder temp is 300 psi. From everything I have learned over the years, more than 10% difference is not a good thing. The cylinder with low compression is also showing balance rate of 15.0 and I am getting a non light setting code of fuel rate adjustment out of specification (may be different but close).

What are the chances of bad injector? Out of adjustment valve? or Bent rod?

 

[duratothemax]

Bent rod most likely.

GM says minimum spec is 330psi. But 330psi is absurdly low, I dont know how GM came up with that number.

Most healthy stock duramax's are 410-430psi. Anything below 380psi I would say you have problems.

 

[hondarider552]

My #1 rod was at 200psi for compression test when it went limp.

 

[TheBac]

Bent rod. My condolences.

 

[jlawles2]

I was thinking bent rod. Just needed to run the compression test to confirm my thoughts. now to pull the motor and start the rebuild.

Anyone suggest a machine shop in the Houston Area?

 

[quinton]

Call and ask relentless diesel. They can give you a good shop. I'm using a shop up here in Springtown.

 

[S Phinney]

I would suspect bent valves first then rods.

Sent from my DROID RAZR using Tapatalk 2

 

[chevyburnout1]

Any pics of this CAI under water? Sounds like a story behind that one lol

 

[Dozerboy]

There are some good guys in the Lake Charles, LA area. I like Chris at Relentless and he does good work, but I don't know that he would be my first choice.

 

[jlawles2]

no pics of CAI under water. Was headed to hunting grounds. Have been through the hole before with no issues. This time, went slow as truck was full of stuff and I think the back flow into the hole might have caused the waterlevel in front of the truck to cover the intake. Blocker plate was installed making the majority of the air come up from just under the front bumper.

For machine shops, I found a shop down in Bay city. He does work for Renegade diesel and auto. He can long block it for me, at a cost of $100 hr. I only need them to get the mains and rod bearing to spec.

IF bent rod(s) which stock rods are best? LLY, LBZ, LMM, LML and are they drop in replacements? Thinking about going with delipped stock pistons or delipping the current if they are not damaged.

Any suggestions?

 

[maxxin-n-style]

May want to look into keying the crank and cam also. .
drv performance in tomball does great work also!! Id go with him before id go with relentless imo..

 

[jlawles2]

Got cab off today and pass side valve covers off. No signs of issues. Tomorrow going to work on getting the head off the pass side. from there will determine next course of action.

Which bolts need to be replaces since the are TTY? Heads I know and flywheel to crank. Any others?

 

[ecc_33]

My money is on a bent rod. Might as well pull the engine and take it all apart if your this far.

 

[jlawles2]

Yeah I figured as much when it happened. Completely surprised that it actually started and ran.

Hopefully i find the issue today. hoping its only a bent rod and nothing else.

 

[TheBac]

A duramax will start and run (not well) on a busted crank in some cases. There's been a LOT of us that drove our trucks on bent rods and didnt know it until something made us suspect there was a problem.
Id bet most all these new guys claiming they're running around with a 600/650hp stock motor are sporting bent rods right now.

 

[jlawles2]

Rod is bent bad. Bottom of piston actually contacted crank. Crank shows no signs of damage.

And its number 5. The one with low compression.