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Blown Head Gasket Recovery (no longer) - Massive Engine Failure (!)

adf5565

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Sh*t hit the fan today on my way back from a weekend camping trip and I blew a head gasket.

I was climbing a decent hill (but not the steepest/longest I encountered) on the trip home and noticed what sounded like a very minor exhaust leak. This even started before I got to the hill and was quiet that I’m not sure I would’ve heard it if I had the radio on. After about a minute (and 90% of the way to the top of the hill) all hell broke loose and it got very loud for a second or two before stalling out. After that the motor was locked and wouldn’t turn over. Coolant temps were barely even up to 195 as I had just a couple minutes beforehand left the campground.

Upon initial inspection at home there was over 2 gallons of coolant in the oil which caused oil (and possibly coolant) to enter the intake which most likely got into the cylinders which is why it wouldn’t turn over. Glow plug for cylinder 5 was wet so right now that seems to be the suspect location of failure.

I’m worried about other potential damage to the internals from it locking up. Is this something that commonly occurs? Or what are other watch outs as I’m taking it apart to check for other issues? I’m just not sure what else could potentially be wrong. Bent valves? Any other advice that you can provide would be greatly appreciated.

A little background- this is a 6.5 Optimizer with 3500 miles. I originally thought I was just paranoid but now that this happened I think my head gasket issue has been a while in the making and it wasn’t this hill that was the root cause. Even from the beginning (new) the motor seemed to use a small amount of coolant. I Couldn’t find any leaks but also never noticed white smoke or smelled of coolant so I wasn’t sure what to think. And then earlier this year for the first time I checked the radiator and saw a couple tiny bubbles making their way up. But the top radiator hose didn’t get seem to get hard. So definitely had mixed signals.

Here I am after someone thankfully towed me out of the middle of the road to a pull off where I could wait for help.

IMG_2500.jpeg
 
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NDT

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OMG. I don't think you have a blown head gasket initially, (might be now), I think a huge crack opened up in the cylinder wall. All the parts you want to reuse need to be checked for damage and straightness. Never heard of this failure mode on a 6.5 myself. I would be very upset after going through the trouble of finding a GEP engine to supposedly eliminate the cracking issues found in the GMs.
 

87cr250r

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It's locked up solid? This sounds like a main web failure. That shouldn't happen on an Optimizer. The Optimizer engines will still crack heads and they still blow head gaskets but they don't crack the blocks like the used to.
 

Don-T

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Sorry to hear you are having this trouble. I thought the Optimizer engines were supposed to be bulletproof? I hope it is not as bad as it sounds. I will be watching this closely. Good luck with it.
 

nyoffroad

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Hope for the best but prepare for the worst. I envision some bent rods and maybe a bent/twisted or broken crank. On the good side no valves should be damaged unless they ate some debris. I know, I'm not helping. Truely are sorry this happened.
 

adf5565

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Well this is no longer a head gasket recovery thread, now is a what the h*ll happened thread as the motor has been destroyed. I got the motor pulled and somewhat disassembled and looks essentially like a bomb went off.

Cylinder 5 connecting rod is blown apart. Piston is cocked in the cylinder and the block wall is blown apart. What’s left of the connecting rod was forced into the bottom of the block and blew that out. Exhaust valve and push rod are bent.

Can someone help me ID what happened? My original assumption was that the head gasket catastrophically failed which caused a bunch of coolant to enter the cylinder which during the compression stroke made bad things happen. Granted there was coolant in the cylinder but im not sure if that was more from the cylinder wall blowing out.

Looking at the head gasket I don’t see any apparent signs of damage. The lower part of the head (in the pic) where the cylinder is does look a little “washed” but the gasket itself, fire ring, and fire ring imprint do not appear to have any signs of damage.
 
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adf5565

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Where are the nuts?? Highly unusual that the nuts are no longer threaded on.
The mangled one was missing and the others I took off so I could rotate the crankshaft to remove the last torque converter bolt.
 

87cr250r

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The piston skirt failure happened first. The pistons cocked in the bore and made several impacts with the head. A rod failure would have left the piston in one position. A stuck injector can cause a piston failure like this. I suggest pulling the other pistons to check for signs of overheating.

I might be interested in your heads.
 

gringeltaube

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Can anyone explain this mark on the exhaust valve?
1717683351143.png
A ½”-lockwasher would be about that size... But since this mark is so perfectly centered on the valve head and there are no evident signs on the corresponding piston, I doubt that the engine "ate" a washer... (?)
 

87cr250r

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And where would a split lockwasher come from? Nobody uses those things, right?... Right?

Do notice how clean and wet the failed cylinders head surface is. The combustion side of these engines should be sooty and dry. This indicates that the failure was initiated by a combustion side problem.
 

adf5565

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I was wondering about that valve mark as well. There aren't any lock washers I'm aware of on the motor or turbo, especially ones that would have the potential from getting inside. On piston #7 there is a section on the lower left that seems to me “missing” the soot with some red color which looks odd. By combustion side problem does that include head gasket? Or more like piston/cylinder/injection problem?

Moving over to the passenger side of the block and head (pics below), I have a few valve impact marks in pistons 4 and 6. I’m assuming either the crank bent or something else bent to cause the valves to start opening when the piston was TDC. And strangely a little of the mysterious center valve ring imprinted on the piston too. Along with a red ring on pistons 4 and 8 around the intake valves. Not sure what that is. Also weird is 6 looks cleaner than the rest, with red residue on the head.

IP is a rebuilt 4911 pump that is supposed to be set to standard fueling. In the moments before failure my autometer EGT gauge was <1000. Even when pushing it hard I’ve never had it over 1050. Probe is tapped into the exhaust manifold before the turbo.

I'll lead you know about the heads. I haven't decided yet what I want to do.

IMG_2509.jpegIMG_2510.jpeg
 
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gringeltaube

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The combustion side of these engines should be sooty and dry.
Agreed, even if 3500 miles is not enough to consider this a good used motor...

Reading post 1 again, it doesn't seem as if there was any sign of loss of power or cylinder(s) misfiring, shortly before the disaster.
How could a faulty injector cause this much havoc in just seconds?
 

adf5565

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Agreed, even if 3500 miles is not enough to consider this a good used motor...

Reading post 1 again, it doesn't seem as if there was any sign of loss power or cylinder(s) misfiring, shortly before the disaster.
How could a faulty injector cause this much havoc in just seconds?
Yeah definitely no noticeable change in power, only that slight noise. When the motor/injectors were new I believe I briefly had a stuck injector (or potentially a last bubble of air working itself out) and that was much more noticeable sounding.
 
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