1,000 mile new engine disaster

[Garbage_Mechan]

So the 86 in my sig finally got tired with 450,000 miles plus. This was back in 2013.
Did a total top notch rebuild including Mahle pistons, mild port job, head studs and more. Clearances and protrusion set, much attention to detail. So then everything in my work world went upside down before I really had it it broken in, maybe 1k miles on it. With everything changed and me working in Montana I decided to give it to my son, he was getting in need of a reliable vehicle. He wasn't quite ready to pay for insurance and regs yet, so I gave him strict orders to start it up no less the once every two weeks and let get up to operating temp. So I get a call from my wife (while I'm 1,200 miles away in MT). Rather agitated. "Your son's truck just blew up" What do you mean it blew up? "He started it and it went BANG and all the coolant shot out all at once." Trying to visualize........ "Oh an there's parts on the ground under the truck" Like what? "A freeze plug and a piece of gasket" Oh that couldn't of come from the 86, must be old. "No, brand new, I'll send a picture" Studying picture.............mmmmn that does look like a new freeze plug and a piece of head gasket. Ok, I'll check it out next time I'm home...

 

[Garbage_Mechan]

So a few weeks later I get home and we check it out....yep the head gasket is blown out and a piece missing, and soft plugs blown out. Pulled it, pulled heads. Only visible damage is a pretty serious rust pit in the middle of the rig travel on cylinder 8, same one the head gasket was blown out on. Thinking and looking a little longer decided to check the piston protrusion since it was set very close to the same on every cylinder. Sure enough # 8 was down .020 below the rest, indicating a bent rod.

 

[Garbage_Mechan]

So now I'm pretty pissed, not because it happened, but because I have taken nearly perfect care of this engine for the past 10 years and 350,000+ miles. Maintenance and repairs on time, never let it overheat, always warmed up etc.

 

[Garbage_Mechan]

So here is what I believe happened. Looking things over, the cowl seal was poor. The air cleaner lid showed signs of standing water. Where the truck was parked #8 was the lowest point. The cylinder wall rusted (coolant doesn't allow rust) So it is pretty clear rain water was in cylinder 8 when it was started. It must have been the perfect amount to allow the piston to come almost to TDC, but then generate incredible pressure to blow the head gasket completely out on the ground as well as blowing out soft plugs and bending the rod. In all my 39 years of diesel mechanics I've never seen this happen. Hydrolocks and bent rods yes, but never head gasket blown out on the ground. With head studs no less.

 

[Garbage_Mechan]

So what should the repair plan be? I want to go back to 100% built engine with no questionable repairs. So here is what I'm thinking:
Replace #8 rod, replace #8 piston (can see no damage but after that much intense pressure SOMETHING must have happened to it) Magnaflux and surface check the left head including valve seats, valves etc, sleeve #8 cylinder due to both the rust pit and the fact that much pressure MUST have balooned or cracked it. New rings, gaskets. Some work will have to be done to be sure piston clearances match and projection matches. Need to find a known good # 8 rod from a trustworthy source and have it checked and rebushed. Hopefully Mahle will sell a single matching .020 over lowered compression height piston.
Anybody see a flaw in my plan?

 

[Garbage_Mechan]

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[laserjock]

All I've got is wow.

My uneducated opinion would be to check everything in the rotating assembly. If it had enough force to do that it could have twisted anything.

 

[abepratt]

I would definitely check the crank. I wouldn't be surprised to find it bent...

Sent from my HTC6535LVW using Tapatalk

 

[franklin2]

Pretty normal when a cylinder is hydrolocked. But most of the time it doesn't blow out the soft plugs and the headgasket. It usually just bends the rod, and the engine still runs, it just has a slight miss to it from that cylinder not firing properly. It happens to gas engines also.

 

[Garbage_Mechan]

One good thing that came out of this: I learned that my machine shop, while well versed in many things, didn't know the proper way to install IDI soft plugs. So likely this saved it from another disaster when one of the soft plugs just fell out someday in the future. (happen to anybody else on here?)

 

[laserjock]

Gary icanfixall had it happen I believe.

 

[snicklas]

Gary had it happen twice on the same rebuild. One happened at like 500 miles, and he caught that one.

The second one happened at about 5000 miles, he was pulling the Grapevine when the plug blew..... he caught it when the lifters were ticking and the OIL TEMP was over 300 degrees....... it didn't survive that one........

Oh, and the "best" part of this story..... the machine shop told him not our problem..... sucks to be you.......

 

[FORDF250HDXLT]

http://www.ebay.com/itm/Rubber-Hood...rd-Bronco-F-Series-Pickup-Truck-/370873054028

 

[typ4]

Man that sucks. Get that crank magged for sure. Maybe even x rayed. I bet the gasket failed to the water port and jacked the plugs out. And coolant will rust, just not as quick as water.
One of my shop guys for what ever reason poured coolant onto a random bucket of oil, problem is the bucket had planetary gears in it that are NLA. Now they are rusty.