Update: Blew the motor

[Brutis]

Well, my problems just got bigger and more complicated - I blew the motor about 20 minutes ago. I went to start it up this afternoon to go tow my wife's car home (bad fuel pump) and the motor ground to a halt and rattled horribly in the process. Bent or broken rods?

I noticed a tick a couple days ago (sounded like it was coming from the front - I was thinking bearing of one kind or another), but never expected this to happen.

What should I do first? I've never rebuilt a diesel.

 

[fx4wannabe]

The first step I would take if you are going to do the work is get the motor pulled and then tear it down so you can see what you got. Then if the block is still good go from there.

 

[david85]

If you want to try and turn it over gently by hand, you could use a 15/16" socket, ideally with a 1/2" drive breaker bar and a 2" extention.

 

[Brutis]

I'll be looking into it more this afternoon. Any ideas on what would cause it to blow on start up like that? Could the tick have been from a bad water pump and I hydro locked when I started it up today?

 

[Brutis]

Does it matter which direction I rotate the crank?

 

[david85]

Short of some sort of fuel starvation issue, my guess would be a spun bearing.

Startup is always the hardest on bearings because oil is not yet pressurised in the bearings. Any defect that is already there is likely to happen when first starting up.

At least it didn't happen out on the road somewhere.

 

[TwoTone IDI]

i dont know how a bad pump would let water into the combustion chamber, someone please educate me if its possible

you could have been dealing with a bad head gasket, mine was bad and slowly leaking water and i never knew it. since i only drove it once a week it let enough in... i bent my #7 connecting rod with the starter. after that it would run but it made a very bad knocking sound.

first thing id do is take a look at your oil. milky means you know what.

i also wouldnt put it past a very bad injector to fill a cylinder up with diesel. unlikely id say but possible... just cause youd need fuel pressure to drip enough in there and youre not gonna have much when the truck is sitting still.

check your oil first off, that will tell you a LOT. if you see babbitt or milkyness you know youre going all the way in.

never hurts to pull a valve cover and see if you gotta bent pushrod, broken spring, or something else stupid. those things have sounds all to themselves tho, and in my opinion always sound "smaller"... more of a tap than a knock.

i JUST rebuilt my first motor ever and it happened to be a 7.3. its not rocket surgery especially if youre just putting stock parts back in. this site has a RIDICULOUS amount of support for DIYers like you and me. i owe all my success to this place.

 

[Brutis]

The bearing makes sense - I was attempting to prevent dry start ups by running Amsoil and Lucas synthetic oil stabilizer, but I think the truck has over 272,000 miles on all original parts.

I could have had a fuel starvation issue with the problems I posted last night - how would that blow the motor though?

 

[towcat]

i also wouldnt put it past a very bad injector to fill a cylinder up with diesel. unlikely id say but possible... just cause youd need fuel pressure to drip enough in there and youre not gonna have much when the truck is sitting still.

never say never.
i've personally witnessed a motor hydrolock due to a injector holding open. three other members here at OB witnessed the fuel geyser shoot out of the GP hole when we pulled the GP and barred the motor over.

 

[franklin2]

How do you know the motor is "blown" or "blown up" and needs a complete rebuild? Will the starter turn it over? I didn't see anything in the description in your first post that the motor is terminal, unless you left something out or I missed it.

 

[GOOSE]

Sorry to hear your dilemma, Scotty. If you remember, I'm going through this same thing, and my engine ran untill I pulled it into the shop for extraction. A 2" crack between the water jacket and cyllinder. Mark7.3IDI has a very nice 7.3 for sale, very reasonable also. I have PM'ed him about it and is under consideration for me to buy. If its close enough for you and you want it, its there for the taking. He said 150,000mi, complete ready to drop in.

Good luck with your endeavour, keep us posted.

 

[Brutis]

O.K. The oil looks OK. My dad agreed. I can turn the motor over with a socket and breaker bar. Pretty easy to turn actually. It doesn't seem to get harder and easier at different points. It feels about the same all the way around. Yes, the starter will turn it over. The first couple of times, it ground to a halt and rattled really bad. The 3rd time, after my dad came the motor did fire up, it just clatters horribly - it sounds hollow - that is how my dad and I can best describe it.

Also, I do have a spare engine, but I have no idea of its condition.

 

[fx4wannabe]

Well if it starts and runs that is a good sign. A video posted on here might help with trouble shooting if you have a way of making one.

 

[tonkadoctor]

This won't cost you nothing but time to check and may save you from replacing the whole engine.

Pull your valve covers and check for broken rockers, pushrods, valve springs, dropped valves etc. These engines are known for losing lifters which in turn takes out the push rods and possibly rockers.

 

[Brutis]

I'll try to get a video first thing tomorrow, and I'll pull the valve covers off after that and see whats going on in there. Thanks for the advice. This is a first for me, and the truck had always run so well - with 440psi in all 8 cylinders when I tested in March, right before I added the turbo.

Could my timing have slipped really bad?