Dozer died in a cloud of black smoke about 45 minutes after an oil change. She wasn't working hard, just pushing some tree tops at about 1500rpm. At first it seemed like the injector pump as it wasn't getting any fuel to the injector but because of the way she stop I just wanted to look at the top of the engine and see that everything was moving when it cranked. What I found was a broken valve.
1, Is there any reason the injector pump would stop working because of this or is that a whole different problem?
2, What else can I expect to find after something like this.
She had good oil pressure at the time, not sure why this would happen. I've owned it about a month and put between 20 and 30 hrs on what I was told was a rebuilt engine.
Broken valve on 450c dozer
engine smoked
Hi,
What you had was a major engine failure:broken valve is minor compared to what you will find when you pull it down.
My guess based on past rebuilds and buying non-runners is you will find a broken piston connecting rod on cylinder with broken valve.Piston will be damaged as well,liner,etc.
Worse case is damaged crank and damaged head.
Don't think your injection pump is cause or effect since it was running at time of failure.
If the rebuild was recent the rebuilder may honor his work.(probably not).
You can get a running pullout with a little warranty for around $6000.00 from conequipment.com(maybe).
I just picked up a 450C in south central LA for $1600.00. Engine runs great but that's the only good thing I can say about it.I can say dragging a 15,000 pound dozer out of a pine thicket and on to a trailer in 100 degree heat is less than a fun day...
What you had was a major engine failure:broken valve is minor compared to what you will find when you pull it down.
My guess based on past rebuilds and buying non-runners is you will find a broken piston connecting rod on cylinder with broken valve.Piston will be damaged as well,liner,etc.
Worse case is damaged crank and damaged head.
Don't think your injection pump is cause or effect since it was running at time of failure.
If the rebuild was recent the rebuilder may honor his work.(probably not).
You can get a running pullout with a little warranty for around $6000.00 from conequipment.com(maybe).
I just picked up a 450C in south central LA for $1600.00. Engine runs great but that's the only good thing I can say about it.I can say dragging a 15,000 pound dozer out of a pine thicket and on to a trailer in 100 degree heat is less than a fun day...
-
Stan Disbrow
- 350 crawler
- Posts: 2898
- Joined: Fri Jul 15, 2005 3:13 pm
- Location: Raleigh, NC
Hi,
The black smoke is indicative of a high load on the engine causing the governor to open fully. The stopping of the engine is indicative of that load becoming so high that even a fully open fuel feed could not keep it running.
The broken valve is probably due to it hitting the top of the piston. This would load up very high every time it came up the bore. That twists the piston and is where that load comes from. After a short time like this, a relief hole usually forms in the top of the piston. But, before that occurs, the connecting rod bends some. And, sometimes, the crankshaft cracks as well.
So, you have a major problem there. Probably going to need a new cylinder head because the valve probably beat it up as the piston was beating the valve up.
The good news is that it does not sound like it grenaded, meaning the con rod snapped and blew a hole out the side of the block. That is one nice thing about low revving engines. Catastrophic failures tend to not automatically lead to self-disassembly.
This one can probably be rebuilt, but you now have to start down that path....
Stan
The black smoke is indicative of a high load on the engine causing the governor to open fully. The stopping of the engine is indicative of that load becoming so high that even a fully open fuel feed could not keep it running.
The broken valve is probably due to it hitting the top of the piston. This would load up very high every time it came up the bore. That twists the piston and is where that load comes from. After a short time like this, a relief hole usually forms in the top of the piston. But, before that occurs, the connecting rod bends some. And, sometimes, the crankshaft cracks as well.
So, you have a major problem there. Probably going to need a new cylinder head because the valve probably beat it up as the piston was beating the valve up.
The good news is that it does not sound like it grenaded, meaning the con rod snapped and blew a hole out the side of the block. That is one nice thing about low revving engines. Catastrophic failures tend to not automatically lead to self-disassembly.
This one can probably be rebuilt, but you now have to start down that path....
Stan
There's No Such Thing As A Cheap Crawler!
Useta Have: '58 JD 420c 5-roller w/62 inside blade
Useta Have: '78 JD350C w/6310 outside blade
Useta Have: '68 JD350, '51 Terratrac GT-25
Have: 1950 M, 2005 x495, 2008 5103 (now known as 5045D)
Useta Have: '58 JD 420c 5-roller w/62 inside blade
Useta Have: '78 JD350C w/6310 outside blade
Useta Have: '68 JD350, '51 Terratrac GT-25
Have: 1950 M, 2005 x495, 2008 5103 (now known as 5045D)
A hint
Hi Ted,
A little friendly advice on unknown equipment: I buy 10-15 pieces of equipment a year(tractors,loaders,dozers,etc to fix,sell,or keep) NEVER EVER trust any gauge that comes with the unit.
I always evaluate the engines with mechanical type oil pressure and temp gauges.
Takes a little time but getting a true reading on pressures and temps is worth it.
Also it's a verification of the factory installed gauges: if they were accurate and working then put them back in. But the old mechanical types have never let me down and I usually leave those new replacements installed. I'm not worried about "model design correctness"; I want to trust what I see.
A little friendly advice on unknown equipment: I buy 10-15 pieces of equipment a year(tractors,loaders,dozers,etc to fix,sell,or keep) NEVER EVER trust any gauge that comes with the unit.
I always evaluate the engines with mechanical type oil pressure and temp gauges.
Takes a little time but getting a true reading on pressures and temps is worth it.
Also it's a verification of the factory installed gauges: if they were accurate and working then put them back in. But the old mechanical types have never let me down and I usually leave those new replacements installed. I'm not worried about "model design correctness"; I want to trust what I see.
Thanks guys.
It appears that the valve seized in the guide. It,s still sticking out and I can't move it. So there is a chance it did not hit the piston (fingers crossed) but I won't know until I pull the head.
I'm not going to worry about the injector pump until I figure out the rest but do you think the back pressure of a valve not opening could have blown the seals on the pump?
Not sure how to post a picture of the valve stem but if I figure it out I will[/img]
It appears that the valve seized in the guide. It,s still sticking out and I can't move it. So there is a chance it did not hit the piston (fingers crossed) but I won't know until I pull the head.
I'm not going to worry about the injector pump until I figure out the rest but do you think the back pressure of a valve not opening could have blown the seals on the pump?
Not sure how to post a picture of the valve stem but if I figure it out I will[/img]
Ted337, here is a link to the post that shows how to put pictures on this website:
http://www.jdcrawlers.com/messageboard/ ... hotobucket
Most of use www.photobucket.com to host the pictures. Best of luck with your engine fix!
http://www.jdcrawlers.com/messageboard/ ... hotobucket
Most of use www.photobucket.com to host the pictures. Best of luck with your engine fix!
1956 JD420, gearmatic 8a winch, custom 6 way blade and FOPS.
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