Can a Hung injector Break a Crank?
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Can a Hung injector Break a Crank? Ok, so as the title says, can a hung injection cause a crack to break? This isn't specific to the LS, it's more of a general engine question.
The reason is ask is at work, we had a customer that broke their crank on a motor (Huge Diesel Motor in a Mining machine) and they believe it is due to a bad injector that hung open.
The more I think about it, the less I think this is possible. The only way I could see this happening is if the injector hung, caused the engine to overrev for an extended period and break the crank. In this particular mining truck that would mean someone would a have a serious wreck with a runaway truck. That is not what happened.
So my question is to you savvy engine guys out there is this possible? Have you seen it? And what causes the crank failure in the end?
The reason is ask is at work, we had a customer that broke their crank on a motor (Huge Diesel Motor in a Mining machine) and they believe it is due to a bad injector that hung open.
The more I think about it, the less I think this is possible. The only way I could see this happening is if the injector hung, caused the engine to overrev for an extended period and break the crank. In this particular mining truck that would mean someone would a have a serious wreck with a runaway truck. That is not what happened.
So my question is to you savvy engine guys out there is this possible? Have you seen it? And what causes the crank failure in the end?
Did it break running or starting?
I don't really know anything about diesels but depending how much momentum was built up in cranking the engine before a cylinder full of fuel hit compression is suppose it is plausible.
For it to break running I think you are right about how that would have to happen with an overev. I just don't think there would be time to fill a running cylinder with enough fuel to hydrolock with a stuck injector.
You said a runaway engine would have meant a runaway truck, no neutral, low gear etc. that would allow control to be retained while an engine overrevved?
Could have been a manufacturing flaw in the crank that survived till something else went slightly wrong??
I don't really know anything about diesels but depending how much momentum was built up in cranking the engine before a cylinder full of fuel hit compression is suppose it is plausible.
For it to break running I think you are right about how that would have to happen with an overev. I just don't think there would be time to fill a running cylinder with enough fuel to hydrolock with a stuck injector.
You said a runaway engine would have meant a runaway truck, no neutral, low gear etc. that would allow control to be retained while an engine overrevved?
Could have been a manufacturing flaw in the crank that survived till something else went slightly wrong??
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Staging Lane
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From: Finleyville
Yes I would believe that the crank broke because
the injector stuck open and the crank broke upon startup, But for this to happen while runnin is next to impossible,especially if it is a mechanical injection system common rail system it might be possible but very unlikely. If this happened while the engine was running and it is a mechanical injection system I would believe its a timing issue with the injection pump. Pre detonation is dangerous on a gas motor but it's pretty much fatal to a diesel if the injector fires before TDC. Especially if the charger was cranking and the driver was in the throttle hard. Imagine the piston half way or almost all the way up on its compression stroke and it gets smashed dead on with a sledge hammer.
the injector stuck open and the crank broke upon startup, But for this to happen while runnin is next to impossible,especially if it is a mechanical injection system common rail system it might be possible but very unlikely. If this happened while the engine was running and it is a mechanical injection system I would believe its a timing issue with the injection pump. Pre detonation is dangerous on a gas motor but it's pretty much fatal to a diesel if the injector fires before TDC. Especially if the charger was cranking and the driver was in the throttle hard. Imagine the piston half way or almost all the way up on its compression stroke and it gets smashed dead on with a sledge hammer.
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Yes I would believe that the crank broke because
the injector stuck open and the crank broke upon startup, But for this to happen while runnin is next to impossible,especially if it is a mechanical injection system common rail system it might be possible but very unlikely. If this happened while the engine was running and it is a mechanical injection system I would believe its a timing issue with the injection pump. Pre detonation is dangerous on a gas motor but it's pretty much fatal to a diesel if the injector fires before TDC. Especially if the charger was cranking and the driver was in the throttle hard. Imagine the piston half way or almost all the way up on its compression stroke and it gets smashed dead on with a sledge hammer.
the injector stuck open and the crank broke upon startup, But for this to happen while runnin is next to impossible,especially if it is a mechanical injection system common rail system it might be possible but very unlikely. If this happened while the engine was running and it is a mechanical injection system I would believe its a timing issue with the injection pump. Pre detonation is dangerous on a gas motor but it's pretty much fatal to a diesel if the injector fires before TDC. Especially if the charger was cranking and the driver was in the throttle hard. Imagine the piston half way or almost all the way up on its compression stroke and it gets smashed dead on with a sledge hammer.
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It's a mechanical injection system, and recently, both fuel pumps were replaced, but the injectors werent checked. We believe it happened while running, but we aren't sure. We should be disassembling the engine next week.
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Yes, neutral could be used, but these trucks carry between 120-150 tons of material at a time, a retarder is used ALL the time along with the brakes. Pulling it into a low gear would end up with a bag of parts for a Trans and a runaway truck.
Did it break running or starting?
I don't really know anything about diesels but depending how much momentum was built up in cranking the engine before a cylinder full of fuel hit compression is suppose it is plausible.
For it to break running I think you are right about how that would have to happen with an overev. I just don't think there would be time to fill a running cylinder with enough fuel to hydrolock with a stuck injector.
You said a runaway engine would have meant a runaway truck, no neutral, low gear etc. that would allow control to be retained while an engine overrevved?
Could have been a manufacturing flaw in the crank that survived till something else went slightly wrong??
I don't really know anything about diesels but depending how much momentum was built up in cranking the engine before a cylinder full of fuel hit compression is suppose it is plausible.
For it to break running I think you are right about how that would have to happen with an overev. I just don't think there would be time to fill a running cylinder with enough fuel to hydrolock with a stuck injector.
You said a runaway engine would have meant a runaway truck, no neutral, low gear etc. that would allow control to be retained while an engine overrevved?
Could have been a manufacturing flaw in the crank that survived till something else went slightly wrong??
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It is obvious we MUST find out if this thing was running during the event, or if it was upon startup. We think it was running, but again, I can't confirm it. As for the driver, there is basically WOT and idle.
Yes I would believe that the crank broke because
the injector stuck open and the crank broke upon startup, But for this to happen while runnin is next to impossible,especially if it is a mechanical injection system common rail system it might be possible but very unlikely. If this happened while the engine was running and it is a mechanical injection system I would believe its a timing issue with the injection pump. Pre detonation is dangerous on a gas motor but it's pretty much fatal to a diesel if the injector fires before TDC. Especially if the charger was cranking and the driver was in the throttle hard. Imagine the piston half way or almost all the way up on its compression stroke and it gets smashed dead on with a sledge hammer.
the injector stuck open and the crank broke upon startup, But for this to happen while runnin is next to impossible,especially if it is a mechanical injection system common rail system it might be possible but very unlikely. If this happened while the engine was running and it is a mechanical injection system I would believe its a timing issue with the injection pump. Pre detonation is dangerous on a gas motor but it's pretty much fatal to a diesel if the injector fires before TDC. Especially if the charger was cranking and the driver was in the throttle hard. Imagine the piston half way or almost all the way up on its compression stroke and it gets smashed dead on with a sledge hammer.
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Staging Lane
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From: Finleyville
I was thinking more about this the other day. I'm not 100%sure behind this theory but if the injector failed while the de compression brake was turned on this might cause enough of an imbalance across the crank that it could have caused such high harmonic vibrations the crank gave out. Just a thought.
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I was thinking more about this the other day. I'm not 100%sure behind this theory but if the injector failed while the de compression brake was turned on this might cause enough of an imbalance across the crank that it could have caused such high harmonic vibrations the crank gave out. Just a thought.
Diesel engine runaway can happen easily when it finds a new source of
fuel. A leaky turbo or blower seal that blows out will allow the motor to
burn engine oil feed to it under pressure. The govenor will not save it
Truck drivers don't tell on themselves
fuel. A leaky turbo or blower seal that blows out will allow the motor to
burn engine oil feed to it under pressure. The govenor will not save it
Truck drivers don't tell on themselves
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Yes, we have seen it happen, to the point of burning a machine to the ground! I will say again though, that is not what happened here. Nothing burned up, and there was no incensed with the truck.
