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No compression in number 5 cylinder 6.7 cumins

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n6454g

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2017 dually with 125000. Always do my oil changes and fuel filter changes at less than manufacturer recommended. Running just fine until my wife hit the throttle to speed up and bad knock started. Dealer telling me no compression in #5 cylinder and need a new engine. Am I truly screwed or can it just be repaired/ rebuilt? What could have caused this I’m stumped. Any techs out there provide some insight?
 
I’d want an explanation from the dealer why it needs a new engine before pulling the trigger. Short of a hole in the side of the block things can typically be rebuilt, but a dealer may shy away from that where a independent diesel shop would not. As far as cause something in the valvetrain could of let loose, a injector could of let go and put a hole in the piston, but without further diagnosis other than “no compression” it’s a guessing game.
 
I don’t know what your replacement cost is, but I imagine a repair would be considerably less. Also it would be pure speculation until a actual diagnosis is disclosed.
 
True. I know there isn’t a hole in the block or anything because I don’t have any fluid leaks at all
 
They quoted be almost 30k. New engine 25k roughly than labor. Engine would have the 100k warranty on it
 
n6454g said:
They quoted be almost 30k. New engine 25k roughly than labor. Engine would have the 100k warranty on it
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Yowser that’s a big bill. A short block would be much less than that, must be the whole motor with accessories?I’d try a independent shop. Where are you located maybe someone local can recommend one.
 
I'm with @flan above, find a reputable diesel shop or 2 and get a couple of more opinions/estimates. $30K seems like a big number to me and it could be something fixable in-frame rather than yanking the whole motor.
 
Yeah. One of the reasons for the expense is they said to replace the motor they would have to pull the cab off. I’m located in Belfast maine area
 
I’d find a new shop, you don’t have to pull the cab off.

You should be able to get a rebuild for 1/2 that price, but call around. Try to find a local diesel
club and see who they recommend taking it to.
 
Can anyone explain this one also? With all the friggin sensors on these trucks, why didn’t I even get a check engine light on after it happened? No codes not lights…NOTHING? Why?
 
n6454g said:
Can anyone explain this one also? With all the friggin sensors on these trucks, why didn’t I even get a check engine light on after it happened? No codes not lights…NOTHING? Why?
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Depends on why it failed. Lots of things don’t have sensors. Most the sensors are for emissions reasons, not general engine operation.

Wrist pin, injector stuck open, rings, valve failure, etc.
 
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Great White North Eh said:
Pull the cab off??? Do they think they are a Ferd dealer? :eek:
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yeah that’s what they are saying. Unfortunately I’m ignorant to these things. I’m not a mechanic and know some basic stuff but I surly can’t work on engines. That is my down fall now in this situation. That’s why I’m reaching out to people who may know better then me
 
I concur with the other opinions take it to an independent shop . You are out of warranty so find a reputable shop . They can ascertain if the cylinder is repairable .They will pull the head to look at the piston and drop the pan to check out the crank and bearings . Make sure they work on Diesels are ASE certified and know Cummins engines . You can check them out on line . Not Rocket science just labor intensive = $$$
 
So dealer called today with the actual estimate..29k. Ask them about rebuild and he states that his senior master diesel tech said the knock was in the bottom of the block and that in is opinion it would 1. Cost more to rebuild if they even tried and 2. With it being in the bottom of the block and zero compression in #5 cylinder it probably can’t be rebuilt. I know the dealers are in it for making money and not the interest of us but feeling screwed either way. Service guys even stayed something about a pin could have come
Loose which I know is a common problem with this years engine but they don’t want to do the investigation
 
Can’t say I’ve seen many 2017 engines with no compression or rod knock. I’m skeptical by nature and this story has me keyed up.
 
flan said:
Can’t say I’ve seen many 2017 engines with no compression or rod knock. I’m skeptical by nature and this story has me keyed up.
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I'm with you @flan. If it looks like poop and smells like poop we don't need to pop a piece in our mouth to see if it tastes like poop. Start knocking on some local reputable diesel mechanic's doors.
 
CaptainMike said:
I'm with you @flan. If it looks like poop and smells like poop we don't need to pop a piece in our mouth to see if it tastes like poop. Start knocking on some local reputable diesel mechanic's doors.
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Yeah. I’m trying to get hold of some diesel places today and see if they will take a look. What is a rod? Is it what holds the piston on the crank shaft?
 
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