What could cause this?

B

bambam-x

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Oct 1, 2006
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Truck has been running great. Shut it down and parked it for a few weeks, when I started the truck and it is bucking like mad had vibration and a loud knocking sound. Won’t restart in fear that something let go in the bottom end.

Truck has 180k miles and all the pertinent parts have fallen off ?

Any thoughts?


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Batteries? I’m certainly no CR expert, but I know low battery voltage does strange things.
 
Hmm never thought that could cause this. Will check first thing.


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With a weak battery it can cause the injectors to not fire correctly.
 
if it has already thrown a brg or rod it isnt gonna get better.might as well let it idle and see what happens
 
dieselbeef said:
if it has already thrown a brg or rod it isnt gonna get better.might as well let it idle and see what happens
Click to expand...


Yea but with the cost of core charges would hate to go even further and punch the block or something else.


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A loose flexplate sounds like a rod knocking at idle, but mostly goes away off idle. Had them back out on my 98 12v years ago, thought it was hosed...semi-quick fix.

Chris
 
Signature600 said:
A loose flexplate sounds like a rod knocking at idle, but mostly goes away off idle. Had them back out on my 98 12v years ago, thought it was hosed...semi-quick fix.

Chris
Click to expand...


I could see the sound from this but would it cause the horrible running engine shaking the whole truck?


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Checked the batteries, both sitting at 11.6v. Put the truck on the charger to see if that makes a diff. If not the. I’ll check fuel filter.


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With all the electronics on newer trucks (all brands) they like to see a full 12 volts. We have run into issues on our fleet of Ford 6.7 Powerstrokes at work because of low battery voltage. Swap in good batteries and the problems go away.
 
Did you have any warning lightes on the dash?

Was there a red lightning bolt looking warning on the dash by chance?

My 08 started bucking, and had terrible fuel knock, and the red lightning bolt warning light was on while this was happening.

It ended up being a bad exhaust back pressure sensor, it was shorted and messing with the 5v single down the line to all the other sensors.
 
jasonc said:
Did you have any warning lightes on the dash?

Was there a red lightning bolt looking warning on the dash by chance?

My 08 started bucking, and had terrible fuel knock, and the red lightning bolt warning light was on while this was happening.

It ended up being a bad exhaust back pressure sensor, it was shorted and messing with the 5v single down the line to all the other sensors.
Click to expand...

I did not notice any warning lights, lightning bolt or CEL. Will check again tonight when I try again with fully charged batteries.

Thanks
 
I would get a look at the valvetrain on that one. Get each hole to tdc and check lash.

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Not a common rail guy but I’d pull the valve cover. Doesn’t sound like injector knock to me
 
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