Severe 6.7 knock.

Got a 6.7 cab and chassis truck with 33k in the shop. I did a dpf delete with no added power a couple months ago and it got towed in today for this knock. Any ideas? Sounds like rod knock to me....
https://www.youtube.com/watch?v=Cq6qUkJTZBQ&feature=youtube_gdata_player

Ouch, yeah.

Sounds like a rod to me

Another C&C bites the dust.

could have dropped a valve, they are famous for that, and that sounds to me like full piston contact, let us know what you find... thats a bummer

Dzchey21 said:

could have dropped a valve, they are famous for that, and that sounds to me like full piston contact, let us know what you find... thats a bummer

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I was going to say the same. Very common problem

ohhh man that hurts me to hear this.... I have been waiting for our f550 to drop a valve or blow the turbo

Now that y'all mention it I would agree its a valve, it doesn't have the "rattle" of a rod knock, its solid and rhythmic. We are trying to find a DPF asap so the owner can take it to ford. The one we took off got stolen and there aren't many deleted 6.7's around...

So what exactly happens when they drop valves, does the valve itself break or does the seat fall out?

Bustedknuckles said:

So what exactly happens when they drop valves, does the valve itself break or does the seat fall out?

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Pretty much shatters, no two really look the same when it happens. Some crack and some literally shatter into pieces. I agree on the valve though, if its a 2011 I'd be 110% certain of it.

SEABEE08FX4 said:

Pretty much shatters, no two really look the same when it happens. Some crack and some literally shatter into pieces. I agree on the valve though, if its a 2011 I'd be 110% certain of it.

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Thanks. As soon as I get this 6.0 out I'm going to disable the fuel system, amp clamp the starter wire and crank it to verify it before I send it to ford.

My uncles truck is doing the same thing, is not even tuned, but it only does it going down the road, ford is going to replace the left cylinder head

It could be a bent valve too, but usually the head drops off of the valve

If its really bad your gonna see something like this.





If the owner of the truck is lucky you caught it early and it is only cracked at this point, thats to say if it even ends up being a valve issue.



These are not my pictures by the way, just examples of what happens from bad to really bad.

So DPF i found for it didn't fit the truck since it was a cab and chassis so we ended up talking to the local dealership and they said bring it in as is, they didn't care! :shocked: According the their main 6.7 tech the valve issue is caused by bad glow plugs overheating and cracking the valve and it is very common on the early production 6.7s. The customer got it towed to them and as far as i know ford is replacing the engine free.

Ford has already admitted the early run of the motors had valves that didn't go through the hardening process and in turn were defective.