Severe 6.7 knock.

Bustedknuckles · Jul 3, 2013

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

jimdawg185 · Jul 3, 2013

Ouch, yeah.

TXGLASSMAN · Jul 3, 2013

Sounds like a rod to me

01PSD · Jul 3, 2013

Another C&C bites the dust.

Dzchey21 · Jul 3, 2013

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

01PSD · Jul 3, 2013

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

I was going to say the same. Very common problem

12stroker · Jul 3, 2013

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

Bustedknuckles · Jul 3, 2013

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...

Bustedknuckles · Jul 8, 2013

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

SEABEE08FX4 · Jul 8, 2013

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

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.

Bustedknuckles · Jul 8, 2013

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.

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.

Dzchey21 · Jul 8, 2013

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

Dzchey21 · Jul 8, 2013

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

SEABEE08FX4 · Jul 8, 2013

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.

Bustedknuckles · Jul 17, 2013

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.