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Discussion Starter #1
Okay, the truck always made a few strange noises after shutdown, but this is new and annoying.
Here's the scenario: Truck is warm and no CEL. A few seconds after shutdown, I hear all the normal(?) noises and then after a few seconds of silence, a noise that sounds like a vacume pump running starts and continues for about 20 to 30 seconds. Cycling the key, but not starting the motor will cause the noise to happen again and again on each key on/off cycle.
The noise seems to be comming from the top front of the motor.
Could this be fuel pressure bleeding off? Is there a check valve that is maybe not doing it's job??

Stumped

jammer
 

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I dont know how it is on a 6.7 but on my 6.4 i would hear a pump sounds like a fish tank pump, turns out i had a vacum leak, the pump is located by the master brake cylinder, on the fuze box/power box dont know where it is on the 6.7
 

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Discussion Starter #3
I think the vacume pump on the 6.7s is driven by the accessory belt. This sounds similar, but is definately comming from the top front of the motor. Haven't been able to isolate the exact location, but is in the neighborhood of the HPOP or fuel filter.

jammer :cool:
 

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It might also be the DEF pump, not sure where that is located, probably not in the engine bay, but noise could travel. The pump sucks all of the DEF out of the DEF line after shut off I believe.
 

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Discussion Starter #5
DEF pump is on the DEF tank, no DEF lines are under the hood, all are under the chassis mid truck.

jammer :cool:
 

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Discussion Starter #6
Here's the noise with the hood closed. With the hood open, noise is most definately from top front of motor.


jammer :cool:
 

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Discussion Starter #7
Here's the noise with the hood closed. With the hood open, noise is most definately from top front of motor.

jammer :cool:
Although the video is from outside the truck, when I open the hood, the noise is from right on top of the motor at the front, more on the left side than the right.

jammer :cool:
 

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I think the vacume pump on the 6.7s is driven by the accessory belt. This sounds similar, but is definately comming from the top front of the motor. Haven't been able to isolate the exact location, but is in the neighborhood of the HPOP or fuel filter.

jammer :cool:
Can't be by the HPOP,, as we don't have one of those on the 6.7....:nono:

I agree with Ron,, why in the world have you not taken it to the dealer? I certainly would,, as mine does NOT do that,, I do hear the turbo spooling down after shut down though! (Normal on all the turbo diesels....LOL)
 

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Discussion Starter #10
My bad, meant the HPFP.

Okay, here's an update.

The motorboat definately starts immediatly following the EGR closing noise.
Crawled into the hood yesterday, put my ear as close as possible, still cannont hear where the damn noise is originating from. Felt around for vibrations, nothing. Seems like the intake plumbing is amplifying/transmitting the noise all over the left side of the motor. Hmmmmm
Going to the dealer on Mon. If only I trusted these guys........


jammer
 

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Discussion Starter #11
Okay, new information; when the noise starts, a tap of the brake pedal silences the noise! Vacuum issue? Booster issue? Getting close to a solution.


jammer :cool:
 

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Vacuum boost brakes or hydro boost? ABS pump maybe.
 

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Discussion Starter #13
Definately a vacuum issue. Once I discovered the association with the brake booster (vacuum boost on 250s), I can stop the noise by unplugging any of the vacuum lines that I can find.

jammer
 

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Discussion Starter #14
Anyone out there have a diagram of the vacuum system for F250's?

I'm thinking there is a check valve on the vacuum line right at the vacuum pump. That would make sense and would keep the pumped down vacuum from bleeding off.

Seems that that check valve (if it exists) is having a conversation with the whole system. That conversation manifests itself as my 'motorboat noise' and is initiated by the EGR closing event which causes a 'burp' in the entire system.

Ahh, the joys of a new series of truck!

I really wish I could have a conversation with a Ford engineer that worked on the vacuum system on these trucks!

jammer :cool:
 

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Anyone out there have a diagram of the vacuum system for F250's?

I'm thinking there is a check valve on the vacuum line right at the vacuum pump. That would make sense and would keep the pumped down vacuum from bleeding off.

Seems that that check valve (if it exists) is having a conversation with the whole system. That conversation manifests itself as my 'motorboat noise' and is initiated by the EGR closing event which causes a 'burp' in the entire system.

Ahh, the joys of a new series of truck!

I really wish I could have a conversation with a Ford engineer that worked on the vacuum system on these trucks!

jammer :cool:
I can definitely see why you’d want to pinpoint where a noise like that is coming from. If you would like my assistance with the concern, send me a PM, and I will re-open and escalate a case for you!

Cory
 

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Discussion Starter #20
Should have some answers on 4-21. Hope the dealer guys are smart enough to figure this thing out.

jammer :cool:
 
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