DEALER SAYS MILD SPARK KNOCK

[Anthony Palazzolo]

3 Dealerships later and still no fix. Bought the truck in July 2018 802a with 17000 miles. about 2 tanks of gas into it i noticed a mild rattle can sound at WOT at the top end of 3rd and shifting into 4th only.
doesn't matter what grade of gas i put in it but almost always 93 octane. 1st dealer said they could not notice it. 2nd dealer said IWE, replaced check valve gave the truck back and said the rattle was normal.
3rd dealer said that three tech's drove it and all determined mild spark knock. and that it was normal.
One of the Forum members mentioned that changing the spark plugs helped but not 100%. so i had them change mine and the rattle is still there

-No codes at all
-No rattle present an 4A
-No rattle after the truck has been driven and then parked and driven again.
-Rattle present after disconnecting IWE check-valve in essence 4a as IWE engage w/o vacuum
-Since chillier weather has moved in here in Michigan, Rattles worse, more in 3rd and 4th gear. definitely more obvious with cooler temp and cooler engine bay.
-Not sure i agree that its is spark knock at all although it does sound like it.

Ford engineers say that mild spark knock is normal, Frankly im not buying it. I know i'm not the only one experiencing this. Not gonna rag on the truck or ford, I love this thing ,,,,,,but Has anyone found a Fix?

Here's a clip although its hard to hear but its right around the 55-60 mph mark

any help would be appreciated and thanks in advance.

 

[smurfslayer]

-No rattle present an 4A

This is clueful

-Rattle present after disconnecting IWE check-valve in essence 4a as IWE engage w/o vacuum

I’m going to defer to those a little more IWE system knowledgeable on the validity of this as a troubleshooting step.

Here's a clip although its hard to hear but its right around the 55-60 mph mark

Even on full volume, not hearing it through several passes.

Ford engineers say that mild spark knock is normal, Frankly im not buying it.

so, are they hearing and saying it’s pre-ignition, or, are they detecting it with equipment? Most manuals disclaim mild, intermittent spark knock, so modern engines will retard developmentally challenge the ignition timing to account for variables in fuel grade, environmental conditions, etc.

I’m not sure your truck has pre-ignition or a faulty IWE system but the majority of folks who post on here about it find IWE issues, not pre-ignition. It has been generally accepted wisdom here that if you engage 4a and no longer hear the ‘knock’ it’s an IWE issue.

let’s hear what other scientists and engineers from the Wile E. Coyote skul of automotive repair excellence have to say.

 

[jamanrr]

Knock sounds like marbels in a coffee can. I think I picked up a little bit of it but it sounds faint. Have you unplugged the negative battery cable terminal waited 15 minutes or so to reset the fuel maps?

Drive it around and see if it does it again. I had a formula d tuner work on some of my high boost vehicles and he could always tune out fuel grades but lots of factors play into intermediant issues.

 

[isis]

Knock doesn’t get worse in cold weather. It gets better. Red flag.

 

[Antho]

It just sounds like a chirping sound from 5k to shift. My truck does it along with a few others I’ve found online. Only at that shift, no others. Same rpm range as well.

video of mine.

 

[Anthony Palazzolo]

Yes, that is it exactly!!!!!!!!!

Does anybody know what that is?

 

[jamanrr]

Yes, that is it exactly!!!!!!!!!

Does anybody know what that is?

Is there a recirculated blow off valve on the turbos?

 

[Badgertits]

Ummm.....why do you care?

I can barely hear it in either vid, maybe if I listened 5-6x I’d pick
It up

is the truck running poorly? Have your mpg’s gone down? What’s the issue?

 

[GCATX]

I haven't messed with the IWE system on this truck, but I believe that when vacuum is removed from the system, it engages the hubs?
Vacuum drops off when you put a heavy load on the engine, so there may be something going on with the IWE system.

 

[Anthony Palazzolo]

no recirculated blow off valve on the turbos, Truck performs perfectly, Ultimately I may just have to deal with it but its more obvious in the cab of the truck and its just unnerving, not to mention embarrassing on a $73000 truck