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-   1999 - 2003 7.3L Power Stroke Diesel (https://www.ford-trucks.com/forums/forum31/)
-   -   Let’s play what’s that sound! (https://www.ford-trucks.com/forums/1565439-let-s-play-what-s-that-sound.html)

MD_7.three 12-12-2018 04:59 PM

Let’s play what’s that sound!
 
Alright...I’m trying to figure out what’s causing this sound. It’s already been to a transmission shop and their analysis says it’s not the transmission. Their theory is it’s harmonic vibration and stops because the engine shifts on its mounts when it goes into reverse...perhaps an exhaust leak they said.

it started out of the blue last Friday, and when driving slowly in reverse it will “come back”

no DTCs. Buzz test and CCT were normal per forscan. No loss of power. No smoke.


ZachinCO 12-12-2018 05:10 PM

Says video unavailable?

Sous 12-12-2018 05:37 PM

I get the same response as Zach when clicking on the video link. Make sure you didn't accidentally list the video as private or unlisted.

EDIT: I can hear the difference in the sound, but I am sorry that I cannot help in any way. Does the engine run fine and the transmission act as it should other than the strange noise?

MD_7.three 12-12-2018 05:45 PM

Sorry. YouTube rookie. Forgot to hit publish!

MD_7.three 12-12-2018 06:16 PM


Originally Posted by Sous (Post 18357786)
I get the same response as Zach when clicking on the video link. Make sure you didn't accidentally list the video as private or unlisted.

EDIT: I can hear the difference in the sound, but I am sorry that I cannot help in any way. Does the engine run fine and the transmission act as it should other than the strange noise?


It seems to be running as it should...its bone stock except a 6637...shifts are firm....had the torque converter replaced (upgraded to triple disc billet low stall and got rid of my noisy 99 converter, trans inspected then as well) about 1300 miles or so before it started which is why it went straight back to the transmission shop...

I literally parked at my sons school to pick him up last Friday, and when I walked out immediately noticed the difference...I haven't had enough miles on it to see if there's a noticeable drop in fuel economy but we've also hit winter weather here so with the extra idling it will be much harder to track for certain...

I should add I do get the cylinder 8 misfire from the CCT, but I've read without an FRx that's normal...could this be cackle? Perhaps they're onto something with an exhaust leak? I make normal boost for stock...and all the normal data monitors in forscan are unchanged from before/after the noise started...

It has 15w-40 conventional in it now...I'm switching to T6 5w-40 this weekend and attacking the glow plugs, so I'll be under the valve cover...new UVCH's going in with all new motorcraft gp's and a new motorcraft gp relay as well.

ZachinCO 12-12-2018 08:42 PM

That’s an odd one. Have someone lay underneath and see if they notice anything.

z31freakify 12-12-2018 08:51 PM

Any chance your EBPV is closing?

dmd 12-12-2018 09:07 PM

With the EBPV is there a noted hissing from the exhaust when it does this?

z31freakify 12-12-2018 09:13 PM

Yes an EBPV will will emit a loud hissing almost jet like sound, it might be partially be closing causing the intake tone to change sound.

MD_7.three 12-13-2018 02:16 AM

I’ve been under it with it on the lift going over it with the transmission guy...

i will takw take a look at the EBPS values tomorrow, but that is one I already have on my monitor and I don’t recall anything abnormal in the readings...maybe if it were just barely stuck...but on a cold start the ebpv still operates...it should be a fairly cold start in a few hours so I’ll pay extra attention...

why would that “go away” shifting to reverse though?

MD_7.three 12-13-2018 08:14 AM

EBPV didn’t activate this AM as it was warmer than expected and I was plugged in...

KOEO - MAP 14.8, EBP 14.7, Baro 14.7....KOER MAP 14.8-15.0 EBP 15.1-15.7 over about a 2 minute hot idle. Average delta .2-.3 over MAP...same behavior in terms of noise disappears in reverse idle, comes back in park/N/drive idle.

Only 109k on the odometer.

Walleye Hunter 12-13-2018 08:34 AM

My hearing must be more degraded than I was aware of, I can't hear the sound that you guys are hearing

PrescottIce 12-13-2018 09:25 AM

Recorded audio is hard to diagnose through - but it sounds like something is touching the firewall or floorpan when in P/N/D and transmitting engine noise to the cab.

slowsure 12-13-2018 10:09 AM

This is a WAG but, check your power steering fluid level??? Applying brakes when going to reverse changing pressure to steering pump????

BillyBob69 12-13-2018 10:41 AM

Since you are going to have the valve covers off, re-torque the injector hold downs and the rockers. Could be contributing.


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