Hissing noise when torque converter locks up

[the ponz]

2001 Excursion
7.3l diesel
Stock transmission
56,000 original miles
DIY TYMAR intake
... and yes, the transmission is full of fluid

makes hissing noise only when the torque converter locks up.
it makes no noise when shifting between 1st, 2nd, 3rd, or 4th.

Any thoughts??

thanks

 

[trackspeeder]

Most likely the hissing sound is the turbo with the DIY air intake.

 

[the ponz]

I was thinking today that I might re-install the stock intake and see what it sounds like.

 

[dpantazis]

it might be easier to install the t/c lockup mod, a toggle switch to force the t/c to lockup when you flip the switch.

http://www.superdutydiesel.com/foru...mance/12148-4r100-tc-lockup-mod-opinions.html

 

[dpantazis]

it might be easier to install the t/c lockup mod, a toggle switch to force the t/c to lockup when you flip the switch.

http://www.superdutydiesel.com/foru...mance/12148-4r100-tc-lockup-mod-opinions.html

http://www.guzzle7pt3.com/tclock.php

 

[SD70M]

Mine also makes some noise, when the TC locks up. It almost sounds like a combination of a chain being rattled and a hiss. I was told by my tranny guy, that it's the TC lockup clutch slipping (Or something to that effect) and that a new TC is in my truck's future.

 

[trackspeeder]

Mine also makes some noise, when the TC locks up. It almost sounds like a combination of a chain being rattled and a hiss. I was told by my tranny guy, that it's the TC lockup clutch slipping (Or something to that effect) and that a new TC is in my truck's future.

Turn the radio up you won't here that chain noise.

 

[SD70M]

Turn the radio up you won't here that chain noise.

That HAS worked so far!!!