strange sound

[thinmana]

Has any one heard a pressure relief type sound coming from their engine, when under full acceleration????????????

Sounds like this "fffffuuuuuuuuuaaaaa" but not everytime.

I hate to take it to the dealer. Seems we know more than they do.

Thinman:help:

[MAD-3R]

Hmm Not sure. Could it be the compresor for the defroster disengaging?

[jefferson-mo]

Tell you what I'm gonna do.............I'm goin' to lunch in a couple hours...........how 'bout I go make some full throttle runs.......................you know--research

:banana2:

[grzellmer]

Under WOT my MM makes a slight whistling noise. Hard to describe it but my believe it is just the air running through the intake.

Now if there was a blower pushing the air in.....

[LincMercLover]

grz,
I think we determined that would be the tranny operation, which is normal.

thin,
I think we found there's a valve in the intake that relieves back pressure. Possibly you're hearing this?

[thinmana]

Thanks for the input. It seems to be more prevalent when engine is not quite warmed up.


But it does sound like a pressure relief sound.

[thinmana]

Thanks, lincmerclover

The torque converter has a wine to it at higher revs just prior to shifting to next gear.............. But I can understand that and deal with it.

[TripleTransAm]

Originally posted by thinmana

The torque converter has a wine to it at higher revs just prior to shifting to next gear.............. But I can understand that and deal with it.


First off... absolutely NO flames intended by the following comment, it's just an observation of mine.

Observation: I've always found Ford AOD transmissions to be whiners at lower gears. Sometimes to the point of being audible from the exterior of the car. Nothing like the gear whine you get from a manual-tranny FWD 4-banger, but a kind of big-industrial-size-electric-motor type of whine, tonally-speaking. I wonder why.

This stands out in my mind mostly because I don't hear that particular type of sound with General Morons (er, General Motors) 4-sp auto trannies (although I remember some tall-diff-geared 3-speed Hydramatic350 from the 70s making their own unique type of whines as well).

Maybe it's the cut pattern on the planetary/sun/ring gear teeth? Maybe it's the torque converter design? Maybe it's an issue of pump design?

I really am curious...

FWIW: I did not notice this whine in the Marauder, although some recent Grand Marquis did exhibit this sound. Then again, I was too busy concentrating on the sweet exhaust note of the Marauder. :D

[TripleTransAm]

Originally posted by thinmana

The torque converter has a wine to it at higher revs just prior to shifting to next gear.............. But I can understand that and deal with it.


Blast my slow typing fingers... I didn't notice this post when I wrote my previous reply... so it IS the torque converter, then. I've just always been curious about this. Sorry for the wasted space in the previous post.

[LincMercLover]

I don't believe it is the TC making that whine, as it's comeing from the back of the car. I do believe it's the 8.8" rear ends that do this though...

[WolfeBros]

From what I can tell from the way you guys drive, that whine is most likely coming from a police siren. ;)

[jefferson-mo]

Is that what that was....I thought it was all those cams and valves approaching redline...............:burnout :




:banana2:

[Marauderman]

WolfeBros-----Oh thats good ...real good..!!

[Beadhead]

jefferson-mo: just tell the friendly officer that "it's only an experiment -- you know, in the interests of research for my friends on the MM board" ... ;)

[martyo]

And tell 'em Sarge said it was "OK"

[martyo]

Oh yeah, and if that fails, tell 'em that mensrea is your attorney...

[bugsys03]

maybe hes got an old gm 2 speed--they sounded like that

[thinmana]

In my state the troopers speed up to get a good look at the MM.

I've had it happen several times.



:burnout:

[SergntMac]

What noise are we talking about again? That "whooosh" of air after backing off a WOT run? I got that, and I think its a neat sound.

Now you want to talk about tranny whine, any one remember the Muncie 220 "rock crusher" of the early '70s? Could hear that screech a block away, no s**t.

Wolfe...nice one...LOL.

[thinmana]

In my state the troopers speed up to get a GOOD look at the MM.

I've had it happen several times...................