99 CVPI Odd Noise

Hello, I am looking at buying a 1999 Crown Victoria Police Package, The car runs fine, but a strange noise comes while driving it, the tranny shifts fine, and I had someone look at the rear end and he said there was a few scratches but nothing majorrrrr so it could have been from something else he said, the noise goes away when you let off the gas. the car needs an alignment, the tires are about 70% tread, the owner said that he had the rubber floor out and maybe the padding could have come out and it could just be road noise? If anyone has any ideas what this could be please let me know asap.
Thank you veryyy much!!!!

Can you describe the noise the best you can?

It isn't a constant hum it builds under exceleration in all gears but stops the instant you let off gas. A rear should build up with speed. the speed doesn't matter here. Although it also does it regardless of gear so that makes it hard to say its a tranny thing. I almost wondered if it isn't the driveshaft rubbing but can't find any real proof of that either. Hopefully this'll help a little bit.
Thanks again.

It isn't a constant hum it builds under exceleration in all gears but stops the instant you let off gas. A rear should build up with speed. the speed doesn't matter here. Although it also does it regardless of gear so that makes it hard to say its a tranny thing. I almost wondered if it isn't the driveshaft rubbing but can't find any real proof of that either. Hopefully this'll help a little bit.
Thanks again.


Gear noise, rear differential

I just purchased a 1998 CVPI w/97k on it and I also have this odd noise. It starts making noise around 30mph and builds in volume up to 60mph, then it quiets. I have been told it could be the U-joints. The car drives smooth, no vibration, and tranny shifts smooth as silk. This noise disappears as soon as pressure is taken off of the gas pedal, and it starts back up with any little pressure on the gas. Sounds like a high pitch humm/tone. Does anyone have an answer to my troubles.:banghead:

Almost sounds like a pinion bearing but...could be vibration or harmonics coming from the exhaust system, maybe bad motor/tranny mounts?

Engine Mounts - Unsatisfactory for Severe Conditions
Article No.
01-1-1

01/22/01

ENGINE MOUNTS - REVISED ENGINE MOUNTS FOR
SEVERE DUTY VEHICLES

FORD:
1998-2000 CROWN VICTORIA

LINCOLN:
1998-2000 TOWN CAR

MERCURY:
1998-2000 GRAND MARQUIS

This article is being republished in its entirety to update the model year coverage and part numbers.

ISSUE
The engine mounts on some vehicles may not exhibit satisfactory durability under severe operating conditions that may be encountered by Police, Taxi or Limo/Livery vehicles such as extended idling at high ambient temperatures. This may be caused by the extreme heat generated by the engine under these conditions.

ACTION
If service to the engine mounts is required, install new revised engine mounts which incorporate a heat shield. For left side engine mount, use 1W7Z-6038-BA - right side engine mount, use 1W7Z-6038-AA. Refer to the appropriate model/year Workshop Manual, Section 303-01 for replacement procedure.

I think I'm going to take it to the shop to see if someone can pinpoint this. I was hoping maybe someone has dealt with this issue before. Its a very unique sound, I personally have never heard anything like it. Man, I really like this car too, I hope its nothing serious. :banghead:

Have 98 p71 have the same noise BUT i did notice that the noise is coming from that small box in the trunk thats mounted by the right side speaker
the noise is coming from this box .what is this box ??? had the abs lite go on one cold morning thats when the noise started.. lite went off right away but the noise stayed when ya let off of the gas noise gone then back the second you get on the pedal . annoying sure sounds like some sort of feed back coming out of that box
If anyone can tell me what that box is i can trouble shoot

Holy Crap, I just looked and I also have a small box mounted to the underside of the deck, its real small with a wire running to it. What the hell is it?

:screwy: Have 98 p71 have the same noise BUT i did notice that the noise is coming from that small box in the trunk thats mounted by the right side speaker
the noise is coming from this box .what is this box ??? had the abs lite go on one cold morning thats when the noise started.. lite went off right away but the noise stayed when ya let off of the gas noise gone then back the second you get on the pedal . annoying sure sounds like some sort of feed back coming out of that box
If anyone can tell me what that box is i can trouble shoot:screwy:

this is my screen name; but i did not write that, nor do i have a 98.(???):uhoh:
what gives?

:2cents: WOW, thats weird.

The little box in the trunk is you am/fm antenna converter box. I apparently uses the wires in the rear window grid and an additonal one. To me the noise also sounds like a pinion gear. Crawl under the car and try to lift the drive shaft rear U joint up and down. Mine was so bad it moved alomost a 1/2 inch.

Well, it seems everyone is coming to the same conclusion>>Bum bearings in rear end and or gear. Anyone know what kind of rear end came in these cars(1998CVPI)?