Low rumble at acceleration

1989 Volvo 240 DL.

When the car is under heavy load (4-5 people, added weight of about 600lbs
(big friends)) the car will tend to rumble a bit, as if coming from the
underside of the car, and vibrate a little, like from the rear wheels, when
coming out of zero miles an hour. Once it is going it is sluggish (as
expected with this kind of weight) but is fine.

There is also whirring noise when the car is at 50 miles an hour coming from
the rear. And at 55 MPH, with just me in the car (170 lbs) it'll do a
similar rumble noise from the underside.

Is this the exaust vibrating maybe? It is missing the front muffler (between
catalytic and rear muffler (behind the gas tank)). Thanks, I know this is a
weird one.

Cheers,
Hector

 

Michael Cerkowski

And the U-joints (starting/low speed is usually the front one). I've
seen far more of them go bad than carrier bearings.

Bill

 

Exhaust rumbles can usually be reproduced with the car not moving,
by putting it in Park (or neutral if a standard) and slowly revving the engine.
If it only does it while moving, have the 'carrier bearing' in the driveshaft
checked.


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http://www.albany.net/~mjc1/index.html

 

It's the angularity on the center driveshaft bearing when the car is
heavily loaded. I noticed this when I lowered my car with IPD stuff.
The solution was to space the bearing down about 1/8" with washers
between the bearing mount and frame. I did this 4 years ago, and the
noise has not returned.

Forrest