Noisy vibration

[bukky]

Maybe you have an idea and solution to this problem I have with my volvo 480 turbo automatic 91 model.

When the gear is engaged in drive and I begin to accelerate I hear the noise and feel some vibrations like an exhaust pipe flaping against the underbody of the car just around and behind the accelertor pedal inside the engine compartment or firewall.

Noise and slight virations usually occur when accelerating from stop and at low speeds, but when cruising, there is no noise nor vibration even when I deccelerate or accelerate at high speed.

I have re-tightened all the nuts and bolts I could find underneath, all engine mounts, but the noise and vibrations still pesist. Have also checked the whole exhaust, no contact with body whatsoever.

The engine is great and runs smooth, the problem is when I begin to accelerate from stop with the gear engaged both in drive and even between 1-3

Do you have an idea what could be wrong? or anyone with such an experience and possible solution?


The vibration could also be felt slightly from the accelerator pedal and lower part of the steering column that bring noise to the interior

Bukky


Moved to Power Transmission (40)

[Ernie]

I think you have a problem with the visco coupling.

if the noise is similar to the rattling sound my 480 once made then prepare for bad news ... after removing the auto box and the visco coupling it appeared that the teethed wheel (for starter motor) that is attached to it had several radial cracks and even some pieces of it were missing The bad news is that you can only see this after removing box and coupling ... which is a hell of a job.

[volvofox]

whow... ernie..yes this is how bad it could get...

but maybe bukky has a worn engine rubber. so the engine moves more than normal, and the exhaust really hits the firewall as accilerating....
so advise before you tear out the whole gear box.... check rubber mounts. !

[Nille]

I think I know what you are talking abuot, Bukky. If I am right about the sound youy are talking about, it can not be related to the teethed wheel. The sound of this noice clearly indicates that vibrations from the engine are getting in contact with the chassis of the vehicle but only at low RPMs. Exhaust is the typical reason for this sound, but you have already checked that. I would then go to the engine and gearbox rubber mounts and inspect them for wear. If nothing is wrong here, inspect the linkage between the gearbox and the gear stick. It might also be worthwhile to inspect the little tilt/vibration damper cylinder, which is located on the right side of the engine.

[Gez72]

Hi ,

Did you ever get to the bottom of this issue ?
What was the problem?

[jifflemon]

Given the original post was from 2004, I’d suggest making a new one if your suffering from similar issues!