Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Valentin on 10 April 2025, 14:57:25

Title: Vibration noise few seconds after starting the car
Post by: Valentin on 10 April 2025, 14:57:25
Hello everyone,

As the car is new for me, maybe I don't get all the small particularities of it.

When I start the car, I can hear a noise like a vibration, and we can feel that vibration in the steering wheel. It lasts for a few seconds, maybe 20 or 30 seconds and then it disappears.

It sounds like a small pump or something running very high rpm, maybe totally normal, as I didn't find any post about that on the forum.

Can anyone tell me what it is just for peace of mind  :)

It's on 96' MV6 ;)
Title: Re: Vibration noise few seconds after starting the car
Post by: TheBoy on 10 April 2025, 15:12:51
On the 2.5/3.0 engines, they have secondary air injection for emissions purposes. It runs for a few 10's of seconds upon cold starting, to aid warming the cats.

The pump sits behind the front bumper on the left side, and can get quite noisy with age.  The other failure point on that system is the one way valve that is supposed to stop exhaust gas pressure leaking back through the pipework and pump.

Easy to tell if that is the cause - unplug the pump.  If that cures it, your choices are to fix the setup (why?) or block off the SAI pipes near the manifolds and rip the rest out.
Title: Re: Vibration noise few seconds after starting the car
Post by: Valentin on 10 April 2025, 15:33:53
Thanks a lot for the extra information :y