Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Turk on 12 December 2007, 20:00:20

Title: Engine mounting bushes (Facelift 2.5td)
Post by: Turk on 12 December 2007, 20:00:20
I have a rumbling at idle and I get a vibration thru the floor with a humming noise when travelling at 60mph+.

I've recently done the DMF(old one was well kn@ckered !) and fitted complete t/rods assemblies both sides. The wheels have new tires and have been balanced and re-checked.

I accept that as I have used the 17" alloys off my Elite the lower profile 235/45-17's will give slightly more road noise, but this is not due to road noise. It's a low to mid frequency humming sound, similar to a noisy Diff.

I've had a look underneath and the only thing I can see that may be a problem is the engine mount bush on the passenger side looks ok. No cracking and a domed appearance but the drivers side is concave or dished not domed, and I can see a 1cm split along the circumference of the bush.
I know these are sold as left and right hand application, so I'm not sure whether mine are ok with the passenger side domed and the drivers side dished or whether the dished drivers side bush is kn@ckered.

Before I did the DMF the engine would shake violently if left idling and this would not have done the mountings much good.

Any ideas folks, should both bushes look the same and if one is kn@ckered, would it cause the rumble at idle and the humming and vibration at 60mph+ ?

Title: Re: Engine mounting bushes (Facelift 2.5td)
Post by: hotel21 on 12 December 2007, 20:18:36
Have you tried driving the car on a private runway then switching engine off to see if rumble stays or goes?  TAKE CARE to only click back to switch of engine and not too far to lock steering!!

If stops when engine stops, its up there somewhere.  If still there, buckled rim(s)??

Just rearead - rumble at idle as well as noise when at 60+...   ::)
Title: Re: Engine mounting bushes (Facelift 2.5td)
Post by: Turk on 12 December 2007, 20:55:37
You're not far off the mark by suggesting buckled rim. I noticed the front drivers side was not quite true when I balanced them on the machine at my mates MOT station. I put that on the rear for now. Dunno how that happened. I've not hit any kerbs or deep pot holes.

Yeah, got a rumble at idle too, I'm concerned about the engine mount bushes. They just don't look right with the passenger side domed and the drivers side dished.
 
I reckon they may have had too much stress b4 the DMF was done. When I say the motor would vibrate violently if left idling, I  mean violently !!
On one occasion, the guy doing the air con re-gas started moving away from the car with a very worried look on his face. It would stop if i depressed the clutch and let it out slowly, but he wasn't at all happy when it first started.

If they should both be the same in appearance then the drivers side has failed and that would allow the motor to sit almost 2" lower. I didn't measure the distance between the mounting points and compare. Only just thought of that...Doh !!  Not that I have anything as to go on as a reference anyway.

I reckon it could well be a failed engine mount, I just don't wanna pay 55 squid plus VAT, and still end uo with the same problem if there is no fault with the bushes differing in appearance.