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[Temetsy]

So my pfl omega 2,5 v6 manual has developed a nice shake that shows up only when wet. It is connected to engine speed so not any drivetrain issue Thought of the DMF but the fact that it shakes mainly only at wet conditions got me overwhelmed  Said shake also dissappears when taking sharp turn to left.

[tidla]

ignition fault? water pouring over the coil pack?

[Temetsy]

It doesn't feel like misfire etc, just like the whole damn engine is unbalanced and forgot to mention that it shakes when I brake with engine too so that rules out ignition and fuel issues.. At idle it runs fine but when i get over 1k rpm the shaking starts.

[Diamond Black Geezer]

Are you sure it's not a misfire? V6 engines are naturally very nicely balanced engines, but a misfire would only show up as a 'shudder' under certain revs. DIfficult to explain, but think how the car behaves over speed bumps at different speeds. Go over them too slow, and the whole car pitches and lurches, go a bit faster and it glides nicely, a bit faster still, and you have a shock to your spine. Hope that makes sense. A better example would be wheels that aren't properly balanced - they don't shudder all the time - but only at certain speeds. Above and below that, they sort of 'even out'

Worth looking at the steering etc.. but strange how it only occurs over a certain rpm... 

[Temetsy]

I'm 100% sure that it's not a misfire because a) coil pack, leads and plugs are only 3 months old  b) the shaking/more like vibrating is present also when not even touching the gas pedal. Steering is fine tho front wb bushes are torn but trust me, it is not steering or gb/prop/diff  It is just this vibration that appears even when revving stationary and clutch's position makes no difference, vehicle speed-no difference nor what gear is in makes no difference so i think this rules it down to engine   Frequency of the vibration is clearly connected to engine rpm and is very 'even' so to say. Doesn't feel like some pot misfires now and then, just this damn jackhammer -like vibration that makes the whole car feel like it has massaging seats :

[Broomies Mate]

EML on?   

[Temetsy]

Nope, no eml No loss of power, no difficulty to start, no stored codes, no problem in running. In fact runs like new when it's dry

[elvin315]

What about a broken right motor mount? It could explain the shakes stopping when turning left. The engine's mass would shift to the right, pressing down on that mount and not allow the shakes to be felt. Doesn't explain the part about the wet though. That's all I can come up with. Sorry.

[Temetsy]

That really might explain it, since it's just vibration and not any sounds etc. Checked mounts and it's not even properly seated on right side Could f00ked mount really vibrate the whole body that bad? I have older type W-shape rubber mounts with no fluid filling. Propably better get two new filled mounts.. Damn expensive tho

[Diamond Black Geezer]

Is that right? Earlier cars (prefacelift?) didn't have fluid-filled mounts, as per below? I always thought all Omegas had silicone filled engine mounts.

http://www.partsbase.org/opel/omega-b-1994-2003-5-5-6-1-engine-mountings-front-mountings/#p-ope-5682503

[Temetsy]

Nope, my organ donor mfl had fluid filled mounts. Tho they were almost empty at that point.. And i think i'll fit those mounts that arw marked with n. "4" on that picture Sits straight to old mounts or am i wrong?

[Diamond Black Geezer]

I'll try and check tonight.. you've got me thinking now.... 

[Temetsy]

Thanks, i wouldn't be surprised if they were different thinking all of these small annoying changes made to v6 making hunting for spares interesting at least

[terry paget]

I presume those hydraulic dampers are fitted only on automatic g/b Omegas. I've never seen them on an Omega. I last saw such a thing on a FWD car - Austin Maxi and Citroen CX.

[Temetsy]

That might be since the organ donor had originally an autobox. How do I reach (LHD) driver's side mount because theres all kinds of stuff in the way