G60 rrrresonance

Hello again

This resonance problem is quite annoying. G60 it is and it starts the minor vibration from 2500 rpm to 3100 rpm. Interior makes noice and you can feel it also in the seats when you sit. Its worst somewhere round 3000 rpm. What might be causing it?
My cars exhaust has a little rust holes in the middle absorber (surprise). Could that cause it or, is there known cause for it? Bearings, engines front rubber support, sylinders/pistons are worn out??? Please help me to stop the vibrations and resonance!

Thanks for the quick reply! The car has been lowered - 50 mm, but the resonance was there before that, on the normal ride height. And it doesnt look like it has had contact with the rear axle. Have to check it when I begin of making the new exhaust pipe.

The drive shaft issue: The resonance can be ALSO noticed when the car is NOT on the move. You can feel mild tremors, shaking on you seat. When accelerating you can notice it MUCH better and hear.

And it doesnt make any noice it just shakes things and that causes the dash, panels and etc. make annoing rattle. The engine sounds normal also.

More ideas, suggestions?

Thanks for the quick reply! The car has been lowered - 50 mm, but the resonance was there before that, on the normal ride height. And it doesnt look like it has had contact with the rear axle. Have to check it when I begin of making the new exhaust pipe.

The drive shaft issue: The resonance can be ALSO noticed when the car is NOT on the move. You can feel mild tremors, shaking on you seat. When accelerating you can notice it MUCH better and hear. But when the tachometer shows over 3100 rpm, it is smooth, no vibrations.

And it doesnt make any noice it just shakes things and that causes the dash, panels and etc. make annoing rattle. The engine sounds normal also.

More ideas, suggestions?

How do I diagnose if its the engine mounts that are causing this? What does a broken one look like? Can you tell from the outside or do I just have to replace it with a new one? 65€ is the price for the new engine front mount.

The car has 197 000 km on meter. But I dont now for sure is that the real truth. One of you guys might have played with my meter before it was brought to here in Finland. Some meter adjustiering or what do you call it?

I showed the engine to my car mechanic friend while giving some revs and he considered its movement normal. Which means that the engine mounts should be ok. I didnt try that 1 st gear stuff because I read it afterwards.

And when the rpms were about 3000 you could feel the shaking very well when I held the tip of the pipe in my hands. I rotated the pipe as much I could but the resonance did not change in any way. I also lifted it and pushed it down also.

Should there be some sort of flexible part before the kat? Could it be that some one has removed it and that causes the shaking? I dont remember what does it got between the exhaust manifold and kat.
I have to check the exhaust when I get this project finished first!
http://koti.phnet.fi/levis/sekalais…20Valotehoa.jpg

I have been using this car for a year. But I dont stand this shaking no more. The best guess is the exhaust but I dont know for sure.
The pussy, the kat, i dont know for sure, but according to finnish "TUV" its alriguht! CO2,O2.....OK!!!

I forgot this forum...

It was not the exhaust the cause of the resonace. And the catalytic converter looks ok. I installed 2,5" diameter steel exhaust from kat to the end absorber and removed the middle absorber. The shake and rattle of dashboard is the same. I also measured the "cylinder pressure". Dont know what is called in english... Every cylinder had even result, c.a. 8,2 bar. (The thing when you remove sparkplug and push a meter to the hole and then use starter motor to rotate the engine few times).

What would be next place to look for? Bearings from crankshaft?

I also checked that counter weight was in place in the end of the crankaxle.

Flywheel misbalanced? Dont want to check this actually, too much work to remove the gearbox...and istall it back!

Belt drive was checked. Tensioner spring and guidewheel was changed from spare part car. New belt, g-lader overhaul.

Also new hydraulic "valve lifters". New valve guide "rubbers" and new toothbelt and tensioner.

No change in anyway...Hopefully oil burning will be minimized, 10 000 km/4 litres it used to burn...

Resonance has finally stopped! Not even a mild vibration can be noticed! The rear view mirror doesnt shake at all, its like all new car! Much easier to get moving or even changing gear. What did I do? I changed the rear hydraulic engine mount. And it wasnt even broken! Neither was the front mount but I replaced it anyway.