when trying to accelerate i feel vibration. i feel it only 1000-2500rpms. i changed spark plugs and it help a little but it still don't feel right. maybe plug wires? Speed doesn't effect vibration.

what u think?

car Audi A6 2.4 2000y.

 

Any DTC- CEL ?

How is the power, fuel consumption ? fuel filter
Under speed you mean rpms?
BTW - what is your transmission?
Mileage of the car => transmission or/and engine mounts

 

under rpm i mean motor speed. car moving speed doesn't effect vib.
power loss is not big but a little difference. sometimes accelerate better and sometimes not. mileage is ~133000. fuel filter con. unknown. i need to look at service book. transmission is manual 5 speeds and eats little more fuel than usualy.

in dasboard there is no warning lights
car is not jet connected with computer but its feel like missfire

 

Misfire will always trigger CEL=> this is due OBDII and emissions standards.
Change the fuel filter, purge the fuel system - as you are in Europe somewhere? you have access to LiquiMoly products - Ventil Sauber and Jectron Cleaner are the best, proven for years (forget the Seafoam). Concentration is the key - one bottle each with 3.5l of fuel.
133k km I presume?
Check the mounts. (looks like the system is getting into a resonance)
BTW how do you feel the vibration – longitudal or across?
Do the gears affect the vibration - 1, 2, 3,...

 

consider that if the vibration is only at lower RPMS the problem could still be there at higher speeds but human perception becomes unable to differentiate them when the vibration exceeds the perceptive differential threshold.

I'm going to suggest check your control arms and ball joints. At low RPMs the small amount of torque applied might be shifting the wheel assembly out of place (shot bushings) throwing your alignment out causing vibration. When you get off the gas less torque means hub returns to normal position and vibration stops.

 

maybe cv joint. Front right clamp was loose and loosing grease.
i was trying to move it but there wasn't no strange movement

 

Oh, good thing you caught that. Get a cv boot kit soon and fix that before something worse happens. how about getting wheels balanced and alignment checked?

 

week ago i changed winter to summer tyres. nothing changes. then cant be wheel problem. alignment was checked ~10000 km ago but then wasnt that problem. when fixing cv rubber clamp then i see its condition. but can control arm, ball and cv joints make to vib whole car.

 

my fuel filter was very dirty.
i did short test drive and now its feels fine.

 

Glad you got it worked out. Fuel filters are a commonly neglected regular maintenance item. I've heard of people that change it every other oil change.