HI I got audi a4 2008 2.0t multitronic just got from service on 161....km now it has a vibration now and then but for few minutes with less power.what can it be?

is your engine light coming on? if it only shudders periodicly it could be either a mount going bad or a coil pack going bad.

Thanks,no engine light coming on just vibrate like dead spark plugs but coming from service,and they told me camp belt was never been changed from the first owner cause i have only six months now with the car.

whats the mileage of the vehicle ? this modal has a timing belt in it it may have lost some teeth on the belt. I would advise having it done asap if the car has 161,000 km on it and im surprised it lasted this long if it hasn't been done yet as its coming up on its second change in 20,000 km from now. The vibration tho can still be a bad mount acting up. A loose engine or subframe mount can cause this kinda of issue so i wouldn't rule it out. How often is the shakes and is it eratic or at certain rpms? certain speeds? go to your car and test it keep the car in park and rev the engine to 2000 rpms and try to hold it steady. Most vibrations happen around 2000 i find in the vw's and audis if something is loose or not quite working right. Let me know if its eratic or constant. you can safley rev to 3000 rpms for a short time in park to test.

Thanks,the thing is when vibrate the sound of idle change and the whole car shake like misfiring for short distance or until i switch it off and become normal again.km are 161812

Does it has camp belt or timing belt

well only thing i can say is go get the car scanned if it miss fired the engine light would have gone off. so im sticking to the thought that you most likely have a bad engine mount or your timing belt has started to go. and regardless of what goes on you need to replace the timing belt asap before it does break. While your in in there have them check for loose or warn out pulleys that may be causing the issue. When you do have the cars timing belt done either you can do it yourself and get it done cheaply or take it to a VW/Audi specialization shop and it should cost roughly 800 Canadian or 400 pounds if your in Brittan since it looks reversed of my style car. **Replace The Pulleys, Belt Tensionor, Water pump, Thermostat, and all related hardware.** I would recommend finding a kit then hitting the garage up. a couple weblinks will be posted bellow for an idea of the parts i listed.

http://www.blauparts.com/proddetail.asp?prod=GH21621-1-A http://www.autopartsway.ca/partlist.cfm?audi/2008/a4/base/2l-l4/allb/engine/valve-train-components/engine-timing-belt-component-kit/pagenum1/tabs I would vote for the advanced kit tho since you will need the parts regardless. http://www.blauparts.com/proddetail.asp?prod=GH21129