i bought the 2.5 for one reason alone and that was the noise that it makes! i went into this blind! never got any info on them beforehand! i read with so horror about 4k repair bills for failed engines! what can i expect to go wrong or prevent before it happens? a brief history of the car is i got it with 80000k on the clock its now on 85000k the cam belt water pump and fuel pump belt were changed at 79000 and the oil and fuel filters have been changed every 15000k with fully synthetic oil! its the 163 front wheel drive sport model! im new to this forum! but have ran audis for 10 years my 1.9 has only cost me £15 in five years of ownership(repaires not servicing) and all that was,was an engine temp sensor! love my avant but if im gona get 4k biils i would rather chuck 4k at trading up! dont want to do this as i think the b6 is the best looking a4 by far!