ACCENT CRDi complaint about engine which is troubled at 85,000Kms

Dear Sir,I am the owner of Accent CRDi it was purchased on11.11.2003 and registered at RTA, HYDERABAD A.P. from time to time I am following the guidelines and every 5 thousand K.M. the engine oil and filters are being changed as per your advice.  now the car run around 85,000 Kms, recently that is on 24.7.2008 I got it checked to computer polution and got O.K. certificate. be that as it may on 12.9.2008 all of sudden it started eminating smoke from silencer, I am told that there is wrong with the engine and adviced atleast 70,000/ will be cost of replair. I am shocked, my vehicle No.AS9 AH 5689 with Hyundai service station, L.B.Nagar X Roads,Hyderabad. it may be treated as legal notice. my e.mail nagbehara@yahoo.co.in