I bought a honda civic 90 around 6 months back and suddenly one day it started giving grinding and knocking sounds from engine. These noises were not persistent they seems to fade out randomly while driving. I showed it to one of the mechanics and he adjusted the tappet and said that the noises were coming somewhere from beneath and he will have to open head to check the issue. After opening the head he said that the engine block has rusted and it cant be repaired you will have to replace engine completely (confirmed from 2 mechanics)
(Note : My car's engine oil never used to drop level, also there was no smoke from silencer and had no issue in speed or acceleration (tried 130 km/h easily on CNG)
Needs help with professionals on this case with following questions :-
1) Which Engine should i buy ? Model number
2) Can i use civic 95 engine in my car or it will have compatibility issue (wiring and stuff) if yes model number plz ?
3) From where i should buy engine ? (residing in karachi)
4) how much it's going to cost roughly ?
5) How much it costs to register a new engine number on my chasis in CPLC ?
6) How long does it take to change an engine ?
7) whats the price difference between new engines and used ones at shershah ?
8) Are used engine trust worthy ?
9) Do new engine have any guarantee ?
Thanks in advance !