I have got engine overhaul on carby Mehran few months back. Done about 4000 km till now. Used Shell Helix 10w-40 SN grade till first 800 km and then switched to ZIC 15w-40 SJ grade oil. Tappet noise on day 1 was very high and reduced a little bit till now. When engine warms up or on acceleration noise increases and heard in cabin. The mechanic has tightened tappets 3 times, but noise remains there.
