Hi guys ,I need some advice on what to do next,I got my TD5 this time last year and as given trouble from the start.The main problem was a cracked head(Diesel in Oil)the engine blew a piston one night on the way home,Thankgod i was only doing 15mph and 200 feet from my front door when it happen.The garage took it back and put a new head and five new piston heads so they say, And told me to keep it under 60mph for first 1000km,To give pistons time to bed in!!!!Which i did.There is a new head on it ,But i d,ont think they put the five piston heads in ,One maybe.It drove well for the first few months and then one night again coming home from work the whole truck slowed up.It was like i was pulling something very heavy and bad diesel knock with vibrations came into it.I then desided to drop gear box out ,because dual mass can cause that problem.This is a list of things i have done so far,New dual mass ,New clutch kit and clutch fork,New gear box oil,New injector loom,EGR bypass kit,De-cat the front pipe and a mid straight exhaust pipe. Injectors had wrong codes on them when i took rocker cover off so used nanocom to match with ECU codes.The truck drives better now ,but still as a old diesel type knock to it.The thing is you could leave it on idle for a half hour and not a sound,Even if you rev it up on idle, Sounds normal,Its only when you drive it you get that engine knock.I am now thinking that it must be main or big end bearings ,Because diesel in the oil washed white metal from them .I know that i will end up putting in a second hand engine at some stage in.But at the moment can,t not afford to do so .My ? is i am thinking of putting in a heavier oil in 10w40 part synthetic,I have 5w30 in it at the moment.If it gives me a few months more running.The jeep is a 2004 defender 90 with 92,000miles on it .Any advice welcome,Thanks lads for taking the time to read this,Regards brian.