the fault on the engine is that the bolts/studs that hold the big ends onto the conrods were to small a diameter, thus through time usually 60/70 thousand they begin to stretch thus knocking the big ends out , I drive the early navara 2.5td d22 2001 it has a much stronger motor, mine is now over 170,000 ,if anyones after a navara theres an outfit near to me buys them in with f,,,,d engines ,rebuilds them and modifys the problem and gives you a 2year warrenty on the bottom end ,and hes quite handy price wise, I can pm his number if any ones interested ,Newcastle area