My ones being bought back also, initially it passed. After i removed the tub to clean it i found quite a few holes with the needl gun. Opened new case with Nissan and they made me a decent offer. However with the money i cant afford a newer D40 which i could try protect before it rots so im considering a D22 if there any decent ones. I know they had engine issues, is there a date they were modified or recalled regarding the engine issues?
D22's were NEVER re-called for the engine defect, according to Nissan blowing up an engine at 70mph in the overtaking lane of the M25 or M6 was NOT a life threatening, dangerous event!
Even very late ones 2005 were blowing up, Nissan never acknowledged the fault, therefore they never stated a safe build date, IGNORE the safe engine number bo**ocks, this mis-information never existed, it was a figment of imagination from another website.
Trucks with replacement Nissan OE engines are no better, as there is NO way of knowing the replacement engines age, commonly they blow between 60-80,000 miles, but have been known to go at 30K and in excess of 100K miles.
IMHO the only safe ones are upgraded ones using the correct parts, either by a competent, decent and honest owner or Billcar, either way demand to see receipts proving the proper parts were used, there are other self appointed YD25DDTi engine experts offering cheap rebuilds, avoid these like the plague, never buy one with a re-ground crankshaft!
Your problem might be that once upgraded, owners seem to hang on to them, as they are very good, reliable and economical trucks, not one upgraded truck has blown it's engine, that's over 10 years now.