2.5 NA (12J)

Engine parts and Ancillaries for your 2.5L Naturally Aspirated diesel Defender (Engine Code 12J)

Launched shortly before the short-wheelbase Ninety model in 1984 was a 2.5-litre diesel engine. A more modern injector pump improved fuel economy and an improved glow plug system improved cold-starting performance.  To reduce engine weight, extensive use of aluminium castings was made for the cambelt case, vacuum pump, rocker cover and other parts. Other small improvements were made such as the fitment of a spin-on cartridge oil filter instead of older, harder-to-change element type and the fitting of under-piston oil jets.

The British Army used this engine in the vast majority of the 20,000 Land Rovers it bought between 1985 and 1994.  A manufacturing flaw with pistons combined with Army maintenance practises (such as a tendency to over-fill the sump with oil) caused the engines to over-breathe and ingest their oil, leading to piston failure. Late military-spec engines had a centrifugal separator in the breather system, allowing excess oil to drain back to the sump. These engines were designated 13J and 11J (ref Land Rover Defender Military 110 1991 Supplementary Parts Catalogue). These later, modified engines were the first in their class (small capacity high-speed diesels) to pass the Ministry of Defence's arduous 500-hour durability trial.