Engine Number Location

For a 1.5, 2.5 or 3.5L Jaguar, the engine number is stamped on a raised section cast into the block on the exhaust side, on the side of the block at the back. 

There are a few with no engine number.  This is rare but occured if the factory had to supply a replacement engine to a new car that developed engine problems.  The dealer should have stamped the same engine number as the one the car was originally supplied with, but often they did not do so.