peugeot 306 dt rear engine block - kyle richmond
does anyone know what the hole is on the back of the engine block near the rear engine mount, as it is threaded, is there some kind of sensor or plug, its above another kind of sensor,near the sump
peugeot 306 dt rear engine block - DP
coolant drain plug?? Some 306 dt's have it, some don't. Mine (a 98) didn't.
peugeot 306 dt rear engine block - IanT
My 1993 DT doesn't have any wiring for sensors in the area you describe, and its coolant drain plug is at the other end (flywheel end) of the block.

Since the hole is close to the rear engine mounting, my guess is that it is an alternative location for the mounting when the XUD engine is fitted in other models.

Ian
peugeot 306 dt rear engine block - kyle richmond
Found what it was, i forgot the turbo feed pipe