Oil level rising 2003 diesel VX 150,000 miles.

[Lindy]

Can anyone offer any constructive opinions please? Turbo replaced last September (loss of power, fault code, smoking), still had reduced power when returned from garage. Turbo pressure valve replaced, timing belt, oil and filters changed, fuel filter changed. Advised to put a can of injector cleaner through it and thrash it. Can of BG244, initially good result, then an engine runaway. Back to the garage, diesel found in the oil and a very high reading on the dipstick. Injector seals replaced, oil drained and replaced. Ran perfectly for another month, then another runaway engine. Luckily both episodes shut themselves down within minutes. Back to garage, oil drained again, every perishable part from the diesel tank to the injectors has been replaced. Compression normal, injectors all working within normal tolerances, no fault codes since the turbo issue, no limp mode. Starts fine from hot or cold, no smoke, good power, runs fine. All work carried out by two Toyota trained mechanics.  Oil is now showing 1cm above the top mark on the dipstick again. Very reluctant to start changing injectors given the lack of evidence pointing to injector problems. Has anyone come across this before, and found a cure?