Markymark replied:

I believe it's something along the lines of the injectors are driven by the oil pressure and if the incorrect grade of oil is used, there can be problems of all sorts.

Member - Bruce and Anne replied:

The problem is not the injectors but the injector seals, and Holden should have fixed this under a recall. It was a big problem with the 3.0 litre in the first ones that they producted. So tell him to take it to Holden and see what they say.
Cheers Bruce

Darian (SA) replied:

Indeed - as Bruce says - it was the injector seals - they we recalled on the basis of safety, because the leak could cause the motor to surge and had the potential to toss people into a "situation". Mine have been done twice on recall (or so the dealers said - while it was in for otherwork - but I've never had an issue with the injectors causing problems - vehicle has been good overall so far - beig essentially a safety issue, there may be no limitation on when it can be done - any dealer should be able to bring your VIN number up on their national tracking system, and see if the seals have been done at some stage. I think my second recall was for a revised, improved type of seal (once again, so the dealer involved "said").