the warranty is expired, so they have no obligation to fix it.
You may find that is not exactly correct under law. Manufacturers promote arbitrary warranties on their products, which are often determined by competitive factors rather than expectations on actual lifetime. A consumer can usually rely on repairs to be carried out within this period pretty many no questions asked.
Outside stated warranty periods, consumers are still protected by statutory warranties which are mandated under law and basically state that a product has to be fir for the purpose for which it was sold.
This is an extract from the NSW Department of Fair Trading’s website...
Statutory conditions and warranties are implied by statutes or common law and require traders and manufacturers to ensure that every product provided is suitable for the purpose for which it is supplied.
...
For example, a refrigerator is an expensive item. It is not unreasonable to expect it to last longer than 18 months before it’s ready for the scrap heap. Even if the voluntary warranty on the refrigerator has expired, a consumer may still have a valid complaint under the law if it had a structural fault eg. defective insulation not apparent at the time of purchase, which became obvious after only 18 months.
These statutory warranties cannot be excluded or modified by a manufacturer or trader when the product or service is bought for personal or domestic use, even if the consumer does not return a manufacturer’s guarantee card or notice provided with the goods.
One could argue with this logic that a critical engine component, which most mechanics would agree should last the life of the engine, failing after 3.5 years would make the product unfit for purpose. This argument would be strengthened by the number of cases which seem to be surfacing; it was also not an issue facing other models by the same manufacturer.
I am not stating that if this was tested in court that the consumer (or Holden) would win, but I think it shows that there is reason for Holden to want to sort the problem out amicably with their customers on a case by case basis. Not sure they would want to risk an unfavourable court decision setting a precedent.
As to the extreme examples where owners of very old vehicles are attempting warranty claims, I would imagine that this wouldn't apply because those vehicles have been fine for such a long time and lived up to the typical lifetime expectations. It would be accepted in the mechanical industry that pretty much anything can break with an old car.