Before I contact the dealer, as it way under 6 months old, I'm fearing this will be just classed as fair wear and tear, which won't be covered.

Presume you have owned it for less than 6 months, the car is 8 years old and there is your issue. An 8 year old car will be staring to have issues through normal age.

I would suggest an oil change using the correct spec oil and a genuine filter before you do anything else.

Oil & filter changed last week by garage (not selling dealer or main dealer) using dexos 2 and genuine Vauxhall filter.

But surely even an 8 year old car, fully serviced, should be suffering with low oil pressure.

Edited by mikert on 04/03/2021 at 12:59

Oil & filter changed last week by garage (not selling dealer or main dealer) using dexos 2 and genuine Vauxhall filter.

Dexos 2 is sold in several different specs, has the garage used the correct one or simply one they had to hand?

Dexos 2 5W30, that's all I know. Google only brings up 1 spec though.

All previous services by Vauxhall main dealer, so assume they used correct one