OK the oil light just lit up on the 4x4. it then went off and has flickered, so where should I start my checks. I have checked the oil level which is fine. I have also ordered a new sender but it wont come till tomorow.

Any ideas?

 

get a pressure gauge, simple as.

 

did it come on while it was hot and you were braking hard upto a junction...? is so - just oil surge, just make sure the level is ok...