Last week I drove from my home in Dalbeattie (SW Scotland) down to Stoke-on-Trent, a trip of around 200 miles. Did the usual (minimal) checks before setting off, all ok. As I pulled off the M6 at J16 the oil pressure light flickered. Odd, I thought. Driving round the 'D' road in quite heavy morning rush hour traffic the flicker became more frequent so I headed in to Asda at Wolstanton to have a look, knowing they would have some oil if needed. As I stopped in the car park the light turned red.
Lifted the bonnet, saw the oil filter covered with black stuff and assumed it had come loose. It hadn't, but the cooler hose union was only just hanging in there, not even finger tight.
Off I went into Asda and returned with a couple of gallons of oil (won't need that much, but it's cheap etc.) and an adjustable spanner (no kit in the disco). Tightened the union and topped up, and topped up and topped up some more...
... ended up putting more than 6 litres in.
Following the unscheduled oil change, the pressure light went out in the usual fashion (once the filter had re-filled) and I returned home the same day with no apparent ill effect - apart from a slightly queasy, nervous feeling in the pit of my wallet. I've put about 500 miles on since, and the pressure light is still behaving normally.
I think I was lucky and caught it in time, this time, but dread to think what would have happened had the light started to come on a bit further up the M6 and I had carried on until off the motorway - I now know that the oil pressure light means "Pull over and stop immediately"!
Cheers, Chas
ps: check your oil cooler pipe unions.