oil leak on a 88 gti engine, any ideas???

[lunch box]

ok I have an 83 rabbit gti with an 88 gti engine in it. i jus bought the car 3 days ago and the guy i bought it from said it was leaking oil from the oil filter. I looked at it and the oil filter o-ring blew out so i bought a new one, drove home fine. then today it does it again. i have 15w 20 oil in it. another thing is when the car warms up the oil light comes on. then when u rev it pased 1500 rpms it goes off.

p.s. im new to vw as well

[veedubmechanic]

Prob leaking from the oil cooler seal, the one that goes between the oil cooler and the bracket that bolts to the block. Or the low oil pressure sensor on the oil cooler housing is leaking. The sensors tend to leak when they get old because the sensor is plastic and the housing is metal. Also check the oil sensor on the side of the head and valve cover gasket for a leak.