1989 740 Oil warning light on dash

[elvee55]

I have a 1989 740, recently the oil warning light has been flickering after the engine is driven and warm
there is a noticeable ticking noise, The light disappears after the engine is switched off and rested for 5 minutes or so but comes back on after travelling a short distance. oil levels are good and new oil filter was fitted,any advise appreciated

[lummert]

An oil pressure test with a real oil pressure guage is needed before going any further with diagnosis.

[mtd240]

An oil pressure test would definitely help - but see if wiggling the sender wire (with the engine running) causes the light to flicker on the dash. The oil pressure sender wiring is prone to degradation - it squeezes between the accessory bracket on the block (lots of chafing), goes under the timing belt cover (where it is coated in oil from leaks) and then plugs into the sender on the exhaust side. I recently worked on a 740 with a flickering oil pressure light, and that wire was the issue - it was grounding out on the driver side accessory bracket. Ran a nice new wire with OE-ish wire sleeving (something like this) to protect it from oil/heat/abrasion for another 20 years/200,000 miles.