I've been having a recurring issue where the oil light flickers or goes solid at idle after highway speeds. This first happened at the Eisenhower Tunnel on the way up to the mountains for a ski day back in March, which was a pucker inducing moment. The oil level checked out fine (full) and there was no ticking indicating low oil pressure. This happened 3-4 more times sporadically over the next few months. I inspected the oil pressure switch and it wasn't leaking or weeping that I could tell. I decided to replace it about 3 weeks ago and I've had no oil light issues since then, even during this 100 degree heatwave we're experiencing this week. Luckily it's only a 5 minute job to replace the switch.

I previously replaced the switch about 3 years ago with a switch from AB that had a weep hole. The new switch is a different style with no weep hole which Rimmer Bros claims is a LR genuine part.

FYI - Per AB, if your Disco has a sepentine belt, only use the o-ring for installation.


Replacement switch style




Old switch style

 

Oil pressure switch . I had the flickering at idle . I changed the switch out and it continued to flicker only after it warmed up and at idle. I did some reading and used a quality engine flush , changed out the oil and added cheap filter , drove around the block a couple times and added a new filter after dumping the oil and adding a heavy duty diesel engine oil(on sale at walmart for $12 for a 2 gallon jug) and an a S.T.P. oil additive for extra oil pressure & lubercation. I have not had any flickering oil pressure light come on since ! This worked for me . I did check the oil pressure before any of this at the port were I replaced the oil switch and I had almost 50lbs. If it was lower I might not of spent the money for all of this ?