Hi, I have a 1996 Volvo 940 LPT. Oil pressure warning light flicks on intermittently when slowing down. Engine never dies and tick over ok, no strange engine noises. Can anyone suggest where to look for the problem please? Thanks.

 

hi

what is you oil level like? the oil light will come on when the oil level is so low that under braking or acceleration, the sloshing of the oil in the sump is sufficient to momentarily prevent oil being picked up by the oil pump. Braking or accelerating will cause this movement of the fluid hence the flickering of your lamp.

If the oil level is ok, the it is best to remove the oil pressure sender and manually check the oil pressure against the service manaul specs. Oil pressure is lowest at idle and then rises to a max point when the regulator cuts in to reduce pressure. Unless the engine is revved very hard, the pressure valve wont need to activate. If the measured pressure is all ok and oil level is ok, then it points towards a faulty pressure sensor itself. Potentially a wiring fault could cause the light to flicker, it depends if the sensor provides voltage to the lamp when oil pressure drops or instead if it provides an earth connection (ie other side of lamp has a permanent positive feed and earth provided by the sensor or vice versa). Replacement of the sender isnt hard and the part isnt expensive.

but, you dont want to leave things too long before you investigate. First off, check oil level is ok. When was oil last change? oil thick ie potentially the sender is block up and not measuring actual pressure?

good luck and keep us posted!

Shimon

 

Hi, thanks for your message. Had an oil and filter change 8 months ago at a garage. Will change the oil and fit a Volvo oil filter. Could you please tell me what size socketI need for the oil drain plug? Oil level seems ok. Thanks, Jane