View Full Version : DisI Oil pressure light comes on at idle

05-14-2008, 03:33 PM
I've got a 97 DisI manual. 149K The oil pres light comes on when at idle (750rpm or less) when the vehicle is warm. Currently running 10w-40 Mobil high milage oil. I changed the oil and did my best to clean out the oil pan of sludge w/o removing the oil pan(used a plastic stick and flushed about 3L of oil through the engine to try and move the sludge out. Seemed to make a difference - regardless, got lots of crap out. Anywho - light keeps coming on. Is it probable that the oil pres sensor is too sensitive? I certainly don't want to destroy an engine, but also don't want to spend a fortune chasing a non-problem. Any insight?

Les Parker
05-16-2008, 01:19 PM

Have you tried an independant oil pressure guage?
Likely the sender has reached its sell by date, it would be good to get an accurate reading though.
A new sender (RNM104) is $25.70 and in stock.

05-20-2008, 06:15 PM
I assume I need to drop the oilpan to replace that sender don't I? When I unbolt the pan - will the trans oil cooler lines move out of the way sufficiently to let me get all the pan bolts out?

02-23-2009, 08:21 PM
Do Disco 1's have a 3.9L? If so, check this out:

The oil pressure switch is on the oil pump housing. You do not have to drop the oil pan.

02-26-2009, 08:58 AM
This is an older post, but hey it has been brought back up. So you need to clean out the oil pick up tube. Remove the oil pan and clean away.

02-27-2009, 05:18 PM
If it still reads low pressure after the sensor has been replaced then you're probably looking at wear in the main crank bearings.