What oil pressure on 2000 Nord engine

jimmyjam · #1 (**Post Link**) 09-03-12

When happy what should the oil pressure gauge be showing on my 2000 Nord engine and what is unhealthy!
I ask because it moves up and down as I imagine it should in conjunction with revs/speed but recently the red light has been flickering on for long periods. I'm used to lights flicking when they shouldn't but am wondering if this is now more serious?

spiderserie4 · #2 (**Post Link**) 09-03-12

oil guages are notoriously unreliable.

The red light flickering, on the other hand, is something you must attend to. One thing is good, the red light is working! The red light is supposed to come on with the ignition, then go off immediately the car is started.....and stay off (it goes off at ca. 5 psi)
Check the wiring to the sender is not loose (single wire), or the connection is not corroded or wire chaffed and earthing out somewhere as the engine is shaking - if it earths out it will turn on the red light. (on my 1990 spider, this sender is screwed into the left side of the engine block, just behind the alternator)
You can pull the wire from the sender and earth it and you will see the red light goes on.

My 2.0 spider (hot engine) runs on the motorway at ca. 60 psi and ticks over (hot engine) about 14 psi......but that is again reading the guage....actual readings might be slightly off.

If you really want to find out the correct oil pressure, take out the "low oil pressure warning light sender" or the "oil pressure guage sender" itself (whichever is easiest to get at, usually the oil pressure warning light sender) and screw in an oil pressure tester in its place (tester guage looks like a cylinder compression tester) - then you will know for sure.

harryf · #3 (**Post Link**) 09-03-12

The official Alfa handbook does state that the 'oil pressure light should go off when accelerating the engine from tickover' In other words they consider it OK to have the oil pressure light on at tickover, but not above.

If you are running modern synthetic or low viscosity oil (less than 20W50) then that can cause low oil pressure. Also worth seeing if your tickover is a bit low and needs increasing.

I ran synthetic oil in a Nord engine for a while and when hot the oil light came on at anything over 1500 RPM - I soon changed back to 20/50 oil.

If the light only comes on flickering at tickover I would not worry.

jimmyjam · #4 (**Post Link**) 09-03-12

Thanks all, good advice, will look into it

Cosmo · #5 (**Post Link**) 09-03-12

As an aside: The Jaguar V12 engine had unusually high and variable oil pressure. It was common for hot idle to be less than 8 psi with the upper end at 80-100 psi. The needle would flick between the two extremes to such a degree that it was reported as a fault by a lot of drivers. So many so, that later revisions of the oil pressure sender were just simple on/off switches with a resistor. This turned the linear 0-120 psi gauge into something that only had two states 0 psi or 40 psi

spiderserie4 · #6 (**Post Link**) 09-03-12

if your revs are too low at tickover, the light will flicker too....but it should definitely go off and never come on when you are driving, at least not on a healthy engine.

Also check your oil level (very low oil will cause the light to flicker when going around corners)

yes, I agree our older engines run nicest with 20/50 oil.............you don't need all these thin oils...we don't live in alaska....

Erik Loye · #7 (**Post Link**) 10-03-12

The recommended oil grade in my 1970 1750 handbook is 20W-40 (which isn't commercially available any more) so I stick to 20W-50. I have used Duckhams Q250, Castrol GTX Classic and now I'm trying Millers Classic 20W-50. All seems to make no differences. My engine leaks a little from the rear crank seal on anything less than 20W-50.
I have once seen the oil warming light flicker on a hot humid summer day after a long spirited drive. I had 15W-40 oil in the sump then.
Er