Reading Oil pressure gauge on 90 Nissan 300ZX
Etop Udoh
How do you read the oil pressure gauge on on 90 Nissan 300zx ?
what is a good reading ?
what is a low reading ?
what is a not so good reading, and when should you read it ?
what do you readings actually mean ?
Thanks..
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Etop Udoh sdru...@yahoo.com http://www.geocities.com/sdruid11
Clamstrippe Fecadunker
> On Sat, 01 Nov 2008 17:24:23 -0500, Etop Udoh <sdru...@bellsouth.net>
> wrote:
>
>>
>> How do you read the oil pressure gauge on on 90 Nissan 300zx ?
>> what is a good reading ?
>> what is a low reading ?
>> what is a not so good reading, and when should you read it ?
>> what do you readings actually mean ?
>> Thanks..
>
> I don't have a '90 300zx in front of me at the moment, but most
> engineers design gauges so that "normal" is at the halfway point. A
> little high or low is OK, but a big variation is cause for concern.
>
> Low oil pressure readings can mean a worm engine or a weak oil pump.
> High ratings can mean clogged passages in the engine. All this
> assuming you've changed the oil relatively recently and put in a
> proper filter.
>
> There may also be more specific things a 300zx gauge tells you - for
> example, a reading that varies significantly with engines RPM
> indicates wear - but what specific wear is typical in that motor would
> be better found by seeking out a web forum specific to Z cars.
I agree with the "middle of the range" statement, however early Z cars
are notorious for very low readings at idle. I don't know if the 90's suffered
from this but I doubt it. either way, starting from idle, the pressure should
rise somewhat with RPM until it reaches a peak value, then stay constant
with more RPM.
if your gauge scale is in PSI the rule of thumb attributed to Smokey Yunick
is 10 psi per 1000 rpm as a ballpark figure. if you have less than 60 PSI
at 6000 RPM for example, there may be a problem. if the pressure is
more than 100 PSI at any time, there also may be a problem (you don't want
your oil filter to explode...)
the dashboard gauge can be no more accurate than the sending unit, so we
are assuming it is working within design tolerance. if you really want to know
the pressure precisely you would need to temporarily replace the sending unit
with a mechanical gauge of known accuracy.
these and the comments above assume your engine contains oil of the
specification found in the owner's manual and that the engine is warmed
to normal operating temperature.
