ive been trying to figure out what its for, is it to indicate oil level or usage? and where should it generally be? cant believe im not even sure what its for lol...... thanks in advance

You on about this gauge on the dash? If so its for the oil pressure

yes the gauge in the dash under the rev

Oil Pressure, I think it should be just above 4 when you first start the car, then once the oil warms it should settle to below 4 on tick over and will change with the revs slightly. If you ever see it drop off to zero then stop the engine straight away! :P

thanks fellas

Yup - oil pressure indeed......

 

....And whilst wchestnutt would normally be correct in what he says; there is another possible explanation if the pressure drops to zero when driving!! The sender unit on these cars is notoriously fickle and prone to failure - so once the engine is warm and the pressure drops, stop and listen to the engine. If it still sounds OK, then it's your sender unit that has packed up. Of course, if the engine sounds like a bag of spanners, then yes, your oil pressure has dropped to critical levels so switch off right away!!

 

The OEM sender unit is the thick end of £100 sadly, so many people don't bother to replace it. JeffTT took one apart once to see why they fail - apparently the electric contacts on the section which measures normal hot oil pressure wear, as the sensor is constantly rubbing in that area; so when cold, the gauge works but once warmed up, it does not always register a reading.

 

Mike at MJP has also said this was a common Nissan problem; as that sensor is used on one or two other cars also.

 

Richard:yinyang:

Invest in a second water temp, oil temp and oil pressure. That's something everyone with a 300zx should have.

thanks, yes i do listen to the engine more than anything and if it sound different i get paranoid lol cant help it, i have asked in another tread about a ticking noise from the engine if you guys can shed more light that would be great, thanks

Invest in a second water temp, oil temp and oil pressure. That's something everyone with a 300zx should have.

 

agree 100%

i am looking at getting those in the near future :D

Possibly 60% of all Zeds I've worked with have faulty OEM oil pressure gauges.

Possibly 60% of all Zeds I've worked with have faulty OEM oil pressure gauges.

 

and the other 40% have a faulty clock:laugh: