Oil pressure sending unit ??

[gator]

Hi all .. My oil pressure shows low on the guage. I dont think the oil pressure is actualy low. The oil level is fine. I have replaced the sending unit and (70$ latter) it made no difference. Should I put in thicker oil and see if that makes a difference. Is there a oil pressure tester I could try to see what the pressure actualy is? I know these motore have a very good oil pump. I dont really know the milege of this motor as the speedo has been changed. It does not burn oil and runs very well. It pulls hard up hills and sounds great .. no lifter noise even.

Any help or comment would be great

Thanks and Cheers Bruce Ü

[Virto]

Did you buy a new factory unit? Aftermarket units are notoriously crappy, and you can grab a factory unit from CoutesyNissan for like $55 US.

You might also have a faulty new unit. Disconnect the lead from the sender and ground it to the chassis. Turn the key to ON and the gauge might rise to the top slowly. This indicates a faulty sender.

Could also be a broken gauge. It's been known to happen.

[seerex]

try and clean the inside connection the one in the engine compartment , wouldn't hurt to see if its really gummed up

[gator]

thanks guys .. I bought the unti from Nissan .. the lead to the unit is clean like new and making good contact .. but I will check it again.

I will also try the test Virto suggested.

Cheers ..Bruce

[DatsunZsRule]

What weight oil are you using?

[260Zed]

Are you sure there is a problem? I mean my oil pressure reads fairly low (just above lower mark) when at idle and V low speeds, and will only go to the high mark when I'm really giving it the boot.

Does the guage move at all? Also check sender as earlier described.

Good luck

Luke

[gator]

I am using 10-30 oil. I am not sure there is a problem at all. I feel it would be nice to see the pressure abit higher. The guage does move. It reads higher when car is cold and when revs are higher.

[DatsunZsRule]

10W30 is also what I use. I think thicker oil is a mistake in my opinion if you live in cooler weather. Some use that 20W50 weight which is way over kill in cooler climates. The 10W30 will reach the upper half of the motor faster and will provide much better lubrication. Now if you live in areas with 100+ degree heat than 20W50 is a must.

It is normal to have higher pressure when cold and when your reving the motor. It will always read lower at idle. Sounds like it's working correctly to me.

[BillD]

My 240z had low oil pressure when running and almost no oil pressure at idle. Everything was running fine, but I switched the oil pump to a higher pressure/volume turbo unit for the 280z turbo engines. This change over brought the oil pressure to the 10psi/1000rpm level that is within my comfort level and it didn't take a lot of time or money.

[sblake01]

I've got turbo oil pumps in both of my cars. At the junkyards in most cases they take all the rest of the turbo stuff but leave the oil pump. That's where I got mine.

[ZSaint]

I know that these electrical units do not react very quickly to pressure changes. If you have access to a mechanical guage, try plumbing it into the block and check the pressure. As long as you have 30#-40# pressure, your engine will run forever. Now if you tweak the engine and have high rpm needs, now that is another question. 25# oil pressure on the freeway is plenty of pressure to maintain oil viscosity.

[2003z]

I have been told that to solve the gauge problem, use a sender from a fairlady roadster. Supposedly MSA sells it and they will know what you need if you call them.