Oil pressure

[Gee]

My oil pressure drops right off when I pull up at the lights (almost down to the bottom of the guage) but then builds back up to 1/2 way when moving along. Is this right with a zed or is something stuffed??? help!!!!

G

[Z Kid]

Just thinking, its probably one of two things, the gauge and or sender is cactus, or the motor is low on oil, not sure about the Z's (never had one on the road) but with my landrover, the gauge going down on braking was an indication that the oil was surging forwards, starving the oil pump, and decreasing oil pressure. Its probably not anything too major, when i had the Z motor runnin just to check it out, i had an eppileptic tacho, all over the shop.

Good Luck

[DakotaZ]

90% chance that it's the oil pressure sender unit. Mine was, it's a common problem.

[Gav240z]

Yes it is a common problem that the sender unit on the Z screws up but it could also be one of the bearings for the crankshaft.

Replace the sender and if no luck try a good guage aswell. If this does not help get it checked with an external tester otherwise you could end up screwing the head on the engine.

Gav,

[CNIXZGO]

oil sending unit. I just replaced mine last week and it now reads constant peressure whether im idling or not. Mine was also leaking oil profusely as the insides go bad in it. It's a very easy replacement. I bought the new one at my local parts store for 39 bucks rather than pay Nissan 50 plus, I just wanted it to stop leaking!!!! I always check my oil anyway!

[Gee]

I don't think its the crank bearing as I can't here any rumble from the bottom end. The oil is also new and on the full line. I will check the sender.. seems strange that it only plays funny buggers when I idle though :classic:

[24OZ]

G'day Gee,

I have a similar situation going and after reading up on various sites and posting q's I was also told how unreliable the sender units are.

Here are 3 simple steps so as to know for sure if it's your sender or not.

1.) With the ignition off, take the wire off the end of the sender.

2.) Ground the wire to a clean metal surface in the engine compartment.

3.) Turn the ignition to the "On" position, but don't start the car. The needle on your oil pressure gauge should rise slowly but steadily, to the top. If it does, then the sending unit is bad, and needs to be replaced.

BTW- before anyone starts thinking that I am some sort of amazing Z mechanic (I wish!) I paraphrased that from a Tech Tip I found in an old MSA Z catalogue.

Good luck in your testing and I hope it's just a bad sender. Cheap to replace.

[Daniel]

Hey George,After 30+ years of service its fails.Therefore it is unreliable? They just fill up with all the small carbon and crap.You are indeed correct on your "go to ground" test. I would just like to add that the fuel and temp can be tested in the exact same fashion on ALL cars I am aware of.In fact I have a friend that is a GM tech.On GM cars 70 thru early 90's when you switch the key on it lights a "gen" light.If that bulb burns out the car will not start!!!It's quite the war story session of the mechanics attempts to solve the problem when its just a bad light bulb!!!

[Gee]

Sounds like a good trick!

On a completely unrelated topic, has anyone ever made a complete list of zed parts which are available on other cars? i.e. doorhandles were on 1600 etc etc??? Would be awesome for us misers!!

GROFL

G