oil pressure

[timh1972]

hello i have a 93 300zx TT what should the idle oil pressure be? and when it's warm it shows less than the mark before the 60 should i be concerned? if so what would i check? thanks Tim

[Z31toZ32]

it should be around 60 cold, and when warm it should be around 10-15 at idle, around 30 city driving and about 45 highway. the stock oil pressure unit tends to go bad over time and often will end up reading 0 after it warms up.

[Ace2cool]

^^10-15 at idle is a little low, IMO. I'd like to see a very minimum 15 at idle at the least. (That's what it says in the FSM too)

[es.biggs]

FSM says you should have at least 11 psi at idle. If you have over 11 you're fine. I don't trust the stock gauge for crap. I've checked my oil pressure with a real gauge and it's around 18 or 19 at idle if I remember correctly. It should increase with RPM...your oil pump runs off of your crankshaft.

[Ace2cool]

^Good correction.

I've noticed my N/A runs higher at idle, but lower top end pressure than my TT. It usually sits around 28 psi idling, and gets up to a max of about 62.

The TT usually idles around 12-20 psi when warm, and when romping on it, can see almost 90 psi.

They both, however, fall perfectly into spec when at the idle/ 3000 rpm test.

[bartZ32tt]

Moral of the story - check it manually with a mechanical gauge. It's common for these cars to have the oil psi sender unit clogged up. Some have either bored out the hole or replaced it with a jeep sender unit to prevent this, and claim good accuracy with the stock gauge.

[Ace2cool]

^^I honestly thought about boring the hole, as the hole is absolutely TINY on the stock sending unit. Didn't know anyone had actually done it.

[Z31toZ32]

yeah i believe there is a step by step on how to drill out the hole on tt.net. however, it is kind of weird how this works, because when the stock unit goes, it will read 0 psi. if the unit is clogged, as it dies you would think it would read higher and higher with clogged hole rather than going to 0.

[timh1972]

thanks for all your answers, i feel better about mine now