does anybody on here have oil pressure issues? im assuming its the sensor or gauge itself... but at idle im at 60



and under a little throttle, it spikes at 90 (the highest it goes)

 

im ASSUMING bad gauge/sensor or whatever.... have a pressure tester on the way.... should have had one a while ago........

any thoughts???

 

If that's cold-idle....your gauge and your sender are fine, I'd look for problems with the bypass valve in your oil pump...

If that's hot-idle.... I'd clean the connection at the sender first.

 

yeah, its cold idle... when hot, its usually around 40-50ish... but under load, spikes back up to around 90 again.

 

It is normal for cold oil pressure to be quite a bit higher than hot oil pressure due to the viscosity change of the oil. And we don't mean hot as in "coolant temperature at mid-range." We're talking 15-20 minutes of loaded operation after that -- it takes time for the oil to come up to temperature.

 

yeah, i understand that... ive just never seen pressure jump so high under load on any other vehicles... not even my other miata.

its within normal limits at idle after warmup, but a little throttle changes that quickly

 

All else being equal, assuming your gauge is accurate and your engine is in good health, we expect the oil pressure to behave roughly as follows:

When cold:
Idle = 30-50 PSI
3,00 RPM = 60-70 PSI

When warm:
Idle = 20-30 PSI
3,000 RPM = 60 PSI.

These numbers are not from the manual, just my personal experience.

If the warm oil pressure exceeds 60 PSI by a great amount, this may be indicative that the oil pressure control valve inside the oil pump is stuck closed. It's harder to make accurate judgements about cold oil pressure, simply because it's thick enough to out-flow the valve.

 

well... im probably gonna switch over the cluster from my other NA, and see if its the same... then, go to the sender next, then the valve after that, if its not one of those 2...

i wouldnt doubt that the gauge is fucked though, because the tach is about 1k higher than actual RPM's at ALL times... idk what this guy did... didnt care too much for the last few years, because it was just a DD/toy, but i wanna get it all straight, and all these little quirks are pissing me off... lol

 

just get one of these:

 

hah... i should... i would rock the **** out of that cluster.... lol

 

alright, pulled out the cluster to work on the Tach, and noticed a light i dont recognize. it does NOT come on when i turn key to ACC on either one of my miatas.

What is the indicator above the fuel gauge on the NA miatas(little square light)? airbag, or abs or something???

 

Hardtop defroster would be my guess.

 

well.. that would make sense... since as much as i would love to have one, neither of my cars do... haha
thanks!

 

Quite possible.

There have been a couple of different NA gauge clusters. On my '90, for instance, there is no indicator space in that position. So it could well be the HT defroster, which was not available in that year. (My gauge cluster also lacks the cutout for the washer fluid light, as ABS wasn't available in '90. But that light goes in the center, between the speedo and tach.)

 

i have the connectors for the rear defroster, so i assume it was available in '92. my other miata is a 90... does NOT have the connectors.. but still has an indicator space. Im obviously not the original owner of THAT miata either, so i think the cluster may have been replaced at one time, with one that has the same indicator. i just looked around online, and some clusters have them, and some dont.

 

The defogger wiring was added in late '91 for the '92 model year, I'm not sure when the number of idiot-light positions in the cluster was increased.

Here's what my '90 instrument panel looks like:




You'll note that it's missing both the rectangular light above the fuel gauge (rear defogger) as well as the two round lights to the left and right of the central square panel (ABS and washer fluid.)


Sidebar: if you do a Google Images search for Miata Instrument Cluster, this guy shows up:

 

thats because that guy is a Bawsss.... lol

yup, thats what alot of the clusters i found online looked like. thats why my little rectangle cornfused me. i would almost prefer that cluster... although, being that none of those extra indicators are lit up, it doesnt really bother me too much.

Thanks man!!