Camaro_94

iTrader: (5)

I have a 94 Formula. I changed the oil over the weekend, and since then, my oil pressure has dropped. Before I changed it, it was about 30-35 at idle, and now its about 17-18. It will sometimes jump up and down 3-4psi too. What could be causing this? Is it anything serious or something I should worry about? I bought it over the summer, and this was the first oil change I have done on it. I used a high milage oil too.

Thanks,
- Mike

BigZee71

iTrader: (5)

Just use mobile one 10-30 or 5-30, your choice. Highmileage stuff is a marketing ploy.

the previouse owner could have used some heavier weight oil to thickin it up and bump up oil pressure for the sale. Who knows.

How many miles are on the engine? What temp does it run at.

Also the gauges on these cars are unreliable (So I hear). hook up as master gauge or a mechanical gauge to see whats really going on.

connexion2005

iTrader: (49)

17-18 is a bit on the low side man. What oil did you go with? I highly recommend pre-filling your oil filter with oil before you install it supply the motor with a quick burst of oil rather than air. What does it look like at cruising rpms (1,500 to 3,000)? Get a real psi gauge on the motor and monitor it there since the sending unit and gauge may be on there way out. You can get one that works fine for $10 at Harbor Freight. The location to check at is just above your oil filter and there is a small plug in its place if it's a 94 I believe. The 93 cars sending unit is actually located there...

prince_ws6

how many miles the car have?

PNYKLR-TA

iTrader: (1)

So What Is Typical Oil Pressure For Some Of You Guys For:
Cruising(1500-3000rpm's):
Cold Start:
And Wot:
After Warmed Up:

Formula Freak

My typical oil pressure according to the stock gauge is 55 at cold start,40-50 at operating temp cruising,20ish at operating temp idle,55-60 at operating temp WOT.I think those readings are within tolerances?

That is with 10w-40 valvoline premium conventional and an AC Delco filter.I had higher oil pressure with 10w-40 valvoline max life synthetic blend at operating temps,but I think that was because I overfilled it a little bit with that stuff .I went back to dino oil cause synthetic likes to seap through my gaskets

Camaro_94

iTrader: (5)

Its got 163K on it

When I'm driving around at about 1500-2000 it goes back up to 40-45.

I put 5w-30 in it, should I change it to a 10w-30?

PNYKLR-TA

iTrader: (1)

I Went To 10w 40 And My Pressure Did Go Up About 5-10 Psi Per Each Condition. The 5w- 40 Is Just Too Light For Phoenix Driving It Gets Effin Hott Here!

Camaro_94

iTrader: (5)

So if I went up to a thicker oil, would it solve or cover up the problem? Or is my problem simply that i'm just using too thin of a oil?

Thanks,
- Mike

PNYKLR-TA

iTrader: (1)

WELL I WOULDNT SAY IT IS THE ENTIRE PROBLEM, BUT A THICKER OIL WILL HELP.

ALSO JUST FOR REFERENCE MY MECHANIC TOLD ME A SAFE WAY TO CHECK YOUR OIL PRESSURE IS TO MAKE SURE YOU HAVE 1 PSI OF OIL PRESSURE PER 100 RPMS.

SO AT SAY 800RPMS YOU SHOULD HAVE NEAR 8 PSI OF OIL PRESSURE.

IMgettingLS1

i use valvoline synthetic 5-30
35-40lbs idle crusing 1800 is about 45-50 WOT is 60

Formula350

iTrader: (3)

Man, I'm surprised no Veterans have chimed in. 15-20 at warm idle is NORMAL for a stock LT1. Just like 225-235F for running temperature (which is fan1 turn on, fan2 turn on temps, respectively).

So don't worry about that oil pressure Lots of people here prefer the European 0W-20 if they can find it. Everything I thought I knew about oil weights and those numbers, went out the window when I came here heh.

Camaro_94

iTrader: (5)

Thats good to hear! Thanks for the info. What could be causing the oil pressure gauge to sometimes jump up and down 3-4psi though?


- Mike

sweet-94z28

iTrader: (30)

I would try a mechanical gauge

Formula350

iTrader: (3)

Sensor or gauge going out would be my guess. Mine does it too, but it's more like 10psi and it's clearly a signal problem and not a motor issue.

PNYKLR-TA

iTrader: (1)

holy hell you better hope thats a sensor issue 10 psi jumps haha!

but in all seriousness mine does jump around too and i always wondered if it was bad, but now i guess i know its all gravy! haha and mine jumps like 5-6 psi pretty regularily.

1badzee

iTrader: (12)

Mine idles a little above 75psi on cold startup, idles at around 28psi after driving it for like an hour, 50psi cruising (when warm), and a bit above 75psi (when warm) at WOT. I use Royal Purple 10w30. I guess you could say I have a healthy engine

Formula350

iTrader: (3)

Yea, I'm 98% sure that my oil pressure jumping is not the actual pressure jumping, just my gauge or sensor being a bastard. Oddly it really only does it when it's idling, when I'm driving it doesn't flicker any *shrug*.

1badzee

iTrader: (12)

Check to see if the wire hasnt been burnt by the headers, but at idle, are your RPMs steady? Mine flickers sometimes too when it misfires, the rpms drop an d so does the oil pressure

Formula350

iTrader: (3)

If you're asking me, I don't have headers. 93's oil pressure sender is down by the oil filter though, unlike 94+ where it's behind the intake (har har!).My RPMs only move around 50RPMs, and that's all the small misfire. Idle smoothed out loads though when I removed the AIR heh. Mine's "flicker" is like 15psi, enough to really register on the gauge and catch your attention, and being into electronics I know that it's a faulty signal or gauge. Not sure which to believe though lol My coolant temp gauge is shot, for the most part, only works when it wants and even then it reads about 40F too low! I keep my scanner in my car and every so often I'll check to see what the temp is at, but it's always fine, around 190F.