Firebird Nation banner
1 - 17 of 17 Posts

·
Registered
1995 firebird trans am 5.7 lt1
Joined
·
46 Posts
Discussion Starter · #1 ·
hey so i’m having oil pressure issues when my car begins to warm up, when i’m in higher gears i have decent oil pressure i feel it’s a little low but when i’m in first and reverse my oil pressure goes all the way down to zero idk what to do please if you need more information let me know what to say so you can help thanks in advance
 

·
Registered
Joined
·
41 Posts
I'd check simple things first. Is your oil level correct? How many miles are on your oil filter? Sometimes when oil filters become clogged enough to bypass the filter media, oil flow becomes reduced and pressure can drop.
 

·
Administrator
Joined
·
15,264 Posts
What is the gauge pressure reading at COLD idle (and what is your idle RPM.?) ….. at WARM idle? ….pressure at 2,000 RPM? ….. pressure at 4,000 RPM?

When the oil pressure drops to “zero” does the check gauges light come on? The light should come on when the pressure drops below 6 PSI.

What viscosity oil are you using?

How many miles on the engine?

It's normal for pressure to be “low” at low RPM, and to increase with higher RPM. In reverse, your engine would be at lower RPM = low oil pressure. But in 1st gear the vehicle is usually accelerating at higher RPM, so it would be unusual for the oil pressure to be low in both “first and reverse”.
 

·
Registered
1995 firebird trans am 5.7 lt1
Joined
·
46 Posts
Discussion Starter · #4 ·
I'd check simple things first. Is your oil level correct? How many miles are on your oil filter? Sometimes when oil filters become clogged enough to bypass the filter media, oil flow becomes reduced and pressure can drop.
i just did an oil change thinking the same as what you thought
 

·
Registered
1995 firebird trans am 5.7 lt1
Joined
·
46 Posts
Discussion Starter · #5 ·
What is the gauge pressure reading at COLD idle (and what is your idle RPM.?) ….. at WARM idle? ….pressure at 2,000 RPM? ….. pressure at 4,000 RPM?

When the oil pressure drops to “zero” does the check gauges light come on? The light should come on when the pressure drops below 6 PSI.

What viscosity oil are you using?

How many miles on the engine?

It's normal for pressure to be “low” at low RPM, and to increase with higher RPM. In reverse, your engine would be at lower RPM = low oil pressure. But in 1st gear the vehicle is usually accelerating at higher RPM, so it would be unusual for the oil pressure to be low in both “first and reverse”.
idk if this is weird to ask but can you give me a phone number to text i have some videos of me reving it cold and warm with me showing the gauge and my oil is the recommended 5w-30 and my engine is a crate engine with 33k miles on it and yes the check gauge light does pop up
 

·
Administrator
Joined
·
15,264 Posts
Post the video here.
 

·
Administrator
Joined
·
15,264 Posts
 

·
Administrator
Joined
·
15,264 Posts
Are you sure the engine has a stock oil pump? The stock pump has a relief spring in it to limit the max pressure to 60 PSI. On cold start, revving the engine exceeds that. Modified engines sometimes use an 80 PSI relief spring.

Are you sure the oil is a multi-viscosity 5W-30 (or even 10w-30?)? The pressure seems wayyyy too sensitive to temperature. At cold start it's producing 50 PSI at idle. That drops to 20+ PSI at 180-degF and just about into the red (6 PSI) at 210-degF.

Has the gauge always acted like this? Or is this something recent?
 

·
Registered
1995 firebird trans am 5.7 lt1
Joined
·
46 Posts
Discussion Starter · #12 · (Edited)
Are you sure the engine has a stock oil pump? The stock pump has a relief spring in it to limit the max pressure to 60 PSI. On cold start, revving the engine exceeds that. Modified engines sometimes use an 80 PSI relief spring.

Are you sure the oil is a multi-viscosity 5W-30 (or even 10w-30?)? The pressure seems wayyyy too sensitive to temperature. At cold start it's producing 50 PSI at idle. That drops to 20+ PSI at 180-degF and just about into the red (6 PSI) at 210-degF.

Has the gauge always acted like this? Or is this something recent?
from what he’s saying it is stock and i’m running 5w-30 and no it hasn’t this is a brand new issue with this gauge
 

·
Registered
1995 firebird trans am 5.7 lt1
Joined
·
46 Posts
Discussion Starter · #13 ·
Are you sure the engine has a stock oil pump? The stock pump has a relief spring in it to limit the max pressure to 60 PSI. On cold start, revving the engine exceeds that. Modified engines sometimes use an 80 PSI relief spring.

Are you sure the oil is a multi-viscosity 5W-30 (or even 10w-30?)? The pressure seems wayyyy too sensitive to temperature. At cold start it's producing 50 PSI at idle. That drops to 20+ PSI at 180-degF and just about into the red (6 PSI) at 210-degF.

Has the gauge always acted like this? Or is this something recent?
could it be my oil pressure sender or my gauge or my oil pump or do you think it’s something completely different
 

·
Administrator
Joined
·
15,264 Posts
A faulty oil pressure sensor is a possibility. Or an issue with the single wire and connector. You mentioned that the problem occurs when in reverse. Maybe the engine is torquing enough to cause the wire or sender to hit something under the cowl.

Best thing to do is hook up a known accurate mechanical pressure gauge and see if it exhibits the same odd behavior as the dash gauge. There is an available port for installing a mechanical gauge, in the block right above the oil filter:


That's where the 1993 and early production 1994 models had the pressure sensor located. The one on the back of the block is a bit difficult to access:

 

·
Registered
1995 firebird trans am 5.7 lt1
Joined
·
46 Posts
Discussion Starter · #15 ·
A faulty oil pressure sensor is a possibility. Or an issue with the single wire and connector. You mentioned that the problem occurs when in reverse. Maybe the engine is torquing enough to cause the wire or sender to hit something under the cowl.

Best thing to do is hook up a known accurate mechanical pressure gauge and see if it exhibits the same odd behavior as the dash gauge. There is an available port for installing a mechanical gauge, in the block right above the oil filter:


That's where the 1993 and early production 1994 models had the pressure sensor located. The one on the back of the block is a bit difficult to access:

can i just replace the oil pressure sensor an go from there ? if so how would i go about fixing that
 

·
Administrator
Joined
·
15,264 Posts
If you prefer playing “parts replacement roulette“ rather than doing some diagnostics, it's up to you.
 

·
Registered
1994, Firebird Formula, LT1, 5.7
Joined
·
1 Posts
Hello,
I am having the same problem. Oil pressure is good on start up, but then it drops when the temp reaches around 220. The low oil pressure is causing the "Check Gauges" warning light to come on and the Oil pressure gauge reads almost 0.
Was just wondering if you found out what the problem was with your car? If so can you please let me know what it was. I Would truly appreciate it.
Thanks,
Jheels
 
1 - 17 of 17 Posts
Top