TBI Throttle Body Injection discussion and questions. L03/CFI tech and other performance enhancements.

oil pressure Q?

Thread Tools
 
Search this Thread
 
Old 07-23-2008, 10:55 AM
  #1  
TGO Supporter

Thread Starter
iTrader: (1)
 
Ronny's Avatar
 
Join Date: Mar 2003
Location: wisconsin
Posts: 6,879
Likes: 0
Received 2 Likes on 2 Posts
oil pressure Q?

I see recently it is noticed it has dropped a bit when fully warmed at coolant temp of 200F. At 650 rpms I see around 17-19 lbs and at 900 rpms it increases to about 25. Steady cruise it seems normal. I notice nothing out of the ordinary as far as engine noise but it was always very smooth/quite with roller rockers.
Old 07-23-2008, 11:00 AM
  #2  
Junior Member
 
daghstdrummer's Avatar
 
Join Date: Oct 2007
Location: Astoria, N.Y.
Posts: 96
Likes: 0
Received 0 Likes on 0 Posts
Car: 1986 Z28 Camaro, 2002 Audi A4 (DD)
Engine: 350 .30 over w/bang for buck combo
Transmission: 700r4
Axle/Gears: stock for now
Re: oil pressure Q?

thats pretty normal.. when my car is warmed up totally my oil pressure drops to 15psi.. then at cruising its at 25.. i wouldn't worry bout it.. if it drops below10psi then i'd look at it and check your oil pump
Old 07-23-2008, 11:06 AM
  #3  
TGO Supporter

Thread Starter
iTrader: (1)
 
Ronny's Avatar
 
Join Date: Mar 2003
Location: wisconsin
Posts: 6,879
Likes: 0
Received 2 Likes on 2 Posts
Re: oil pressure Q?

Thanks. I recall the oil change was done with 10/30. Too warm environmentally for that weight oil. maybe i top off with straight 30.
Old 08-17-2008, 09:23 AM
  #4  
Junior Member
 
cjohn310's Avatar
 
Join Date: Jun 2008
Location: Texas
Posts: 33
Likes: 0
Received 0 Likes on 0 Posts
Car: 1992 FIREBIRD
Engine: 305
Transmission: 700R4
Re: oil pressure Q?

I notice that on my firebird I have the same problem but mine drops all the way to zero when stoped but there is no rough riding or noise. do u thing i should check the pump first or the sensor and if its the pump is there a ezyer way to get to it then pulling the engine.
Old 08-17-2008, 10:00 AM
  #5  
Senior Member
 
slow_90firebird's Avatar
 
Join Date: Jul 2007
Location: Manchester, CT + Nashua, NH
Posts: 1,461
Likes: 0
Received 1 Like on 1 Post
Car: 90 Firebird Formula
Engine: LO3
Transmission: T5
Axle/Gears: 3.08 one wheel peel
Re: oil pressure Q?

IDK why, but it seems to me that all these cars have very low oil pressure! Almost like GM messed up on something.

I change oil on alot of cars at work, and watch the oil pressure guages. Let me say, that most GM SBC V8 and the 4.3 V6 trucks, they all get at least 40psi, fully warm, and with crap 5w30 oil. Give them a little rev and it will jump even higher too!

My car keeps decent oil pressure now though. It will only drop down to the 15-20 range when I let it get close to 220* in traffic. But, once it gets that hot the oil pressure stays low even if I get some speed up and the coolant goes back down to 180*.

I was getting the same pressures as you, I ran castrol GTX 10w30. It got a little better when I switched to Rotella 15w40. I ran 3 oil changes of the rotella and it worked good. Then, just recently, autozone had a deal on 5qts of Mobil1 oil and a M1 filter for $28. I got that, but I got the 5w40 turbo-diesel truck oil, and the M1 filter for a V8 chevy van (equivalent to an ACdelco 1218).

So far, the M1 diesel truck oil has been great. I only bought it for the viscosity spread, 5w40 is perfect. It actually keeps the pressure above 30psi at idle, all the way from cold up to hot. There is only a very small area right around 180* where it goes down to 30psi, and then increases again as I get warmer.

As long as you keep moving, it will stay full pressure for a long time. Even at a hot temp, I will be pushing near 40psi cruising. It only dips down when I sit in traffic and let the oil get super hot.
Old 09-01-2008, 01:10 PM
  #6  
Member
 
ERICSCHEVY's Avatar
 
Join Date: Aug 2006
Location: Fullerton,CA
Posts: 178
Likes: 0
Received 1 Like on 1 Post
Car: 82 Camaro Z28
Engine: 305 Crossfire
Transmission: 700r4
Axle/Gears: 3:23
Re: oil pressure Q?

Originally Posted by slow_90firebird
IDK why, but it seems to me that all these cars have very low oil pressure! Almost like GM messed up on something.

I change oil on alot of cars at work, and watch the oil pressure guages. Let me say, that most GM SBC V8 and the 4.3 V6 trucks, they all get at least 40psi, fully warm, and with crap 5w30 oil. Give them a little rev and it will jump even higher too!

My car keeps decent oil pressure now though. It will only drop down to the 15-20 range when I let it get close to 220* in traffic. But, once it gets that hot the oil pressure stays low even if I get some speed up and the coolant goes back down to 180*.

I was getting the same pressures as you, I ran castrol GTX 10w30. It got a little better when I switched to Rotella 15w40. I ran 3 oil changes of the rotella and it worked good. Then, just recently, autozone had a deal on 5qts of Mobil1 oil and a M1 filter for $28. I got that, but I got the 5w40 turbo-diesel truck oil, and the M1 filter for a V8 chevy van (equivalent to an ACdelco 1218).

So far, the M1 diesel truck oil has been great. I only bought it for the viscosity spread, 5w40 is perfect. It actually keeps the pressure above 30psi at idle, all the way from cold up to hot. There is only a very small area right around 180* where it goes down to 30psi, and then increases again as I get warmer.

As long as you keep moving, it will stay full pressure for a long time. Even at a hot temp, I will be pushing near 40psi cruising. It only dips down when I sit in traffic and let the oil get super hot.
I have a 91 Camaro RS and the oil pressure is about 15-20 when first started, but after idling for a minute or so, it drops to 0-5. Is this perhaps a faulty oil pressure switch or should I just change the oil pump? If there are any other items relative to the oil pressure I should check, please let me know. Thanks.
Old 09-01-2008, 01:38 PM
  #7  
Junior Member
 
Brian21's Avatar
 
Join Date: Mar 2008
Location: So. Cal
Posts: 67
Likes: 0
Received 0 Likes on 0 Posts
Car: 1991 Pontiac Firebird
Engine: 5.0L TBI
Re: oil pressure Q?

I get about 15-18psi at idle when in traffic in this crazy California heat. At cruising speed it goes up to about 35psi. This is with Castrol GTX 5w-30.

I was always kind of worried about where my oil pressure sat at idle, but I talked to a few thirdgen enthusiasts and they all said it was pretty normal.
Old 09-01-2008, 02:56 PM
  #8  
Member
 
ERICSCHEVY's Avatar
 
Join Date: Aug 2006
Location: Fullerton,CA
Posts: 178
Likes: 0
Received 1 Like on 1 Post
Car: 82 Camaro Z28
Engine: 305 Crossfire
Transmission: 700r4
Axle/Gears: 3:23
Re: oil pressure Q?

Originally Posted by Brian21
I get about 15-18psi at idle when in traffic in this crazy California heat. At cruising speed it goes up to about 35psi. This is with Castrol GTX 5w-30.

I was always kind of worried about where my oil pressure sat at idle, but I talked to a few thirdgen enthusiasts and they all said it was pretty normal.
So is it safe to say I need to change my oil pump ?
Old 09-02-2008, 04:43 AM
  #9  
Member
 
Icarus 402001's Avatar
 
Join Date: Feb 2008
Location: SE PA.
Posts: 133
Likes: 0
Received 0 Likes on 0 Posts
Car: 92RS
Engine: 305
Transmission: 700R4
Axle/Gears: 2.73
Re: oil pressure Q?

If it's running well, with no noises, try changing the sender. OR remove the sender, put a brass nipple and tee in , reinstall sender and connect a mechanical pressure guage to check for comparison.


Originally Posted by ERICSCHEVY
So is it safe to say I need to change my oil pump ?
Old 09-02-2008, 08:39 AM
  #10  
Supreme Member
iTrader: (1)
 
UNCLE TOM's Avatar
 
Join Date: Dec 2006
Location: ms. gulf coast
Posts: 2,403
Likes: 0
Received 3 Likes on 3 Posts
Car: 91 R/S , 89 dodge p/u
Engine: L31 GM crate re-cammed , 318
Transmission: T-5 , 4 speed auto
Axle/Gears: 3.42 , ?
Re: oil pressure Q?

if its running fine change the sensor first . keep in mind even a new sensor is not the most accurate . be careful of brittle plastic connectors . oil press. is good to a point , flow is most important . too much oil press. on a street built eng. is not good . ( i said too much oil press. ) think , how does an auto tranny get its friction to move car ? it gets it from oil press. to the discs/plates . tranny fluid also is much thinner than motor oil . at too much press. oil causes friction instead of eliminating it . i'm sure my comments will bring a lot of nay sayers , but think again about auto trannys and how they work . also too much press. on a street engine will start blowing seals/gaskets . good luck .
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
83 Crossfire TA
Suspension and Chassis
36
01-03-2016 01:26 PM
angel2794
Engine Swap
11
09-08-2015 06:22 PM
Strick1
LTX and LSX
2
09-04-2015 07:11 AM
solocus
Tech / General Engine
2
09-02-2015 12:14 PM



Quick Reply: oil pressure Q?



All times are GMT -5. The time now is 11:38 PM.