Oil Pressure keeps dropping!

Old 06-28-2007, 05:29 AM
  #1  
romac_mcleod
Junior Member
SHOW GUEST
Thread Starter
 
Join Date: Apr 2004
Posts: 1
Default Oil Pressure keeps dropping!

I just rebuilt my 454 (.30 over = 468), put in a lot of new high performance parts including a melling oil pump. Got the engine in the car, started it, set the timing and let it idle for about five minutes, during this time I noticed the oil pressure gauge needle start dropping from 70 psi to 20 psi. It seems as soon as the engine gets warm the pressure starts to drop. iT HAPPENS OVER AND OVER. I changed the oil pressure gauge to see if that were the problem, gauge works fine. Put in sae 50 weight oil, pressure still drops.

SOMEBODY PLEASE TELL ME THEY HAVE HAD THIS PROBLEM BEFORE AND KNOW HOW TO FIX IT!
romac_mcleod is offline  
Old 06-28-2007, 07:32 AM
  #2  
mcracecars
Senior Member
EXPERT BUILDER
 
Join Date: Dec 2006
Posts: 272
Default

a new engine will show high pressure, 70 cold is high in my opinion.

but can you be more specific here,
Is the pressure 20 at idle HOT ?
Does the pressure increase as you rev the motor?
What is the pressure at say, 5000rpm?
Does the pressure drop as you rev the motor?
Who built the motor, could be clearence on the loose side for bearings?
mcracecars is offline  
Old 06-28-2007, 02:12 PM
  #3  
chevysb400
Junior Member
APPRENTICE
 
Join Date: Jan 2007
Posts: 13
Default

do you have a good running carb on it? it could also come from your carb putting gas in your oil thinning it out.(even with gas in your oil, it will read at an high psi on start up.)
chevysb400 is offline  
Old 06-28-2007, 05:09 PM
  #4  
havana
Junior Member
SHOW GUEST
 
Join Date: Apr 2003
Posts: 1
Default

Try installing a delco oil filter? Have seen this many times.
havana is offline  
Old 06-28-2007, 06:26 PM
  #5  
topsportsman1
Administrator
RACING JUNKIE
 
Join Date: Mar 2004
Location: Maine,USA
Posts: 1,208
Default

Are you using a FRAM filter? I have lost oil pressure like what you are talking about,and i had a FRAM filter on the engine,changed that to a NAPA and problem gone.
__________________
There Is 1 Thing Better Than Cubic Inches,,,More Of Them
topsportsman1 is offline  
Old 06-29-2007, 04:11 AM
  #6  
us7race
Senior Member
EXPERT BUILDER
 
Join Date: Aug 2005
Location: Tell City, IN
Posts: 356
Default

Mine holds about 60 idling cold and in the garage it drops to about 50 after it warms up to like 180 or so. But at the track after a pass it drops to about 40 idling until it cools for a few minutes then it is back to 50 idling..I have ran Fram and what I try to use is a Wix oil filter..
us7race is offline  
Old 06-29-2007, 07:28 AM
  #7  
cobrajet428
Member
MASTER JOURNEYMAN
 
Join Date: Jan 2007
Location: Lakeland Florida
Posts: 37
Default

A drop in oil pressure at idle as the engine heats up is normal. What you should be concern with is if the oil pressure goes back up as soon as you rev it a bit. Different engines react differently. As long as you have good pressure when not at idle and the pressure is stable and never gets below 20 psi at idle, you'll be ok. This is a common problem on engines that have grooved bearings or the oiling system has been modified by making oil passages larger. Maybe even if the crank has been cross drilled or grooved. Just to be safe, remove your oil filter and open it up to make sure you don't have metal particles in it. If you do, it's most likely babbit from your bearings. You will have to take your engine back apart and check it for clearances and damage to hard parts. JMO George
cobrajet428 is offline  
Old 12-05-2008, 10:04 AM
  #8  
mopar1962
Member
JUNIOR BUILDER
 
Join Date: Nov 2008
Posts: 87
Default

Change the oil filter :!:
mopar1962 is offline  
Old 12-05-2008, 11:26 AM
  #9  
dparker
Senior Member
RACING JUNKIE
 
Join Date: Jun 2003
Location: Hobbs, NM
Posts: 842
Default

Originally Posted by mopar1962
Change the oil filter :!:

X2
dparker is offline  
Old 12-05-2008, 03:45 PM
  #10  
fla1976
Senior Member
RACING JUNKIE
 
fla1976's Avatar
 
Join Date: Aug 2007
Posts: 1,535
Default Filter

X3 If you have a Fram, chuck it and get a Delco K&N or Wix. Read another post about the Frams.
It's under General Discussion "DON'T BUY FRAM OIL FILTERS !!!!!!!!!!!"
fla1976 is offline  

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service