Low Oil Pressure Question
05-07-2005, 10:41 PM
#1
Drifting
Thread Starter
Low Oil Pressure Question
When I start her cold my gauge reads pretty puny...I believe the needle goes to about the first line in the gauge- maybe 20lbs. max and then goes down from there when the engine gets warmer until it barely reads anything . I replaced the oil pressure sensor and it did not make a difference. I pulled the wire off the sensor to see what the gauge does when it is unplugged, the needle went all the way to the right--so I thing that the gauge is OK.
What else could contribute to low oil pressure? What would be the next things to look for and test?
What else could contribute to low oil pressure? What would be the next things to look for and test?
05-07-2005, 10:45 PM
#2
Race Director
Originally Posted by 79vetter
When I start her cold my gauge reads pretty puny...I believe the needle goes to about the first line in the gauge- maybe 20lbs. max and then goes down from there when the engine gets warmer until it barely reads anything . I replaced the oil pressure sensor and it did not make a difference. I pulled the wire off the sensor to see what the gauge does when it is unplugged, the needle went all the way to the right--so I thing that the gauge is OK.
What else could contribute to low oil pressure? What would be the next things to look for and test?
What else could contribute to low oil pressure? What would be the next things to look for and test?
hook up a mechanical oil gauge to this engine and see waht your results are....could be bad sender unit could be a worn engine or bad oil pump (i doubt this)
05-08-2005, 12:31 AM
#3
Le Mans Master
I had this problem a few years ago when my Holley leaked - had to rebuild the bottom end as the bearings were shot, machined the crank. Luckilly the top end was fine which was surprise.
05-08-2005, 11:23 AM
#4
Well, low oil pressure is a first sign of engine wear, especially bearing wear! How many miles are on the engine?? I agree I would try another guage to check pressure, just to be sure.
05-08-2005, 11:50 AM
#5
I agree you need to check with a mechanical gauge. Even if it shows low there I would check out the oil pump before I tear the engine down. I have had more than one sbc with a stuck relief valve in the oil pump.
bob
bob
05-08-2005, 07:52 PM
#6
Drifting
Thread Starter
Well, I hooked up a mechanical gauge and it ran 20psi when started...
Not sure if I have a problem or not---would a compression test verify if I have a problem?
Not sure if I have a problem or not---would a compression test verify if I have a problem?
05-08-2005, 08:10 PM
#7
Safety Car
A compression test will tell you the condition of the top end, rings, valves etc, if it is low it would only mean that besides the lower end being worn out the rest of the engine is gonna be toast also..Some old timers usta try a heavier weight oil to see if that improves the reading on the gauge,,, Good luck,, how many miles on the engine,,,,,,,Peace,,,Craig 
05-08-2005, 08:23 PM
#8
Drifting
Thread Starter
Whoops , forgot to mention : Engine mileage is unknown. I have one document that says around 120K but I don't know any history on the engine as it is new to me....
05-09-2005, 07:28 AM
#9
I do know this, if you even think there is a remote possibility that the 79 has 120K. I would rebuild the whole shootin match! If I am gonna go through the trouble of removing the oil pan, she would get rebuilt. A compression test will give you more info, but I would go ahead and get the parts list together. The unknown just drives me nuts! The compression test, if bad it is rings or the heads. When the head or heads are removed you can tell in a second if it needs gone through. If your fingernail catches on the upper cylinder wall, she needs it!