How to Check Oil pressure, on the engine stand
#1
TECH Resident
Thread Starter
How to Check Oil pressure, on the engine stand
If you have ever installed a LS motor and had oil pressure problems, you know it is not fun. The usual suspects are: O ring on the pickup tube, metal plug in the front of the block, barbell in the back, and my favorite; the pickup is too low in the pan. Here is a simple solution that is worth trying. With the short block together, oil filter on, 5 qts of oil in the pan, lifters installed, and no rockers or sparkplugs. Hook up a mechanical gauge, put a breaker bar on the crank and crank it over as fast as you can. Link to oil pressure video.
http://www.youtube.com/watch?v=YT-yCLo2dos
In the video it gets oil pressure really quick because we tried it a few minutes before. When the motor was dry, it took at least 30 or 40 cranks to get pressure. All of that noise is from the spark plug holes.
I would never install a motor without trying this first.
http://www.youtube.com/watch?v=YT-yCLo2dos
In the video it gets oil pressure really quick because we tried it a few minutes before. When the motor was dry, it took at least 30 or 40 cranks to get pressure. All of that noise is from the spark plug holes.
I would never install a motor without trying this first.
#2
TECH Resident
If you have ever installed a LS motor and had oil pressure problems, you know it is not fun. The usual suspects are: O ring on the pickup tube, metal plug in the front of the block, barbell in the back, and my favorite; the pickup is too low in the pan. Here is a simple solution that is worth trying. With the short block together, oil filter on, 5 qts of oil in the pan, lifters installed, and no rockers or sparkplugs. Hook up a mechanical gauge, put a breaker bar on the crank and crank it over as fast as you can. Link to oil pressure video.
http://www.youtube.com/watch?v=YT-yCLo2dos
In the video it gets oil pressure really quick because we tried it a few minutes before. When the motor was dry, it took at least 30 or 40 cranks to get pressure. All of that noise is from the spark plug holes.
I would never install a motor without trying this first.
http://www.youtube.com/watch?v=YT-yCLo2dos
In the video it gets oil pressure really quick because we tried it a few minutes before. When the motor was dry, it took at least 30 or 40 cranks to get pressure. All of that noise is from the spark plug holes.
I would never install a motor without trying this first.
#4
TECH Resident
Thread Starter
I was happy with 40 psi cranking by hand. I can't explain why it stops at 40. When I try to crank faster, it stays on 40. LS6 ported pump with shim.
Starter will do the same trick, if you have the right battery cables.
Starter will do the same trick, if you have the right battery cables.
#5
TECH Resident
The relief valve probably operates at 38-40psi with the shim, limiting the pressure if you are still ramping up the rpm.
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#8
#9
TECH Resident
Thread Starter
The first time that I tried this was with the new motor, oil passages dry, filter full. With the oil pressure gauge in the back top of the block I cranked for 15 revolutions, nothing, cranked another 15, nothing. I pulled the plug on the side of the block, next to the oil pump, oil ran out. Put the plug in, cranked another 15, Got Pressure, then I could hear it gurgling inside the motor. The oil has to fill the passage from the pump all the way back to the filter, then up to the top, and fill both passages by the lifters before you will have any pressure, that's a lot of oil. Keep cranking, from my experience, it took 45 turns the first time to get pressure. We shot the video, AFTER it had been pressured one time.