Low oil psi! Wierd issue!
03-13-2018, 10:36 PM
#1
Low oil psi! Wierd issue! Hey i got a 5.3 tht i swapped for a customer into a 88 monte carlo. Motor runs great, with no knocking or lifter tick. Problem is with cold oil, pressure is around the normal 40psi. Once started i can connect hptuners and watch the oil psi drop 1psi every minute. After engines warm and ran for 15mins or so it get to around 10psi if not lower. Usually start hearing lifters ticking by thin.
Today i installed a new oil pump, checked pickup tube clearance, installed new o ring, and a new cam retainer plate. I also pulled cam and no cam bearings pulled out or looked spun. Put it all back together same thing. Ive never had one act like this. They are usually either knocking or no psi at all! This one sounds and runs fine.
I pulled engine tonight and pulled each main cap and rod cap. Every bearing looked normal. None spun, no heat marks, looked factory untouched. No metal in oil at all. We are using the holley retrofit pan which i figured was the issue. But i dont see how it could be. Also checked barbell, it looked ok.
I have another longblock 5.3 im swapping in its place tomorrow. We Was running castrol 10w 30 oil with a boss filter. Im leaning toward bad cam bearings. Your thoughts?
Today i installed a new oil pump, checked pickup tube clearance, installed new o ring, and a new cam retainer plate. I also pulled cam and no cam bearings pulled out or looked spun. Put it all back together same thing. Ive never had one act like this. They are usually either knocking or no psi at all! This one sounds and runs fine.
I pulled engine tonight and pulled each main cap and rod cap. Every bearing looked normal. None spun, no heat marks, looked factory untouched. No metal in oil at all. We are using the holley retrofit pan which i figured was the issue. But i dont see how it could be. Also checked barbell, it looked ok.
I have another longblock 5.3 im swapping in its place tomorrow. We Was running castrol 10w 30 oil with a boss filter. Im leaning toward bad cam bearings. Your thoughts?
03-13-2018, 10:46 PM
#2
TECH Senior Member
Bad sender, won't register low pressures as it warms up.
03-14-2018, 09:51 AM
#4
Did you check the barbell and the cam retainer plate? Those are two areas that can cause large oil leaks. What are your bearing clearances and what weight oil are you running?
03-14-2018, 11:48 AM
#6
Hey i got a 5.3 tht i swapped for a customer into a 88 monte carlo. Motor runs great, with no knocking or lifter tick. Problem is with cold oil, pressure is around the normal 40psi. Once started i can connect hptuners and watch the oil psi drop 1psi every minute. After engines warm and ran for 15mins or so it get to around 10psi if not lower. Usually start hearing lifters ticking by thin.
Today i installed a new oil pump, checked pickup tube clearance, installed new o ring, and a new cam retainer plate. I also pulled cam and no cam bearings pulled out or looked spun. Put it all back together same thing. Ive never had one act like this. They are usually either knocking or no psi at all! This one sounds and runs fine.
I pulled engine tonight and pulled each main cap and rod cap. Every bearing looked normal. None spun, no heat marks, looked factory untouched. No metal in oil at all. We are using the holley retrofit pan which i figured was the issue. But i dont see how it could be. Also checked barbell, it looked ok.
I have another longblock 5.3 im swapping in its place tomorrow. We Was running castrol 10w 30 oil with a boss filter. Im leaning toward bad cam bearings. Your thoughts?
Today i installed a new oil pump, checked pickup tube clearance, installed new o ring, and a new cam retainer plate. I also pulled cam and no cam bearings pulled out or looked spun. Put it all back together same thing. Ive never had one act like this. They are usually either knocking or no psi at all! This one sounds and runs fine.
I pulled engine tonight and pulled each main cap and rod cap. Every bearing looked normal. None spun, no heat marks, looked factory untouched. No metal in oil at all. We are using the holley retrofit pan which i figured was the issue. But i dont see how it could be. Also checked barbell, it looked ok.
I have another longblock 5.3 im swapping in its place tomorrow. We Was running castrol 10w 30 oil with a boss filter. Im leaning toward bad cam bearings. Your thoughts?
03-14-2018, 07:42 PM
#7
Well we installed another 5.3 today. Started up had 45psi less than 5 mins was down to hardly anything with lifter tick. We installed the holley pan setup on this engine as well. Im leaning toward pickup tube issue. I measured it before install and had around 3/8" clearance. Imma pull it tomorrow and playdoe the pickup clearance. Ill report back.
Leaning toward just removing the holley pan and installing a truck pan. The customer purchased the holley pan for the swap. But he may have no choice but to run without it. Better than eating bearings any day!!
Leaning toward just removing the holley pan and installing a truck pan. The customer purchased the holley pan for the swap. But he may have no choice but to run without it. Better than eating bearings any day!!
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03-14-2018, 09:10 PM
#9
ModSquad
iTrader: (6)
I’ve ran the Holley pan on my last 2 builds for myself, with great results.
Almost sounds like your oil is heating up badly, which would thin it out a lot, but I don’t see how this is happening with 2 separate engines.
Almost sounds like your oil is heating up badly, which would thin it out a lot, but I don’t see how this is happening with 2 separate engines.
03-14-2018, 09:42 PM
#10
Exactly. 2 seperate motors only thing being the same was the holley pan setup. I originally didnt install the holley setup on the first engine. Customer installed it and really doesnt know any mechanical know how. He could have buggered something. But imma change to a fresh oil and filter tomorrow and see what happins. If no fix thin im pulling pan and having a look at the pickup tube. I pulled pan and installed 2 seperate o rings without any change on the last engine. Been i mess with figuring this setup out. Will be a new learning process to figure it out.
03-14-2018, 10:17 PM
#11
Well we installed another 5.3 today. Started up had 45psi less than 5 mins was down to hardly anything with lifter tick. We installed the holley pan setup on this engine as well. Im leaning toward pickup tube issue. I measured it before install and had around 3/8" clearance. Imma pull it tomorrow and playdoe the pickup clearance. Ill report back.
Leaning toward just removing the holley pan and installing a truck pan. The customer purchased the holley pan for the swap. But he may have no choice but to run without it. Better than eating bearings any day!!
Leaning toward just removing the holley pan and installing a truck pan. The customer purchased the holley pan for the swap. But he may have no choice but to run without it. Better than eating bearings any day!!
03-15-2018, 03:19 PM
#12
Ok this is what we got. Changed oil and filter. Filter had trash from other original engine. Oil psi went to 40 psi steady at idle.
Took it for a good test drive psi dropped after 2 hard runs. I think its draining the holley pan dry on a full throttle run. Pulled pan everything looked good.
Installed a truck pan and took it for a few runs. Oil psi maintained around 40psi at idle. Pressure never fell off at all. I dont know whats up with the holley setup but its not going back on. Pan was the issue all along. Probably what ended up messing the other motor up. It almost got the second motor. But everything seems to be good to go now!
Took it for a good test drive psi dropped after 2 hard runs. I think its draining the holley pan dry on a full throttle run. Pulled pan everything looked good.
Installed a truck pan and took it for a few runs. Oil psi maintained around 40psi at idle. Pressure never fell off at all. I dont know whats up with the holley setup but its not going back on. Pan was the issue all along. Probably what ended up messing the other motor up. It almost got the second motor. But everything seems to be good to go now!
03-15-2018, 06:09 PM
#14
TECH Senior Member
How hard were you running the engine when the pressure would drop? There are scores of LS engines running non-truck pans without oiling problems. How was yours different?
03-15-2018, 08:56 PM
#15
ModSquad
iTrader: (6)
Glad it’s working out for you. How many quarts did you put in the engine with the Holley unit?
What’s odd about this is the Holley pan usually finds its way into muscle car type setups, which are often set up to run auto cross, or other high rpm competitive events. I would personally lean more toward the Holley pickup having an issue.
Irrelevant now. Glad you got it going!
What’s odd about this is the Holley pan usually finds its way into muscle car type setups, which are often set up to run auto cross, or other high rpm competitive events. I would personally lean more toward the Holley pickup having an issue.
Irrelevant now. Glad you got it going!
03-15-2018, 09:37 PM
#16
2 runs from a dig. 1st, 2nd, 3rd.
It very well could have been a pickup issue. It looked perfectly fine after pulling it. Original holley o ring looked fine. Oil pressure basicly went from a steady 40 psi before 2 runs to around 15pai or less and never recovered. Shut engine down let it sit for a couple minutes and oil psi would be back to 40psi at idle. Definately not what u want in a drag app with pressure falling off.
After looking everything over, it looks as if the internal pan baffle was to close to the pan floor. Everything was installed as it came from holley. Makes since for it to suck sump dry. I thought about modifieing it but i just dont have the time and patience to keep messing with it. Customer is happy with everything now.
It very well could have been a pickup issue. It looked perfectly fine after pulling it. Original holley o ring looked fine. Oil pressure basicly went from a steady 40 psi before 2 runs to around 15pai or less and never recovered. Shut engine down let it sit for a couple minutes and oil psi would be back to 40psi at idle. Definately not what u want in a drag app with pressure falling off.
After looking everything over, it looks as if the internal pan baffle was to close to the pan floor. Everything was installed as it came from holley. Makes since for it to suck sump dry. I thought about modifieing it but i just dont have the time and patience to keep messing with it. Customer is happy with everything now.
