Low oil pressure
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Low oil pressure Hey this is my first ls1 I had it mildly built a while back it was reading lower oil pressure than i woulda liked. The machinist said it would be fine less than a year later cam bearings went out. I took it back to the machinist had it rebuilt again as soon as i got it back together it was reading even less oil pressure than the first build with a high volume pump. My machinist has never touch a modern ls block before is there any kind of machining error that could be made on these to cause this issue?
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Never let anyone who has not worked on an LS motor near one...they will *** it up 'every time'.
oil pump O ring has probably been pinched allowing pressure to pass.
Use the search button...read as much as you can about the LS motor from mods to maintenance & all the pit falls the guys have come across....there are many!
All your oil pressures hot & cold, cams, heads, exhausts, manifolds etc.
You have many hours of reading ahead of you & a huge amount to digest....Goodluck
oil pump O ring has probably been pinched allowing pressure to pass.
Use the search button...read as much as you can about the LS motor from mods to maintenance & all the pit falls the guys have come across....there are many!
All your oil pressures hot & cold, cams, heads, exhausts, manifolds etc.
You have many hours of reading ahead of you & a huge amount to digest....Goodluck
what is the engine mileage and viscosity engine oil are you running?
I would suggest performing an oil pressure test. check your oil pressure at the specific RPM range according to engine model. if the oil pressure is low it is most likely the oil pump.
also make sure to remove the pick up and clean it out, sometimes it can be clogged not allowing it to suck up engine oil. once the pump is removed check the snout of the crankshaft for wear, if the snout that makes contact with the oil pump is worn that may be your cause. there is not enough contact to spin the pump since it is a rotor style pump.
hope this helps
Last edited by senor_camaro; Nov 22, 2011 at 02:12 PM.
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Thinking you need to list exactly what was done to your engine & parts used, mileage thats been done on the build, What it was like before the bearing issue & after.
As much info as possible always helps.
As much info as possible always helps.
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Verdad Gallardo I actually researched into this further, I saw that you mentioned that you had a high volume oil pump. i think that is the cause of your problem. if your using the stock pan I dont think theres enough oil in there to keep refilling the bottom end once its pumped thru. you should look into what size pan that pump is rated for, you might have to buy a higher capacity pan or maybe a remote reservoir.
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I actually researched into this further, I saw that you mentioned that you had a high volume oil pump. i think that is the cause of your problem. if your using the stock pan I dont think theres enough oil in there to keep refilling the bottom end once its pumped thru. you should look into what size pan that pump is rated for, you might have to buy a higher capacity pan or maybe a remote reservoir.
you should put the stock oil pump back on and see if your oil pressure changes.
unless your doing some hardcore racing, have a higher capacity oil pan, and dry sump your just setting your engine up for disaster. your gonna starve the bottom end and damage your engine.
what where your oil clearances?they should be on your engines build sheet from the machine shop.
Last edited by senor_camaro; Nov 23, 2011 at 12:00 PM.
No , the high volume pumps don't pump 2 times the stock pump and if it emptyed the pan the gauge would go from showing oil pressure to zero oil pressure and there would be bearing damage . sounds 2 Me like bearing clearance issues but 2 b more certain it needs 2 b checked with a mechanical oil pressure tester b-cause the electronic 1's can b unreliable .
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yea it was tested with a mechanical oil pressure testor and it matched what the gauge read i researched the pump and the only issues i found were under high rpm pulls pressure dropped. Its a pretty mild build mild cam shaved heads for a little extra compression double roller chain the machinist said the main bearings where in spec. Is it possible the new pump could be deffective ?
absolutely, its possible that the pressure relief valve is stuck open or deffective rotor. change the pump like I mentioned and you will definetley see a difference in pressure. make sure to prime the pump before installation
yeah.. o-ring is usually the most common problem. but also if the oil pickup is not seated correct and flush in the pump, it well also cause problem.
Did you check your oil pickup / tube to the bottom of the pan clearance..?.. put some clay on it and then put the pan back on. to check it. if it is too close to the bottom, it can cause problems. I have about 3/4" on mine.
I would also check the relief valves (dumb bells in the block) and valve in the pump.
Did you check your oil pickup / tube to the bottom of the pan clearance..?.. put some clay on it and then put the pan back on. to check it. if it is too close to the bottom, it can cause problems. I have about 3/4" on mine.
I would also check the relief valves (dumb bells in the block) and valve in the pump.
I would be willing to bet, since he has never done an LS motor that he doesnt know you have to "center" the cam bearings in the bore. Not just push them flush with the face of the cam bore. If you search EPIC low oil pressure thread on here you will see what im talking about.
No high volume/high pressure pump will run the pan dry of oil (especially at idle). If you are truly getting 0-10psi of oil pressure I don't even know how your engine is still running. You should be getting ~40psi warm idle with a stock pump, ~50psi if you have a ported one.
Pick up should be no more than 3/8 to 1/2 from the pan. Another thing is the pick up screen can be to restrictive. I run my stuff 1/4" and have not seen a oiling issue
I am guessing this is a alum block. The mains need no more than .002 rods can be .0024 or so.
cam bearings can be the issue but a competitent machinest should be able to handle this. Some cant even get them in straight and this will tighten the clearance up.
My engine makes 60 psi cold idle and 30 hot. The block grows a bunch and if you don't have the ability to overcome that with extra volume you will have issues
Tim
I am guessing this is a alum block. The mains need no more than .002 rods can be .0024 or so.
cam bearings can be the issue but a competitent machinest should be able to handle this. Some cant even get them in straight and this will tighten the clearance up.
My engine makes 60 psi cold idle and 30 hot. The block grows a bunch and if you don't have the ability to overcome that with extra volume you will have issues
Tim
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also they are differnet size cam bearings that help align the camshaft in its bore i work for gm as a tech guy next to me ordered all the sam size camshaft bearings, and if you read the service manual they have differnet diameters to help keep the camashaft as straight as possible in the bore due the machining process like everyone else is saying i would try new pump and o ring before i would start changing bearing and remove the engine also drain the oil and inspect for debris and cut the filter open and inspect filter element