LQ4 No Oil Pressure
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LQ4 No Oil Pressure Ok so i finally got my 6.0 in, everything is stock except for putting 241 heads 233/239 TSP cam and my ls1 intake.
First start up i didnt have any oil pressure so i shut it off.
Changed the OPSU thinking i broke it, still no pressure.
Figured that the LQ oil pump was bad so i pulled it off and replaced it with a mellings standard pump, made sure the o-ring wasnt crushed or damaged and was installed correctly. I packed the oil pump with assymbly lube to prime it.
Started it up and STILL no oil pressure. I hooked up a mechanical gauge and oil didnt even flow into the tube.. Pulled the oil filter and started the car and oil didnt even come out..
the barbell galley plug in the back of the block is there.
Any sudgestions? only other thing we can think of is maybe my oil pickup tube is busted somewhere.
First start up i didnt have any oil pressure so i shut it off.
Changed the OPSU thinking i broke it, still no pressure.
Figured that the LQ oil pump was bad so i pulled it off and replaced it with a mellings standard pump, made sure the o-ring wasnt crushed or damaged and was installed correctly. I packed the oil pump with assymbly lube to prime it.
Started it up and STILL no oil pressure. I hooked up a mechanical gauge and oil didnt even flow into the tube.. Pulled the oil filter and started the car and oil didnt even come out..
the barbell galley plug in the back of the block is there.
Any sudgestions? only other thing we can think of is maybe my oil pickup tube is busted somewhere.
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Did you properly shim the oilpump gears and outer body upon installation? I'd double check the pickup. Oring is properly seated
Double check the depth of the pickup VS. oilcan. I hope you PRELUBED the engine prior to starting it. Good luck.
Double check the depth of the pickup VS. oilcan. I hope you PRELUBED the engine prior to starting it. Good luck.
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I haven't let it run long honestly 4seonnds is the Max it has ever ran. O-ring is probably seated
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From: Lloydminster Alberta Canada
I am currently having similar grief with an L92 engine that has been completely disassembled and reassembled with katech rod bolts LS3 cam lifters cnc LS3 heads new non afm oil pump vvt deleated. I have it on an engine break in stand. when I installed the pump I did fill it with assembly lube and was careful installing the pickup and o-ring. I have yet to fire the engine but just cranking over with the starter there is O oil pressure and yes I have the spark plugs out and no fuel. I removed the mechanical gauge and there was still nothing coming out of the gallery at cranking speed. I removed the oil filter and there was no oil coming out there either. I removed oil pan and double checked the pickup. I have now reinstalled the pan and am going to use a pre oiler to put pressure to the engine and make sure the pump is primed. I have heard of the o-ring leaking on the pickup tube not allowing the pump to prime as well as if a cam bearing is installed wrong or spins it will shut off oil to the top end of the engine but should still have pressure at the oil filter? I have read all there is to read online on this issue and I am tempted to just fire the engine up as some have stated and the oil pump will prime itself eventually? I have built many sbc and bbc engines in my life but this is the first assembly of an LS engine. This thread made me join LS1 tech I have read allot of the posts here and enjoy all the different opinions. I cant wait to figure out my oil issue and hear this guy run with open exhaust on the test stand!!!
Last edited by strmachinist; Feb 1, 2014 at 04:35 PM.
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I am currently having similar grief with an L92 engine that has been completely disassembled and reassembled with katech rod bolts LS3 cam lifters cnc LS3 heads new non afm oil pump vvt deleated. I have it on an engine break in stand. when I installed the pump I did fill it with assembly lube and was careful installing the pickup and o-ring. I have yet to fire the engine but just cranking over with the starter there is O oil pressure and yes I have the spark plugs out and no fuel. I removed the mechanical gauge and there was still nothing coming out of the gallery at cranking speed. I removed the oil filter and there was no oil coming out there either. I removed oil pan and double checked the pickup. I have now reinstalled the pan and am going to use a pre oiler to put pressure to the engine and make sure the pump is primed. I have heard of the o-ring leaking on the pickup tube not allowing the pump to prime as well as if a cam bearing is installed wrong or spins it will shut off oil to the top end of the engine but should still have pressure at the oil filter? I have read all there is to read online on this issue and I am tempted to just fire the engine up as some have stated and the oil pump will prime itself eventually? I have built many sbc and bbc engines in my life but this is the first assembly of an LS engine. This thread made me join LS1 tech I have read allot of the posts here and enjoy all the different opinions. I cant wait to figure out my oil issue and here this guy run with open exhaust on the test stand!!!
Reason why i posted this is because i have searched.. why doesnt the oil pump come with instuctuion about shimming, the only thing i have ever heard people shim is the relief spring. i dont want to tamper with the pump and void my warrenty.. my stock pump wasnt shimmed so this one should be shimmed since its the exact same model number. since you seem so knowledgeable about shimming, could you share your wealth of knowledge?
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You NEED to take the pump apart after it is mounted loosely and shim the gear with 3 feeler gauges. spaced evenly apart. You really need to see a pic of how it's done. I don't recall exactly the procedure, but I know for a fact that you CAN NOT simply toss the pump on and torque it like SBC /BBCs.
Again. try a SEARCH
Again. try a SEARCH
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From: Lloydminster Alberta Canada
I believe you are correct about the oil pressure routing. It has to be pump pickup/o-ring or something blocking/porosity in the gallery? I have spoke to experienced techs at GM about this issue and read there diagnosis to low or non exsistant oil pressure. Everything points to the above stated? I have never seen anything about "shimming" the pump I know it needs to be centered on the crank snout I believe with a .002" feeler gauge after snugging up the pump but like I mentioned I am relatively new to these engines. I am going to figure this out!!! Lol today is only day two for me with this issue. I never did see my engine running prior to tear down.
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I can not find the one thread/pic I was referring to. I know I saved it somewhere. It must be on my desktop at home. You can use this too.
https://ls1tech.com/forums/generatio...questions.html
https://ls1tech.com/forums/generatio...questions.html
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From: Lloydminster Alberta Canada
Well guys I put the pre-oiler to her after work today and she holds oil pressure momentarily but wont make oil pressure on the starter. Wouldnt that eliminate a missing plug? I am a novice engine builder not a pro by any means but shouldnt the pump make pressure at starter cranking speed? I thought prelubing it would give the oil pump the prime it needs? But then I dont think it would fill the 2 foot pick up tube would it? I am at a loss here. The stand wont let me compleatly remove the pan so I am going to lift it and start digging into it I guess. Uhg 
I hope your having better luck than I am Lol. I am going to double check O ring/pick up,gallery plugs oil pump etc? thanks guys!
I hope your having better luck than I am Lol. I am going to double check O ring/pick up,gallery plugs oil pump etc? thanks guys! Last edited by strmachinist; Feb 1, 2014 at 07:13 PM.
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mine was pulled from another vehical to go in a 69' camaro i bought it off the guy because his wife wanted a different setup. i bought the block complete intake to pan cover to cover, the only thing i put onto the block was heads cam oil pan new covers and a new oil pump, i will have to go look to see if the front one is installed, i will come back with pictures.
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also i must clearify i didnt even have oil pressure with the oil pump that came from the factory.
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I hooked the pre oiler back up to it tonight and upped the pressure to 75 lbs at the tank. I hooked in at the front of the block on the drivers side. When you remove the plug you can actually see the plug in the gallery running along the side of the block. I cracked the valve and put 25 lbs to the engine as I cranked it in increments of 5 seconds or so. I finally started to see the gauge fluctuating with the starter so I shut the valve off from the preoiler and watched as it made oil pressure on its own. After the engine has sat any length of time it wont prime itself. I am sure there has to be hole in the pick up tube or a leak at the O ring on my engine. And the slightest little leak is not letting the pump fill the lengthly pick up tube. 40 lbs engine oil at starter cranking speed.
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From: Lloydminster Alberta Canada
It took allot of cranking to get oil pressure Mista Blazer!!! And like I mentioned 40 lbs at starter cranking speed. I could stop and let the gauge go to O then crank it over and it would jump instanly to 40 lbs. But let it sit a few minutes and all the lube runs out of that pick up tube and it wont make oil pressure again. I am getting a new O ring and going to pressure test the pick up tube for leaks. I dont know? Maybe a small amount of gasket maker on the pick up tube flange mating surface wouldn't hurt? I hope you get your 6.0L figured out soon!
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Not yet, I am still using the F-body tube and pan. How much are those oil guns? The motor hadnt been started in over a year, its been an engine stand motor.
When we go to check the oil pickup we are going to replace the bearings as well :/ so if anyone knows a cheap place to get those tri-coated main and rod bearings or offers a military discount it would be greatly appreciated
When we go to check the oil pickup we are going to replace the bearings as well :/ so if anyone knows a cheap place to get those tri-coated main and rod bearings or offers a military discount it would be greatly appreciated
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From: Lloydminster Alberta Canada
A pre oiler would be quite easy to make but I am sure you should be able to rent one from an engine shop or sometimes auto stores have them for customers that buy a rebuilt engine. I figured my problem out tonight 4 sure and it was the O ring. I bought one at the local dealer today 12584922 red/orange. When I removed the pickup tube and looked it was blue slightly larger in diameter and a lil thinner. I did a little more research and I read somewhere there are 4 diffrent O ring sizes? This could be totally irrelevent to your problem just thought I would mention. As well as recommend you check that engine with a prelube tank. When you tear into the bottom end of one of these angines fasteners need replacing and there are a few other items a person has to be careful. If you replace rod bolts use Katechs or GM only! Stay away from other names as you WILL need to resize rods. Some guys will reuse the stock fasteners but they are all tourque to yeild fasteners and are not recommended to re use. If you have oil pressure with a preoiler you can narrow down your problem. Theses motors have an incredable bottem end If there is nothing wrong down there I wouldnt wast your time? Just my opinion I have torn a few down and it was piston problems in all but one. This engine by the way now primed itself within 3 5 second starter intravels and came up to 38 pounds.I am lucky enough to have put royal purple break in lube on all bearings on assembly so I can breath easy doing this . I hope you are able to find a preoiler get some pressure to it and see it hold pressure on its own and rule out bearings.
Last edited by strmachinist; Feb 4, 2014 at 09:50 PM.