omore001

iTrader: (1)

Hey folks,

Would installing the LS1 rear cover seal on the LQ4 block lead to a low oil pressure when engine is warm condition?

I have done the oil pick up tube o-ring twice. It is correctly installed and not pinched. New oil pressure sensor was installed to rule out a faulty sensor. Low oil pressure has been verified with mechanical oil gauge. New melling oil pump was installed when built. LQ4 Short block is new from a reputable builder and although possible, I highly doubt a spun bearing although I can't rule that out until I tear the engine apart. But the new LQ4 engine has not been run hard at all since it was assembled. I want to leave a full engine tear down as a final resort. Engine runs great just reads very low oil pressure when fully warm (0-5 psi). Cold oil pressure is around 45psi and climbs with increase engine speeds. Different engine oil weight has little to no effect when attempted, no fram filter has ever been used.

I have searched the forums and gone google search crazy struggling to find the info I need. If the info I need IS on the forums, I apologize for not being able to locate it on my own. I have had little time to dedicate to repairing my project as I am overloaded with work.

I thank you in advance for your assistance to a struggling LS enthusiast.

tug686spd

iTrader: (11)

https://ls1tech.com/forums/generatio...-oil-plug.html. Check out post 14 in this thread for placement of front and rear oil galley plugs and make sure they are in.

omore001

iTrader: (1)

Thanks, I'll get under and checked to see if the galley plug and barbell are actually there. From what I read, people who were missing one or both of these had little to no oil pressure even when cold. My situation I have excellent oil pressure when cold and almost no oil pressure when warm. I will verify these are installed anyway so I can scratch them off as potential culprits. Starting to wonder if a walked cam bearing could be my issue as I have read from other threads...

lemons12

iTrader: (71)

To answer your bold question, no.

You would have 0 pressure without those.

If you really do have 0-5, the damage is done.

If you are 100% the o ring is installed correctly and not pinched (you aren't pushing it in with the pump bolted up and using a little spit to lubricate) then you have a larger issue on your hand I do believe.

omore001

iTrader: (1)

I have checked for metallic debris each time I dropped the pan for the oil pick up tube oring and I have cut each oil filter after every oil change and I have not found any metallic debris or any kind of the debris in either the oil pan or the filters.
It is frustrating chasing this issue but I will attempt to verify both oil galley plugs in the front and rear cover are present and correctly installed. I guess I may as well remove the oil pump and inspect it while I have the front cover off.

I dread having to pull the motor out but it looks like that will become inevitable if the oil galley plugs are not the culprit I am chasing.

omore001

iTrader: (1)

Hopefully some more of you guys can chime in and elaborate on the findings and resolution of your own low oil pressure when warm situation. I need all the possible scenarios which have been encountered. Thank you.

gagliano7

Maybe the bearing clearances are too much. My oil pressure when cold is around 50 psi and goes down to 40 when hot. 5w-30w oil. I think either way you will be pulling the motor. Did you try 20w-50w oil to see if it helps? Could also be a bad oil pump but i think that would be a problem cold or hot.

lemons12

iTrader: (71)

What color is the oring on the pump/pickup? Should be green IIRC.

Install pickup with the oil pump NOT bolted to the block. Use some spit to lube it. Then bolt pump to block.

lemons12

iTrader: (71)

I'd use a new oring personally.

omore001

iTrader: (1)

I havent gone 20w-50 yet but I will give it a shot since it will only run me $20 and minimal labor. 15w-40 was as heavy as I have gone. I'll try that this weekend and keep an eye on the oil pressure. Wouldnt be suprised to have some wild bearing clearances on this build. I never measured before the longblock was fully assembled. Had faith in the shortblock vendor as they were highly recommended and vouched for.

omore001

iTrader: (1)

The build was done with the green oring. Pulled it out and tried the blue oring. No change with the blue oring. Lastly attempted the red oring. Red oring by far has held the most oil pressure of the 3. But still hovers around 5 psi and erraticly between 0-5-10psi once the engine reaches normal operating temperature.

lemons12

iTrader: (71)

Who built the shortblock?

omore001

iTrader: (1)

Oil pressure is very fixed and above 40psi when cold.

Once warm, oil psi steadily drops and becomes more erratic. Will not read a constant 10psi or 5 psi or 0 psi. It will just continue to jump around in the 0-10 psi range.

omore001

iTrader: (1)

Val's automotive in Illinois. They have a good rep and I read through multiple successful builds from their shortblocks. Engine is a 370ci low comp 8.8 to 1 on a single turbo back. Forged everything except crank. Clevite bearings and hellfire piston rings. Top end complements the forced induction set up. Forced induction spec cam. 317 heads, patriot gold dual valve springs. Hardened pushrods, Ls9 head gaskets. LS7 lifters, aftermarket rockers, new oil pump, dlb timing chain.

lemons12

iTrader: (71)

They have a good rep for ls specific stuff or engine builds in general?

Tolerances are not the same between a ls1 and a SBC for instances, there are many differences.

omore001

iTrader: (1)

Engine builds in general. They mostly do sbc bbc and LS.

Starting to wish i would have saved up another $3k to splurge on a zz502 longblock. But i had so many good high performance LS parts and no immediate buyers, so I settled on building the 370 LS to meet my goals.

gagliano7

I am pretty sure i have read that Thompson motorsports have more bearing clearance and recommend using 20w-50w dino oil on there motors.

Here you go http://www.thompsonmotorsports.net/w...t32o3t6s13k8f3

KCS

iTrader: (20)

What oil pump?

It's probably loose clearances. Most engine builders (the good ones at least) will increase the bearing clearance for engines getting a power adder. A stock volume pump will show low oil pressure on the gauge with loose clearances when the engine and oil get warmed up. If you have a Melling 10295 pump, you have the stock volume pump.

64post

iTrader: (5)

^^^^ You could warm it up to 5 psi, get a pressure reading at the front of the engine on the lefthand galley plug nearest the oil pump then compare that reading to what your getting at the back of the block on top, if it's a big difference that should give you an indication that you have clearance issues...cam bearing

Old Geezer

iTrader: (3)

My LQ4 had interference w/ the support brkt on the oil pick up tube. Bolt it down, and it twisted. A bit of creative clearancing, and GTG..