raven154

iTrader: (14)

My LS6 has stock crank that has been polished and chamfered, Compstar rods, LS7 lifters, and an LG cam. I bought this engine off here from a guy in Florida. He told me the engine had been blueprinted and I was going to have some clearances check but ran out of money pretty much. It was a fresh build with new rods and forged pistons along with a used LG cam. I don't recall if it had new cam bearings.

When I first installed the engine I ran 5-30 and had 28lbs at hot idle. Well my sending unit started acting up and so I unplugged it until I could get it fixed. I kept an eye on level and made sure I didn't hear any sounds. Once I replaced several thousand miles later, my oil pressure indicated by the car was 7lbs hot idle. I replaced that sendin unit and the connector and only gained about 1lb. Since it was so low, I started running Castrol GTX 20-50 and now my hot idle is 17-18lbs.

The car has never made a sound even when the oil pressure was down at 7lbs. I did a proper engine break in and since then have run the car pretty hard. The engine has about 10k miles on it and has ha low oil press ever since break in but was always performed flawlessly. What would be the most likely cause of the low pressure? I'm wanting to sell the car soon and don't want to sellnit to someone knowing I have an issue with the engine.

Sorry for any spelling errors. I'm posting from my phone.

Any help would be appreciated.

Sales4@Texas-Speed

iTrader: (4)

When the engine is cold does it have good oil pressure? If so, its possible that your oil pump pick up tube o-ring is damaged. The slightest nick or pinch in those rings can cause oil pressure issues. I would also check the oil for any metal flakes or shavings, that would be an obvious sign of an issue.

raven154

iTrader: (14)

With 20-50 it's about 45-50lbs when cold and I have never seen any metal in the oil that would indicate a high wear situation. I'm about to pull the trans. I guess I can replace the oil pump and pick up o-ring just for good measure. I am running a double roller with oil pump shims. I suppose the oil could also get pushed out around shim. I'll pull the front cover and check it when I pull the trans.

I had though about installing a high volume high pressure melling but don't know if that is wise or not.

Whiteaw57

iTrader: (2)

the shims aren't a problem. I would think it is definitely a nicked o ring. my ls1 cold makes around 60 cold and 38 hot at idle

MM98

iTrader: (13)

How about at cruise & wot, what's the psi at? If you already have a new pump on hand, then I don't think installing it is un-wise. I agree with John & Whiteaw57, possible worn/damaged o-ring causing your problem.. Possibly even a dying pump, which is not uncommon for these motors.

Whiteaw57

iTrader: (2)

definitely has a weak system. In my experience the oring either worked or it didn't but I know its possible to have a pinhole in it that would cause the problem. at this point it depends on how much time or money you have. If you have a pump change the pump and oring. if you haven't bought a pump yet id change it to the green puffy oring, just be sure to put oil on it and not pinch it, then see what happens. best of luck either way

Sales4@Texas-Speed

iTrader: (4)

I would bet money on it being the o-ring. 9 out 10 times someone decribes this problem to me it ends up being the o-ring. They are a real pain to deal with, if you don't install them right or they have the slightest damage they will do things exactly like what you are describing.

Whiteaw57

iTrader: (2)

what sucks the worst about them in my opinion is having to drop the oil pan down. My buddies gasket didn't reseal over the oil filter.

Sales4@Texas-Speed

iTrader: (4)

Yeah they are pretty annoying. I have seen "certified" gm techs screw this install up before multiple times.

raven154

iTrader: (14)

Well that makes me feel a little better. I hope its on o-ring and not a bearing problem. I used lots of oil and installed it out of the car with no pan on it. I have a spare blue o-ring but you guys think I should get a green one? Would putting a small dab of RTV around the o-ring to help it seal be a bad idea? I know you dont want it going into the pump or passages. RTV can be a bad thing in an oil system.

jim ravencraft

Hi,
i would go with the post from texas speed. You may want to hook-up an external gauge to double check. Don't neglect the problem as it can make for serious issues later. Good luck and merry christmas............................
Jim

raven154

iTrader: (14)

Ok I am finally getting around to checking this. The car has been sitting for a few weeks. Where is the best place to tap into to pull oil pressure? Any special little adapters I need to pick up? I saw the kent moore J 42907 that basically replaces the oil filter but its a little pricey. I think I can hook one up a lot cheaper.

raven154

iTrader: (14)

Bump...

01ssreda4

iTrader: (96)

You pull the small plate above the oil filter off, and drill and tap it. It has a little spot thats just made for this

raven154

iTrader: (14)

I was hoping to find a plug somewhere but I guess I'm not so lucky? Thanks for the info. I googled some pics and saw that so I guess thats what I'll be doing.

Thanks

projectcam

iTrader: (12)

Don't use RTV on the o-ring! Totally not neccesary.

RyanJM

There is a company that sells gauges and they also sell a small sandwich plate that you mount between the motor and filter that has fittings for oil pressure and temp gauges. U will look to see if I have the web name otherwise u can try Google. It's like$25 or so but it is a easy way to add a gauge.

RyanJM

The site is glowshiftdirect.com and you just have to enter you car for the oil filter sandwitch adapter plate. Also when I did my MS3 cam I installed the double roller and used a SLP high flow pump, it's nice because unlike the melling we installed on my friends LS1 it's setup for a double roller so no shims are needed.

raven154

iTrader: (14)

That would be nice not to use the shims. I was just going to pull the small cover off and cut one out of 1/4" aluminum and drill and tap it. That was if I screw something up, it wont be the good one lol Thanks for the info.

raven154

iTrader: (14)

Well I decided to make my own plate so I didn't mess up the factory one just in case. If anybody is wondering, it was pretty easy. Got the aluminum plate from work and about $26 bucks at autozone and I have a back up oil pressure indicator that is mounted under the hood. I'll get it all in the car in the morning.