Hey guys, I have always lurked but never registered. But now I need some serious diagnosis help. Here is the deal, I have built several ls1's ls6's (heads, cams, n2o, etc.) I am having the strangest issue with oil pressure. On a brand new 6.0 iron block short block from tsp, heads, cam, ls6 ported pump, double roller, powerbond, etc. Motor has less than 500 miles. It all began with low and fluctuating oil pressure, so I changed pump and o-ring to be safe. This solved the problem for about 50-60 miles, then low and fluctuating oil pressure, checked o-ring and replaced for good measure. Worked great for 50-60 miles then same thing again. So tore into it again and checked picked up tube and o-ring and they were perfect. I have installed a mech gauge and it is right on with the elec gauge. these are tsp ported ls6 pumps. they have no wear on the pump from either the chain or pulley. Also cut oil filter open to check for bearing particulate and all is good. Of course oil level is good. No leaks, no unusual noise. has anyone encountered this issue before? any help is greatly appreciated. thanks!

 

how low is it at idle (hot)? My 408 has an oiling problem as well. i attribute it to be a loose motor. It gets down to 20 or less at a hot idle, but it goes to plenty of pressure when revving the motor. I also have a mech guage on it, and it tells the same story as the electric but the electric reads a little higher than the mech one. It has tons of miles on it too, still runs strong. In the old days of standard SBC's sub 20 at a hot idle was fine. Guys on here swear up and down they are supposed to have like 30 at idle, but I just think my motor just has loose clearances.

 

Pressure is about 20 at any anything off idle and hangs around 5-10 at idle. As I said there is no sign of bearing material and no leaks from the rear of the block to indicate a barrel plug or oil galley plug problem. I have been running 5-30 m1 with a wix filter. The strangest thing about this is that when the pump was changed the problem went away for a short period of time but then returns after about 50-60 miles. I am just getting junk pumps? hard to beleive I would get 2 in a row.

 

that is a strange problem. Seems to me like it wouldn't be the pump as I can't see you getting 2 in a row that are bad. My guess is that it is something aside from the pump. have you changed your oil filter?

m1 5-30 is thinner than conventional 30wt oil. I run m1 5w-40 for trucks, its still cl4 and has all of the good stuff in it. Its thicker, if I was running m1 5w-30 I'm sure my pressure would be lower, but there is no getting around 5 or 10 at idle. I know my LT1 would have horrible pressure at idle about 5, but it lived forever and ran great for all 130k miles of its life until I sold it. Good luck, wish I could be of more help.

 

We ran into a problem like this at our shop in san diego. We put on PRC LS6 stage 2.5 heads, new TR 224 cam, double cain, LS6 oil pump, headers, push rods, full eshaust, LS6 intake, 37 Delphi Injectors and Welbro 255 intank pump. We had the same problem and found that the chain pushed the oil pump out further and that we had to use the spacers that are in the kit. I dont know if it was the spacers or the angle of the pick up tube but something wasnt right. So we put an LS2 chain on there and put a new O ring and everything worked great. I really think that the chain was the problem because of how the spacers can let the oil through.

 

just a guess but try the front cam retainer plate. I have seen these work lose or the seal blow out and cause the problem you describe.

 

Pull the double roller off. put a ls2 chain on it and be done!

 

did you check the oil galley plug next to the oil pump on the right side. ive had the same problem and that was it, now i install the plug then i jb weld it. no problems ever since.

 

I think what you just said was the best thing so far. GM spent a lot of time and money on making the chain and they even run that SAME LS2 CHAIN ON THE LS7. I think that it will be more then fine.

 

I just had one in with the same problem,less than 500 miles on complete including"new cam bearings" Yep,rear cam bearing had walked back into rear cover,uncovering the oil galley and losing oil pressure right there.tried 2 new pumps,checked for missing plugs,finally pressurized system from rear galley by filter up with pan off and SAW the oil blowing out the bearing/rear cam area.R&R mike and install new rear bearing,all is well now,45-50 cruise,25-30 idle.

 

Before you go to crazy on this. Have you checked the pickup to pan clearance ? Do you have oil pressure flucuations while cruising or stopping and turning ?

 

ls1builderss brought the car by and low and behold, it was the front cam retainer plate.(its great to be right, LOL!!) the seal had been blown out and the bolts were loose also. we put a new seal in, loctited the bolts, changed oil and filter, and walla! 60 psi at hot idle!!

 

Glad to see what the fix was.

 

We had the exact same problem on my build with almost the exact same parts! My front seal gasket kept going. I had a underdrive pulley put on and the oil pump machined and i think that fixed things. I believe the double roller is crap and i could have saved a lot of money and time if i would have just got a ls2 chain they should quit selling that thing! My oil pressure is good, but i do have a slight oil leak