Ok, so I did the cam swap with upgraded valvetrain (stock rockers) ls7 lifters, double roller timing chain, and ls6 ported OP. Car is a 2002 C5, so it has the existing LS6 intake with the 241 heads, M6, 36k miles on it. Started the swap last Friday, had to wait on headers until this past Thursday. So this morning, finally got the car running because of work and Hurricane Irene coming through. On first initial start-up, the car fired right up, actually idled half decent, and watched the oil pressure sit at 10lbs for 3-5 seconds and then SLOWLY pump up to 3. After its pumped at 30, it takes maybe another 3-5 seconds and slowly starts dropping. I let it get back down to 20, shut it off. Tore it back down, thinking maybe I didn't bend the pick-up tube enough for the O-ring to seat properly?

So we FINALLY get the front tore back down, looked like a hair of a gap between the pump and the flange. I used a new blue O-ring, that was exactly identical to the one removed, bought it from the dealer. My question is, I bent it a hair more, used the *now ever so slighty used o-ring*, pried up on the flange, while a buddy torqued down the bolt. I took a light to it and from the best of what I can tell, its seated properly. Is it possible to pinch the O-ring if the bolt is torqued down TOO MUCH? I got the same exact result upon start up this evening.

Also, the spacer on the right side of the pump is a 3 hole, while the left side is a 2 hole. Left side has 2 bolts for the 2 openings, straight spacer. The right side still only has 2 bolts, but 3 holes. I put the opened hole of this spacer facing the crank, because of the opening on the pump behind the casing. Is it supposed to face towards the steering knuckle (or outside)? Should I have still replaced the *now ever so slightl used O-ring* with a brand new one? It looked fine...? Just not understanding how a motor can start at 10 lbs for 5 seconds, slowly creep to 30 and begin to bleed back down within a mattr of 20-30 seconds? I'm pulling my friggin' hair out on this one....

 

Also, forgot to add, would O2s not being hooked up,even begin to equate to a maybe perhaps an electrical problem? Didn't have any extensions with the longtubes, so those aren't hooked up. Also, after the second attempt this evening, we changed the oil, lowered it back down with the wheels on it, and added an additional 2 quarts (didn't know the C5 took almost 8 quarts!?), and the problem remained the same. Just giving any and all possibilities here, I'm frustrated as hell because of how much of a PITA the stering rack is, and I don't want to have to dick with this thing but one more time! All necessary lube was put on the cam, bottom of the lifters and top and bottom tips of the pushrods.

 

Is it possible you messed up ur opsu when you took you intake manifold off?

 

The OPSU sits on the back of the block, that remained unharmed, I'm 99.999999% sure. The connector on the back of the intake was loose, but it caught the connection plug fine, just sits a little loose on the intake. I believe that sensor to measure manifold vaccum IIRC??? Still, not so sure that would relate to the OP issue, or would it?

 

I got to thinking... would a faulty seal between the cam retainer plate and block cause these screwy readings/symptoms?

 

Anybody else?

 

Yes the cam retainer plate has a gasket on it that if it goes bad when retorquing it down would cause oil psi problems. Did u put the o ring on the pickup tube or did u seat it up onto the pump? Aldo did u you some grease to help it slide up

 

I installed the o-ring onto the pick-up tube, but did not grease it.

 

I usually like to grease it to help it slide in and not pinch but as long as you did it on the pickup tube it should be ok. Looks like you'll have to pullit apart and check it again along with the retainer plate. But before you do why not check the psi with a manual gauge just to be sure

 

I'll go ahead and check all my grounds and see what it comes up with when hooking a mechanical gauge to it.

Just curious though... would not running any O2 sensors cause this kind of issue? My buddy said he's seen EGR codes and such get thrown from no running O2s, but neither of us could see why it would have any bearing on oil pressure, figured I'd ask though. Right now I've just got the LTs on, forgot about the O2 extensions when I placed my order