I have a 08 c6 with 100k on it, just wondering if anyone has noticed this before dealing with ls based engines and oil systems.
lets see if I can explain this well enough.
so car has what I consider good oil pressure, I'm running the newer 5w40 oil, it's got what I consider good oil pressure, at 190 oil Temps 32 psi at 750rpm idle, and it goes up there there, I've not really logged it, but I've seen 50psi. the odd ball thing, and I've replaced the oil pressure sensor with a new oem gm one, is whatever oil pressure I'm at when I step in the gas, it will hold that or lose 2psi for a second or 2 and then start climbing with rpm, or if in let off, it jumps up too. it a manual, so rpm doesn't change on and off the throttle much. for example, cruising 55mph in 5th gear 45psi oil pressure, give it say 1/4 throttle, oil pressure will dip a psi or 2 kinda hold for a second and then build with rpm but when you let off, it will jump up a few psi oil pressure. in this example I'm only on throttle say 20sec, enough to gain maybe 500 rpm or so. it's almost like the oil pressure is effected by load, but it will blip down and then climb. I need to log a full throttle gear pull to see what max pressure hits, but just seems weird to see the oil pressure dip with the throttle like that. never noticed it on any other car, and wasn't looking for it on this one till one day i just happened to notice.
the car is pretty stock, no internal work or cam, I've done a oil pan gasket because it was doing the ls seep in the corners and at a different time the balancer, because they all wobble around 80k it seems haha. I didn't touch any oil pump, or the pickup o ring which looking back, I really should have done while in there. but pan was spotless, no sludge or anything,, I've done one track day with the car 2 years ago(could have been doing it then and I just didn't notice) , sent off an oil sample to black stone for that day and all came back good.
just seems odd haha. motor sounds fine. I've seen on the trucks there's a oil port side of the block by the pump I guess with the right fittings you can put a manual gauge on. you think that's worth doing?
so just to follow up, I took it to another track day. car did really well, ran 4 sec a lap faster after cooling mods let me drive harder longer and then it popped an oil cooler line. long story but hose i ordered was not what I got and since it was only a short piece, it didn't have much markings on it, so I didn't catch it. anyways since I thought it might have already had worn bearing and definitely had no oil pressure for a bit. I sent out and oil sample, but got impatient for the results and dropped the pan to check the bearings. ended up they all looked perfect, sample came back and showed no bearing material either.
since I had it down and it was a hassle I went ahead and rolled some new ones in. while breaking it in I noticed the same oil pressure dip. so I got to thinking, there's a rash of non oem parts on Amazon being sold as new acdelco oem sensors. of course I had used one of those on this car years ago, but it's not driven as often and one recently on my yukon when I did the vlom mod. that Amazon acdelco while looking the same to me went bad in a few months, so I replaced it with a dealer oem and it's been perfect. so that got me thinking maybe I had a bad one in the c6 too. so I ordered a replacement from gm parts direct. got it installed and bam, no more oil pressure dip.
the bags look like the older dark blue acdelco ones. something I'd never question. but be careful buying off Amazon. lots junk being sold as oem.
left is the gm parts direct one, right is the Amazon acdelco one. definitely different.
the yukon one was even a better fake.
for this pic, left is the original 140k one. middle is the Amazon, right is the local dealer. only different I found was the font is wrong on the Lazer etched part number. it lasted a month or so and started to flicker after an hour long drive, then got worse. if you sort the Amazon listing by 1 start. there's a few hundred saying it's a fake and failed them quickly.
fft