LopeyZ

iTrader: (2)

So I have noticed my TA has a lot of either piston slap or lifter clatter on start-up. Now I've also heard for years that LS1s have noisy lifters and/or piston slap and I figured mine was the same issue. Since I don't drive the car very often, I don't get a lot of opportunity to listen to the noise. But yesterday I had to move it and noticed this lifter noise corresponded with oil pressure. For a few seconds, the oil pressure hung at zero like you get if you don't fill your oil filter before swapping it on an oil change. Once it has pressure, it will see around 35 psi at hot idle and 60 at cruise. Since the filter is installed vertical, it can't be bleeding off oil pressure like you find on filters installed sideways on a block. So what is the deal with this thing? Is there an issue with the oil pump? Is this a common LS1 problem? I've just never noticed a motor taking so long to build pressure after sitting for a while. The previous owner had a thing for Royal Purple so the motor oil is Royal Purple since I haven't had a reason yet to change it... only owned the car a few months and put maybe 200 miles on it.

trans_am7935

iTrader: (15)

sounds like you need a new oil pump o-ring.