Re: 5.3 LS Top End Noise
 

we have used several of the kral brackets to repair the broken exh manifold bolts& they save hours of time. ive had a 2010 suburban with afm with 30,000 miles& the lifters seemed noisier than the older ls engines , but the same time afm started gm went to the electric fan to replace the engine driven fan& the electric fan cycles on &off. so the lifters may seem louder without the fan running to mask the sound. i have a 2013 cop tahoe now with 130,000 & the lifters are noisier but the performance doesnt suffer any. as far as the oil pump to pickup o ring--when we had that problem it came with low oil pressure when engine temp is cold &normal pressure at warm temp. the old design o ring is black& the gm upgrade is red.after 50 years of 409s &big blocks ive come to really like the ls7 in my copo except for 1 thing--pulling cyl head to remove lifters is a pain in the ***!

Re: 5.3 LS Top End Noise
 

we have used several of the kral brackets to repair the broken exh manifold bolts& they save hours of time. ive had a 2010 suburban with afm with 30,000 miles& the lifters seemed noisier than the older ls engines , but the same time afm started gm went to the electric fan to replace the engine driven fan& the electric fan cycles on &off& seems quieter when running,. so the lifters may seem louder without the fan running to mask the sound. i have a 2013 cop tahoe now with 130,000 & the lifters are noisier but the performance doesnt suffer any. as far as the oil pump to pickup o ring--when we had that problem it came with low oil pressure when engine temp is cold &normal pressure at warm temp. the old design o ring is black& the gm upgrade is red.after 50 years of 409s &big blocks ive come to really like the ls7 in my copo except for 1 thing--pulling cyl head to remove lifters is a pain in the ***!

Re: 5.3 LS Top End Noise
 

Haven't heard the noise since I started this thread. Now a different but similar subject, what viscosity oil should I be using in an engine with this many miles? When new it used 5W30, at 150K switched to 10W30. Should I go to a heavier oil? Using Castrol Hi Mileage type.