5.3 LS Top End Noise

[Nmbr1GMfan]

Originally Posted by Mark Ruset

Sad to day you may have a worn camshaft. Have seen a few in the dealership with a top end tick noise.

Giving that it's intermittent I would say there is a chance it's not the cam.

[FED 387]

GM had a bulletin # PIP4499B regarding lifters also u might check oil pump O ring over time (yours is old 248K and 10 years) they get hard and do not seal properly allowing air to pass thru the system and causing intermittent oil pressure very common in 5.3 engines

[ss3011]

If you Google GM lifter/valvetrain noise there are a lot of "fixes" . Most involve pouring some type of product into the oil to clean crud out of the lifters . Seafoam comes to mind , or Marvel Mystery Oil . Worth a try before getting inside the engine .

[brian schuetta]

After not hearing it all weekend it came back briefly this morning when was still cold. No noise when I stopped for gas. BTW turned 249K this morning. So first thing this morning I will figure out which rocker/lifter/valve is making the noise, if it does it again, and then try some of the "fixes"mentioned. Still going to buy valve cover gaskets in case we have to pull a cover.

[stang321]

I have seen many worn push rods and rocker arms the end of the push rod will look ovaled and shinier than the rest many cams and cam bearing but not for intermittent noise I work in a gm dealership

[Greg Reimer 7376]

Seems to me with a quarter million miles on it, the expeditious thing to do would be to replace the cam,lifters,pushrods and rocker arms. If one or two parts are worn beyond the valve train's ability to compensate for itself, the rest can't be too far behind. I'm sure that engine would have a steel roller camshaft as well. It probably wouldn't go flat and put shrapnel throughout everything, it probably would just wear down smoothly,but that and a new timing chain and gear set would probably set you right up.Who do you suppose has the record for the most miles on an original engine?

[countrypuppy4865]

If this is an 07 model new body style, it could very well be a lifter problem. If it is an 07 it should have active fuel management which disables 4 cylinders to supposedly decrease fuel consumption. These lifters are prone to failing and causing problems. Eventually, it will result in camshaft wear. If it is not a new body style 07, then it would more than likely be a lifter issue. If the noise is mainly when it's cold, it is very likely that a lifter is just getting weak and it bleeds down when sitting.

[Irace007]

Check all the ex manifold bolts #7/8 are usually the culprit.We've done some of the HV oil pumps and they do work.Have seen a ton of bad lifters/rockers.(Noise is most noticeable on cold starts.)
former GM tech...good luck

Marty

[john kunsak]

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 ***!

[john kunsak]

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 ***!