If you do replace the cam, you would already have the oil pump out, so no way would you want to put the old pump back in. Also LS engines are notorious for wearing out cam bearings so you would want to replace those too. IMHO.
Lifter Tick - GM 4.8L Silverado
- Thread starter JN94
- Start date
When you say “ slow to come up”, my 6.0 with 290,000 miles takes 3-4 seconds to reach full pressure.
Just to confirm, the oil flow on the passenger side is better and varies with rpm? Cylinder 5 is the 2nd from the back on the drivers side and the poor oiling theory would fit.
Mods, I used this generic schematic to show the numbering system.
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The oil galley on the drivers side can be checked by pulling the press fit plug from the back of the block. That would require dropping the transmission. If you did that you should replace the torque converter and rear main seal while you’re there.
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Same here
Correct about the flow being better on passenger side.
Owner of the truck said absolutely not on an engine swap.
THIS!
I'm going to throw this out there. There is a famous diagram out there (I'll try scare it up later) that shows the oil galleries in the block of an LS engine. There is one gallery in each side of the block. I believe the galleries in both sides of the block deliver oil to the lifters. The way the oil makes it way to the rockers, is that the lifter bore receives oil, delivers it to the inside of the lifter through a port in the side the lifter. It then delivers oil to the inside of the hollow push rod and then shows up at the top of the head at the rockers. The sealing of the bottom of the push rod is simply a metal on metal sealing between the mushroomed bottom end of the push rod against the concave upper end of the lifter. There is a check valve in the lifter to keep it from draining and allow oil to flow through the port at the top of the lifter into the hollow push rod.
The oil port for the cam bearings is drilled from the driver's side gallery. Although a set of cam bearings has two holes, only the driver's side hole in the bearing is aligned with the port in the block. When you hammer in the bearings you have to be careful to align the hole in drivers side of the block with one hole in the bearing. From there the oil just leaks off back into the pan.
Now, looking at the diagram, it looks like the gallery in the driver's side intersects the horizontal gallery. Oil moves downward through the gallery to feed the cam bearings and some continues to the top of the main bearings. Also, I believe the center of each connecting rod is drilled to take oil from the main bearing and feed it up through the center of the connecting rod to journal bearing of the rod where the pin of the piston rides.
So basically I'm thinking all the oiling for the main bearings, rod bearings and rod journal bearings is all done from the supply of oil from the drivers side horizontal gallery,.
Now imagine if the cam bearings are worn (and they are guaranteed to be worn at 289,000 miles), and there is wear in the main bearings, connecting rod bearings, and the oil will escape easily into the pan. This means there might be less pressure available to send oil to the lifters, through the push rods and to the top of the heads. This means the lifters might be starved of oil resulting in wear in the lifters and rockers. In that case a person might find wear between the push rod and lifter resulting in ticking.
Can someone confirm if the oiling for the main bearings come only from the drivers side gallery?
In any case, the fact that no oil is showing up on top the head passenger head should ring alarm bells.
My two cents. Thanks.
The oil port for the cam bearings is drilled from the driver's side gallery. Although a set of cam bearings has two holes, only the driver's side hole in the bearing is aligned with the port in the block. When you hammer in the bearings you have to be careful to align the hole in drivers side of the block with one hole in the bearing. From there the oil just leaks off back into the pan.
Now, looking at the diagram, it looks like the gallery in the driver's side intersects the horizontal gallery. Oil moves downward through the gallery to feed the cam bearings and some continues to the top of the main bearings. Also, I believe the center of each connecting rod is drilled to take oil from the main bearing and feed it up through the center of the connecting rod to journal bearing of the rod where the pin of the piston rides.
So basically I'm thinking all the oiling for the main bearings, rod bearings and rod journal bearings is all done from the supply of oil from the drivers side horizontal gallery,.
Now imagine if the cam bearings are worn (and they are guaranteed to be worn at 289,000 miles), and there is wear in the main bearings, connecting rod bearings, and the oil will escape easily into the pan. This means there might be less pressure available to send oil to the lifters, through the push rods and to the top of the heads. This means the lifters might be starved of oil resulting in wear in the lifters and rockers. In that case a person might find wear between the push rod and lifter resulting in ticking.
Can someone confirm if the oiling for the main bearings come only from the drivers side gallery?
In any case, the fact that no oil is showing up on top the head passenger head should ring alarm bells.
My two cents. Thanks.
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FWIW here is that PDF about LS lubrication sytems. The oil pressure for a LY6 is normally 40 psi at 2000 rpm, not 20 psi. The sketch of the lubrication system is handy. Enjoy.
https://engineprofessional.com/articles/EPQ123_44-52.pdf
https://engineprofessional.com/articles/EPQ123_44-52.pdf
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Interesting. Anyway it was fun looking into it. Tap, Tap, Tap.....
One update is a LS hydraulic lifter has a body, plunger, spring and metering plate ( not check valve).
They can look into it. I'm not trying to open up someone else's can of worms.
I'd say to the contrary. Especially if it was short tripped much of the time.
It wasn't short tripped , but rpms never exceeded 3.5k basically it's entire life.
Not sure that low revs would be bad for the cam. I don't think they get lubed from oil slinging off the crank (like the cylinder walls).
Has it been ticking away for 110k? If so... maybe just let it tick. It's likely damaged. Or it's something completely else.
Cracked flexplate would have given up by now, right?
Has it been ticking away for 110k? If so... maybe just let it tick. It's likely damaged. Or it's something completely else.
Cracked flexplate would have given up by now, right?
The owner told me it's been doing it for awhile. Truck still has factory everything under the hood minus coil wires and spark plugs. Also discovered a front seal leak from the transmission. Owner said they don't want it fixed if it requires removal of the trans. If revved high , it blows what appears to be carbon pieces from the exhaust.
It appears the drivers-side rockers and possibly the lifters are not getting enough lubrication. I would guess one or more pushrods will get bent and the valves on the drivers side will stop opening fully.
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