L98 high-mileage oil

[Redline457]

Mine was the little black o ring on the oil pump causing low pressure at 310,000 kms. I run Castrol 10w 60 atm.

I’ve been running Castrol 10W60 as well since my engine build, engine builder recommends it on all their builds.

 

[WreckWren]

Thicker oils (especially in the cold weight) are inadvisable for stock LS motors. Built motors are a different story, you should run whatever is appropriate for your bearing clearance.
Some people want massive pressure to overcome big bearing clearances for drag motors. That's fine. Not ideal for street or stock motors though.
Excessive oil pressure produces excess heat in the main bearings which can result in catastrophic failure for stock clearances.

 

[losh1971]

Thicker oils (especially in the cold weight) are inadvisable for stock LS motors. Built motors are a different story, you should run whatever is appropriate for your bearing clearance.
Some people want massive pressure to overcome big bearing clearances for drag motors. That's fine. Not ideal for street or stock motors though.
Excessive oil pressure produces excess heat in the main bearings which can result in catastrophic failure for stock clearances.

This is also depending on the km's an engine has on it. 200k+ probably no longer have stock clearances.

 

[WreckWren]

This is also depending on the km's an engine has on it. 200k+ probably no longer have stock clearances.

Yes, hence this thread about going from 5w30 to 5w40 after 300,000.
Honestly on LS, 200,000 doesn't generally warrant a change in weight when stock. There are lots of 300,000+ motors running 5w30 too.
Even at 300,000, my oil pressure was well above minimum. I'm just playing it extra safe.
It's also worth mentioning that GM lifters hate thick oil. A good aftermarket like Johnson for example is a different story, though.

 

[losh1971]

I'm on 220k and have run 10w 40 for two years. Fixed oil use issues. I've got LS7 lifters, not sure that changes anything though. Garage who have worked on 100s of these had no problem putting in 10w 40 when they replaced the seal plate and sump gasket.

 

[WreckWren]

I'm on 220k and have run 10w 40 for two years. Fixed oil use issues. I've got LS7 lifters, not sure that changes anything though.

I'm also running LS7 lifters. It depends on the climate, but on very cold starts, the GM lifters tend not to like anything thicker than a 5w and have trouble pumping up.
If you're in an extremely hot area (Darwin for instance), it's probably fine. If not, I'd probably have a look at that oil pressure and temperature.
If your main bearings are replaced with an aftermarket set that have greater than stock clearances, or yours are especially worn, it's probably an OK weight.

 

[losh1971]

Don't want to argue with you but it's literally three seconds longer for the lifters to fully pump up if using 10w. I went to 10w for oil use between changes. If 5w is working for you then good, but it wasn't for me. You did ask for recommendations though and now you're arguing the point. Sounds like you already knew the answer you wanted.

 

[WreckWren]

Don't want to argue with you but it's literally three seconds longer for the lifters to fully pump up if using 10w. I went to 10w for oil use between changes. If 5w I working for you then good.

I'm not trying to start an argument either, just curious: why would you want to run your lifters totally bled for a few extra seconds on start up?
Aside from that, do you know what your oil pressure and temps are like?

 

[losh1971]

I changed to 10w to help with oil burning. It was using close to a litre between 10k oil changes. If it wasn't using oil I would have stuck with 5w. The trade off is 2-3 seconds of very minor lifter noise. The lifter noise is not an issue on these engines. So I chose the lesser of two. The oil consumption annoyed me. Yet it wasn't being sacked through the intake. If the engine was low km, I would have again stuck with 5w.

 

[WreckWren]

I changed to 10w to help with oil burning. It was using close to a litre between 10k oil changes. If it wasn't using oil I would have stuck with 5w. The trade off is 2-3 seconds of very minor lifter noise. The lifter noise is not an issue on these engines. So I chose the lesser of two. The oil consumption annoyed me. Yet it wasn't being sacked through the intake. If the engine was low km, I would have again stuck with 5w.

Yeah that's a good reason to go up a weight.
Lifter noise is definitely cause for concern though, all the OEM lifters even the LS7s are basically made of cheese.
Was it coming through the valve seals?