Oil recommendations for GM Vortec 8100

Messages
18,541
Location
Michigan
Originally Posted by Dudemanmaximus
I am in Michigan so it does get fairly cold now and then - except for this upcoming week it has been quite warm so far. I mostly run 5w40 year run in my deisel equipment and honestly could probably use it year round for every 4 cycle engine I have, but probably like lots of folks on this site I am always on the look out for a good deal on a good oil and with the fantastic Mobil rebates last year I have more than a few gallons of Delvac 1300 15w40 (was $5 per gallon) and also maxed out on Delvac 5w40. I put enough miles/hours on my trucks and diesel equipment that typically change oil 2x a year and if I have found a good deal on some 15w40 that gets used in the warm months and 5w40 in the cold. Still have Delvac 1300 in the ole Dodge though this year just have to remember plug her in! Rubberchicken what full synth 15w40 and 20w50 do you like? I think the only full syn 15w40 i have seen I think was Royal Purple but have seen synth blend 15w40s around.
I have friends just north of Flushing with a few 8.1s, and Delacroix is all those trucks see, with both over 250k now.....
 
oil burning problem can come from a problem a lot of 2001-2003 earlier 496 engines had that involved a bad intake gasket seal between the manifold and the head at the intake ports on the bottom edge of the ports where the intake vacuum leak would suck oil and oil vapor into the intake port deliver it into the cylinder where the engine would burn the oil and compression would not show low or be affected. The fix for this is to remove the intake manifold, use the new GM (only)replacement intake manifold gaskets and the new GM longer intake hold down bolts (black), original ones were to short and silver in color under the Merc black paint, that properly clamp the manifold down and seal the intake port bottom at the gasket.  This stopped the oil being sucked into the intake track and stopped the oil burning issue.  All the 496's -8.1L engines were built the same on the same line at Tonawanda, NY and then shipped to all marine engine companies like Merc, Volvo, Crusader, etc. for marinization. GM truck division actually had a recall out on these 2001 -2003 engines in trucks to replace the intake gaskets and bolts as the problem was more noticable in trucks than in the boat engines but we have seen this problem in quite a few 496's and when fixed, this fix stopped the oil burn if it was there. My 2006 496HO 8.1 likes Mobil Delvac 1300s or Fuchs SemiSyn 15w40. Burns no oil.

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Messages
1,471
Location
Indiana
In the Allison lab (we were doing durability on the 1000 series transmission) we used Mobil 1 15W50 in our 8.1s. Never had any oil related problems, all our failures were valve springs and connecting rods.
 
Messages
1,188
Location
WA
Originally Posted by madeej11
[quote=Brigadier]My dad has a 2002 Silverado 2500HD with that engine. He hauls a huge bed camper with his to AZ and back yearly. It has always consumed about 1qt/1k miles on 10W30, except when he used to run AMSOIL in it. Then he would burn 1qt every 6k OCI. [/quote I assume the Amsoil was also 10w30. Why such a huge difference on the consumption? You're saying he stopped running the Amsoil, if so was it the cost differential? The way I see it wouldn't he have been better off staying with that oil? With whatever else he was using he would have had to use another 5 qts. over that 6k anyway. Hope I'm not missing something here and asking a stupid question. Also what is the sump capacity, I imagine it's a lot.
AMSOIL used to be available locally. Now he has to order it by mail. He is not into that sort of thing. I gave him some dual rated SM T6 5W40 to try, but he refused to try it. shrug The last oil that he ran a full OCI on was Edge 10W40, and it burnt oil at twice the rate of normal. His current fill is QSUD 5W30. The sump is only 6.5 qts with filter change - not all that much.
 

wtd

Messages
2,693
Location
southwest Mo.
I would not use anything Mobil 1 as everything GM that I've used Mobil 1 in has burned more oil. While not an 8.1, I do have a 98 with the 7.4 and it uses oil with anything 30 weight. I recently switched it over to Castrol 10W-40 HM and oil consumption has went down quite a bit. This truck only has 116,000 miles on it.
 
Messages
952
Location
montreal ,canada
Originally Posted by Brigadier
Originally Posted by madeej11
[quote=Brigadier]My dad has a 2002 Silverado 2500HD with that engine. He hauls a huge bed camper with his to AZ and back yearly. It has always consumed about 1qt/1k miles on 10W30, except when he used to run AMSOIL in it. Then he would burn 1qt every 6k OCI. [/quote I assume the Amsoil was also 10w30. Why such a huge difference on the consumption? You're saying he stopped running the Amsoil, if so was it the cost differential? The way I see it wouldn't he have been better off staying with that oil? With whatever else he was using he would have had to use another 5 qts. over that 6k anyway. Hope I'm not missing something here and asking a stupid question. Also what is the sump capacity, I imagine it's a lot.
AMSOIL used to be available locally. Now he has to order it by mail. He is not into that sort of thing. I gave him some dual rated SM T6 5W40 to try, but he refused to try it. shrug The last oil that he ran a full OCI on was Edge 10W40, and it burnt oil at twice the rate of normal. His current fill is QSUD 5W30. The sump is only 6.5 qts with filter change - not all that much.
Pretty fussy guy. Let's see, the dino he was using originally burned like crazy, the proven Amsoil that worked great he doesn't feel like getting it delivered to his door and the T6 he refused I imagine because it's a 5w40. There's a couple others that were also mentioned. Sounds like a certain woman I know...Oh well.
 
Messages
1,188
Location
WA
Originally Posted by madeej11
Originally Posted by Brigadier
Originally Posted by madeej11
[quote=Brigadier]My dad has a 2002 Silverado 2500HD with that engine. He hauls a huge bed camper with his to AZ and back yearly. It has always consumed about 1qt/1k miles on 10W30, except when he used to run AMSOIL in it. Then he would burn 1qt every 6k OCI. [/quote I assume the Amsoil was also 10w30. Why such a huge difference on the consumption? You're saying he stopped running the Amsoil, if so was it the cost differential? The way I see it wouldn't he have been better off staying with that oil? With whatever else he was using he would have had to use another 5 qts. over that 6k anyway. Hope I'm not missing something here and asking a stupid question. Also what is the sump capacity, I imagine it's a lot.
AMSOIL used to be available locally. Now he has to order it by mail. He is not into that sort of thing. I gave him some dual rated SM T6 5W40 to try, but he refused to try it. shrug The last oil that he ran a full OCI on was Edge 10W40, and it burnt oil at twice the rate of normal. His current fill is QSUD 5W30. The sump is only 6.5 qts with filter change - not all that much.
Pretty fussy guy. Let's see, the dino he was using originally burned like crazy, the proven Amsoil that worked great he doesn't feel like getting it delivered to his door and the T6 he refused I imagine because it's a 5w40. There's a couple others that were also mentioned. Sounds like a certain woman I know...Oh well.
He never ran dino oil. I don't know where you came up with that idea.
 
Messages
6,773
Location
Fort Lauderdale, FL
Originally Posted by nascarnation
In the Allison lab (we were doing durability on the 1000 series transmission) we used Mobil 1 15W50 in our 8.1s. Never had any oil related problems, all our failures were valve springs and connecting rods.
GM has used quite a bit of "adequate" valve springs. Not an unheard of failure. These engines were born for 40 and 50 weight oils. Volvo Panta learned the hard way what happens when you try to push a big block on 30 weight oil. Ended badly, and never heard a 30 weight oil recommendation ever again.
 
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