20w-50 oil

3500madmax4x4

3500madmax4x4

New member
Dec 18, 2009
119
0
0
texas
i drive LMM i have hated my oil pressure from 1st day its low like 20 to25 that kills me .. i run 15-50 from tractor supply.that help to keep it up longer.. im gonna add a large oil cooler .,the weather has alot to do with what oil i run per oil change.. plus i change my oil every month just because im bored.. once i blocked pcv and egr it help 50% in oil pressure..
 
K

keith2500hd

MOTORKILLER
Jul 20, 2008
57
0
0
Burlington,iowa
the block was not changed until LBZ. the LLY is refered to as the overheater, due to changes in intake system, cooling stack and fan control setup. the oil is cooled by coolant, so if it is not cooling sufficient the other coolant will get hot also(engine oil) thicker viscosity oil will fill running clearences(bearings, piston-cyl wall) and slowdown flow so that heat transfer can better happen. someone tested gauge panels 2003+ since ecm sends data to cluster, i remember oil psi was close but temp was on curve, 240 read like 210 on cluster. think killerbee checked this. i would recommend checking cooling system. if you find anything or oil pressure goes higher during cool season, i would change back to 40w oil. when i started working on engines, old man told me start out with lowest weight that will give good psi, as engine wears(oil psi drops) go to next weight, once you get to 50w put $ away for rebuild. he also explained that if engine is built to factory spec. a heavy weight will errode the lubricated surfaces. gas engines 20 or 30w with lowest cold winter number, diesels when i first started we used to run 30weight, but as they got better and more efficient we went to 15w40 as base oil. race engine builders recommend 50weight, but they build engines loose to gain hp by moving frictional hp to output hp. know this is old thread but was surprised nobody thought of whole system check.
 
duratothemax

duratothemax

<--- slippery roads
Aug 28, 2006
7,139
10
0
Wyoming
FWIW I just threw a stock LLY engine back in my truck for right now. Stock as in like stock single turbo, stock intake manifold, etc.

This engine has GREAT oil pressure. Like almost 30psi HOT at idle, and over 60psi cruising at 80mph. My factory original engine had OK oil pressure. The first built engine had good oil pressure, but not as good as this current one. The stock LBZ I had in there for a while had friggin awful oil pressure...thats why I started this thread. Even with 20w-50 it would be like 15-16psi hot at idle and when towing heavy in the hot weather, maybe 35psi on the highway.

This confirms my opinion that LLY's are the best... :p:

That (the stock LBZ) was one of those GM test engines. When I took it apart the bearings looked worse than 300k mile duramax's ive torn down (that LBZ that broke the crank had test time at GM, and then I put 50k on it), there was a broken off dipstick in the oil pan, none of the main caps were torqued equally, rod bearings didnt look good either.

Ben
 
duratothemax

duratothemax

<--- slippery roads
Aug 28, 2006
7,139
10
0
Wyoming
keith2500hd said:
the block was not changed until LBZ. the LLY is refered to as the overheater, due to changes in intake system, cooling stack and fan control setup. the oil is cooled by coolant, so if it is not cooling sufficient the other coolant will get hot also(engine oil) thicker viscosity oil will fill running clearences(bearings, piston-cyl wall) and slowdown flow so that heat transfer can better happen. someone tested gauge panels 2003+ since ecm sends data to cluster, i remember oil psi was close but temp was on curve, 240 read like 210 on cluster. think killerbee checked this. i would recommend checking cooling system. if you find anything or oil pressure goes higher during cool season, i would change back to 40w oil. when i started working on engines, old man told me start out with lowest weight that will give good psi, as engine wears(oil psi drops) go to next weight, once you get to 50w put $ away for rebuild. he also explained that if engine is built to factory spec. a heavy weight will errode the lubricated surfaces. gas engines 20 or 30w with lowest cold winter number, diesels when i first started we used to run 30weight, but as they got better and more efficient we went to 15w40 as base oil. race engine builders recommend 50weight, but they build engines loose to gain hp by moving frictional hp to output hp. know this is old thread but was surprised nobody thought of whole system check.
Click to expand...

my cooling system is just fine.

The 01 blocks are slightly different than the 02-05 blocks.

Im aware of the fact that there is a water-to-oil cooler...thats what the big box thing is on the oil filter base.

ben
 
RENODMAX

RENODMAX

Dead Wrong
Mar 4, 2008
3,602
0
0
duratothemax said:
FWIW I just threw a stock LLY engine back in my truck for right now. Stock as in like stock single turbo, stock intake manifold, etc.

This engine has GREAT oil pressure. Like almost 30psi HOT at idle, and over 60psi cruising at 80mph. My factory original engine had OK oil pressure. The first built engine had good oil pressure, but not as good as this current one. The stock LBZ I had in there for a while had friggin awful oil pressure...thats why I started this thread. Even with 20w-50 it would be like 15-16psi hot at idle and when towing heavy in the hot weather, maybe 35psi on the highway.

This confirms my opinion that LLY's are the best... :p:

That (the stock LBZ) was one of those GM test engines. When I took it apart the bearings looked worse than 300k mile duramax's ive torn down (that LBZ that broke the crank had test time at GM, and then I put 50k on it), there was a broken off dipstick in the oil pan, none of the main caps were torqued equally, rod bearings didnt look good either.

Ben
Click to expand...

Ben you never called me back. Send me a PM and let me know if you used that motor from Schulte or if you had to go another route.
 
duratothemax

duratothemax

<--- slippery roads
Aug 28, 2006
7,139
10
0
Wyoming
sorry bud totally forgot! :eek::

The engine runs great. I just lost one (or more?) injectors on friday when I was about 3 hours from home. Knocking and literally pouring white smoke. I had just filled up with fuel about 25 miles prior... When I shut off injector #7 with efilive the smoke and knock stops, so I replaced that injector and it still knocks and smokes. Bad FICM??? No codes, so its not the injector harness.

Its not internal because when I limped it to a gas station, when I would let off the pedal and the engine/injectors would go into DFCO mode, the engine would get totally quiet and run normally...then when I would come down to idle and the injectors would start fueling again the knock and smoke would come back. These injectors are Georges tips on my original stock LLY (150k miles) injector bodies. Normally for an LLY 150k isnt much on injectors, but this is my shit luck we're talking about. Im honestly about 1 more broken part/failure away from giving up on the dmax thing.

ScratchRob13 saved my butt though with his big gooseneck trailer. :thumb:

What I find funny (GD hilarious actually) is I ran my factory-stock original engine the hardest and beat on it the most without care, and it lasted 5 times as long as my built engine, and twice as long as my LBZ short block that I ran with basically a stock tune.
 
LarryJewell

LarryJewell

Back with his honey :)
Jan 21, 2007
10,152
0
36
58
San Angelo
duratothemax said:
sorry bud totally forgot! :eek::

The engine runs great. I just lost one (or more?) injectors on friday when I was about 3 hours from home. Knocking and literally pouring white smoke. I had just filled up with fuel about 25 miles prior... When I shut off injector #7 with efilive the smoke and knock stops, so I replaced that injector and it still knocks and smokes. Bad FICM??? No codes, so its not the injector harness.

Its not internal because when I limped it to a gas station, when I would let off the pedal and the engine/injectors would go into DFCO mode, the engine would get totally quiet and run normally...then when I would come down to idle and the injectors would start fueling again the knock and smoke would come back. These injectors are Georges tips on my original stock LLY (150k miles) injector bodies. Normally for an LLY 150k isnt much on injectors, but this is my shit luck we're talking about. Im honestly about 1 more broken part/failure away from giving up on the dmax thing.

ScratchRob13 saved my butt though with his big gooseneck trailer. :thumb:

What I find funny (GD hilarious actually) is I ran my factory-stock original engine the hardest and beat on it the most without care, and it lasted 5 times as long as my built engine, and twice as long as my LBZ short block that I ran with basically a stock tune.
Click to expand...

I know what you mean, i'm still on my stock motor too, twinned, duel fuelers and stupid tunes for 135,000 miles (stupid tunes for at least 60,000 of those 135,000 miles) and 6 years now :coolspot:
 
paint94979

paint94979

Beer Nazi
Sep 18, 2006
11,714
7
38
37
LarryJewell said:
yea, and I think there are a few idiots that call them over heaters, guess a few of the LLY's didn't get this memo :D
Click to expand...

My engine is making some noise letting me know its getting tired.... but I am pretty happy with it. Also my LLY never has run hot
 
madmatt

madmatt

New member
Apr 12, 2009
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Yeah that cracks me up when people start rambling on about all the problems. digging deeper it's always someone else's truck or a problem they "heard" of. I just say "thats funny, I work on these everyday and I've yet to see that" . I love LLY's and rarely see major issues with the one's that haven't been overly abused. My LLY repair kit is an icepick, fuel filter and a spare frprv :D
 
RENODMAX

RENODMAX

Dead Wrong
Mar 4, 2008
3,602
0
0
Yeah Ben that motor wasnt really meant to be a drop in. The guy who bought it only paid 2250 for it and said he was gonna tear it down. But apparently it resides in your truck now haha. Well Im glad all is sound mechanically with the motor and thats a bummer about the injector(s) :(
Hopefully Schulte gave you a good deal on that motor anyway.
 
scratchrob13

scratchrob13

<---30+ psi (both)
Jun 18, 2008
129
0
0
Boston|Suffield,CT|Lincoln,NH
RENODMAX said:
Yeah Ben that motor wasnt really meant to be a drop in. The guy who bought it only paid 2250 for it and said he was gonna tear it down. But apparently it resides in your truck now haha. Well Im glad all is sound mechanically with the motor and thats a bummer about the injector(s) :(
Hopefully Schulte gave you a good deal on that motor anyway.
Click to expand...

lol... I guess it's time for that built motor to get put together.
 
paint94979

paint94979

Beer Nazi
Sep 18, 2006
11,714
7
38
37
TNRGreene said:
All kinds of little clunks and rattles :eek:
Click to expand...

thats what mine sounds like i also hear what sounds like loose metal moving around :eek:... it might have also lost a few mph's in the 1/4 and some hp on the dyno. Next weekend is going to be its final trip to the track i think. then over the winter i;ll finally have it built
 
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0

03DuraMax4x4

New member
Sep 4, 2010
53
0
0
Hattiesburg, MS
Subscribing... I may have a similar problem with the "knocking". I hear it only when under load. Dealer and local GMC mechanic said it was normal, but I think it's gotten loader over the last month. I'm due for my oil change so I'll see what happens next week.
 
2004LB7

2004LB7

Well-known member
Dec 15, 2010
6,419
1,776
113
Norcal
bumping this one back up,

does anyone know how this (using thicker oil, 50 weight?) will effect the piston oil squirters? will they start spraying sooner?

and, how about the oil filter pressure bypass? because of the higher pressure will it be open longer thus letting more crap circulate rather than going through the filter?
 
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