2004 silverado 4.3 208k

[chorty]

Drained out the 5w-20. Idling I was making 15-20psi hot

For the summer I decided to go with some 15w40. Book calls for nothing heavier then 30 weight, but I'm working the truck quite hard moving material in blistering heat.

Any I'll effects or warnings, or ride out this 40weight for the summer?

 

[HyundaiAbuser]

Nope, you're good to go.

 

[nascarnation]

I'd say 15 psi hot idle on a 200,000 mile engine with 5W-20 means it's in great shape.

 

[We're Metals]

I'd say 15 psi hot idle on a 200,000 mile engine with 5W-20 means it's in great shape.

Almost new even

 

[addyguy]

15W-40 is a great summer oil for that engine.
I wouldn’t have used 5W-20 in it in the first place; calls for 5W-30.

 

[FTTSHO]

Drained out the 5w-20. Idling I was making 15-20psi hot

For the summer I decided to go with some 15w40. Book calls for nothing heavier then 30 weight, but I'm working the truck quite hard moving material in blistering heat.

Any I'll effects or warnings, or ride out this 40weight for the summer?

As a fellow GM 4.3 vortec owner, I’ve always contemplated on trying out 20 weight oil in my engine just for “science”.

Right now I’m running mobil 1 esp 0w30, and she runs super smooth.

Did the engine run good on 5w20? No abnormal noises? Did you notice any metal shavings on the drain plug magnet?

 

[chorty]

Clean magnet. I took the time to cut open an oil filter the ***** way to check the cleats. Clean. Book calls.for 5-20 if its super cold, or 5-30 for warmer climates.


The 1998 4.3 vortec has 289k on it. All that has is skirt chatter when its -20*F on the first fire up for the day.

On this 2004, I don't hear anything different, before or after the 15w-40.

Makes nearly 60psi cold, and holds 40psi at a hot idle.

I do agree, 15psi on 5w20 hot with 200k is quite tight still. Only reason I ask. It rarely gets shut off. On at 5am, and key on until 8pm.

I'm more concerned keeping everything floating on oil then fuel mileage. I'm working the living **** out of it. So MPG is irrelevant. I promise its the only 4.3 around with a nv4500.

 

[ka9mnx]

M1 FS Euro 0w-40 year round

 

[chorty]

M1 FS Euro 0w-40 year round

I considered that.

But I already have 3 barrels of this 15-40.

 

[ka9mnx]

I considered that.

But I already have 3 barrels of this 15-40.

Sorry about that but you wanted the best...

 

[chorty]

i was more worried if 15w-40 was the worse.

 

[ka9mnx]

Personally, I don't use diesel oil in a gas engine. If it's a diesel rated oil.

 

[BrendanC]

Personally, I don't use diesel oil in a gas engine. If it's a diesel rated oil.

echo this. M1 0w-40 or Valvoline EP HM 5w-30 for GM stuff. Valvoline R&P may not be a bad idea for an OCI or two.

 

[4WD]

Regardless of what folks post here about “W” and the hot end - 15W40 HTHS can be considerably higher than a 0W40 …
Many are heavy in Grp2’s as well …
(bcs they can) …

 

[chorty]

Personally, I don't use diesel oil in a gas engine. If it's a diesel rated oil.

I do remember seeing a clip from Dave's garage of some.gasser.BMW turbo that blew up a piston/bore from using diesel engine oil.

Maybe I'm next.

 

[50yr Street Mech]

I get it, you got 3 barrels of 15W40, but you more than doubled you're hot idling oil pressure. I'm no rocket scientist by no means, but, that added pressure can't be good for the front/ rear seals. Especially seals with 208k on them. Maybe you can thin it out a bit to lower the oil pressure ????? I'm not looking for you to spend a boatload of $$$$ buying a thinner oil, but, the consequences of a rear main or front main oil leak far outweighs the cost of some cheap thinner oil to mix in with the 15W40. You say you need this truck, and it runs all day long. Maybe try to thin out the oil to a idling hot PSI of 25 PSI, just for the summer anyway. A little peace of mind

 

[50yr Street Mech]

Maybe you can find some cheap 0W20, or even a cheaper 0W20 " blend". I think 0w16 is the thinnest, but I don't know what price it's running at. It's a fairly new grade of oil.

 

[chorty]

When I swapped the nv4500 I did seals. And even still, The way seals go on the shaft, the more pressure the more they seal, assuming the splash is that intense, which it shouldn't. Its not a hydraulic cylinder making 2500psi.

And what's a rear main? $15? $25? Let's assume $50.

Then again, the average DIYer does not own a full floating 10k# hoist spanning 50ftx50ft, which also swings over a 12ft walk down service pit. I dropped the old gearbox, then lifted the entire truck and set it into the other bay, as I had another headache to deal with that needed the pit.

Made the nv4500 swap a zero struggle. The most miserable part in the whole process was installing the clutch petal. Them 2 bolts under the dash sucked. I ended up taking the seat out. I wanted bucket seats anyways.

 

[thastinger]

I get it, you got 3 barrels of 15W40, but you more than doubled you're hot idling oil pressure. I'm no rocket scientist by no means, but, that added pressure can't be good for the front/ rear seals. Especially seals with 208k on them. Maybe you can thin it out a bit to lower the oil pressure ????? I'm not looking for you to spend a boatload of $$$$ buying a thinner oil, but, the consequences of a rear main or front main oil leak far outweighs the cost of some cheap thinner oil to mix in with the 15W40. You say you need this truck, and it runs all day long. Maybe try to thin out the oil to a idling hot PSI of 25 PSI, just for the summer anyway. A little peace of mind

The seals are not pressurized.

 

[chorty]

The seals are not pressurized.

Not according to the oil gauge!!!