1996 vortec 5.7 oil recommendation

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I just bought a 1996 chevrolet c1500 with the 5.7 Vortec with 167,000 miles. I want to know what weight and type to use. Here in south alabama I have always ran 10w30 conventional chevron supreme in my beater Chevy 350 tbi's but i want this motor to last. My father had a 99 suburban with the 5.7 and his finally slung a rod at 307,000 miles. I want this engine to last like that one. This is not a work truck. Just my daily driver. Currently im looking at Havoline 10w30 synthetic blend but ive had a bad experience with a 350 and synthetic oil. It was a tbi 350 but i still could see multiple leaks occuring again considering its already a high mileage engine. If not the Havoline then what do you think about the dino chevron supreme? Also i want your opinion on oil filters. Something specifically with great drainback protection. Thank you
 
I don't think you can go wrong with PYB in those engines. Fur years I ran fancy oils in my 98 4.3, but I'm just not seeing the benefit.
 
Originally Posted By: 96Vortec
This is my first vortec. What commonly fails on these engines in your experience. Whats your mileage?


Intake manifold gaskets. Yours have probably already been changed out, but watch it in case they weren't, or were replaced with the gaskets that were the original bad design. 1996 was the first year for the use of Dexcool, and those gaskets combined with Dexcool were a problem. Mine went at 66k. Other than that, my engine has been bulletproof.

Cheap parts, easy to work on, and reliable to boot, other than the gasket problem. I have used synthetic oil from the start, and haven't had a leak yet. Factory recommendation is for 5W-30 anywhere, with 10W-30 acceptable for non-freezing weather conditions.
 
Originally Posted By: ArrestMeRedZ
Originally Posted By: 96Vortec
This is my first vortec. What commonly fails on these engines in your experience. Whats your mileage?


Intake manifold gaskets. Yours have probably already been changed out, but watch it in case they weren't, or were replaced with the gaskets that were the original bad design. 1996 was the first year for the use of Dexcool, and those gaskets combined with Dexcool were a problem. Mine went at 66k. Other than that, my engine has been bulletproof.

Cheap parts, easy to work on, and reliable to boot, other than the gasket problem. I have used synthetic oil from the start, and haven't had a leak yet. Factory recommendation is for 5W-30 anywhere, with 10W-30 acceptable for non-freezing weather conditions.


+1. Id do an oil change, with a quick 500 mile OCI on the same oil, just to get consistent oil in there, then pull a UOA after 1000-3000 miles on the second change.

Look for telltale signs of a LIM leak.

If you have a diagonal radiator neck, check the cap. Plastic caps are bad. Stant caps at least were good.

Id do a change of the coolant regardless. My truck has all original, clean and bright cooling system, having never seen anything besides dex cool. Dex isnt bad in an dof itself, with new gaskets at least. Mixing it with other stuff like green coolant is. Rebaseline it by changing out the radiator and then after 1000 miles doing the radiator again, that will get >50% out at least. Any signs of brown sludge and you may need to be a bit more aggressive and/or flush the block.

Why not get some fresh Dex VI in there too, if you trust that the AT has been serviced before?

plugs, wires, and distributor all ok?
 
Originally Posted By: 96Vortec
This is my first vortec. What commonly fails on these engines in your experience. Whats your mileage?


The spider injectors go bad and have to be replaced with a conventional mpfi conversion harness which is available pretty cheap on amazon. We have a 97 305 and my dad told me the plastic intake manifold exploded?! Due to this. It was running like trash before that so i want to believe him. Ours went bad at about 190k km.

You can also run a different intake from a boat 350 vortec that has a more conventional injector set up but that would be more for a hotrod instead of a DD.

Make sure you block the air intake silencer box off with the bottom of a pop can, too. I did that back in 2006 and i think it's still there.
 
We have a few in Izusu NPR HD's. They've been run on HDEO 15w40 their entire lives with only one issue. One started Rod knocking at 330k and now gets SAE60. Going almost 40k on the rod knock with SAE60.

Skip the 5w30 if you drive your truck like a truck and want longevity. Seen too many of those engines with excessive blowby north of 150k miles using that.

I'd say a high HTHS 10w-30 at a minimum, but 15w40 being the preference.
 
My family has had a ton of trucks or tahoes with either the Vortec 5.7 or 5.0. All lasted to around 300K miles before they were either wrecked or eventually sold using various flavors of 10w30. Early in their lives we used mostly Mobil 1 but usually switch to something less expensive later on such as Mobil 5000.
 
Run whatever HM grade between 5W30 and 20W50 that gets the hot oil pressure in a good range (around 15-20 at idle, 35 or higher at cruise)-but if it hasn't been done, the lower intake manifold gasket WILL FAIL and kill your bottom end. Losing the Dexcool (if its old enough to have come with it) isn't a bad idea either-but replace thos LIMK gaskets!
 
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