4.3L Vortec V6 dino oil choice

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Based on a modern 4.3L internals and the metals used inside, what dino/hm blend oil is recommended based on paper? What I am asking is should I be looking for an oil higher in sodium, calcium, boron, zinc, moly, etc.? I currently use Maxlife blend which seems to hold up well for the frequent short/cold trips I do, however I have heard that large amounts of Moly can be corrosive to some engine metals such as copper, etc. Is this true? I know that there are a couple types of moly and this is referring to one or the other. I will always do 3k ocis with K&N, Mobil1, Pureone, or Carquest premium filters due to the worries of a faulty intake manifold gasket on this engine I will always stick close to 3,000 mile oil changes. Dexcool was changed out at the 30k mile marker for Peak Global lifetime. I just want to stay ahead of the game as I will never sell this truck. By the way, the truck is a 5-speed & has a K&N Gen II intake system with Magnaflow cat-back mandrel exhaust and a custom computer tune with 93+ octane for max lbs.power & mpg performance. Before anyone hates on the K&N filter, I also have a pre-wrap filter on the cone for the last 10k miles and I recently checked the filter itself which has held its cleanliness red color.
 
Maxlife will be fine for that engine for 5000 miles. If you are worried about your intake gasket just watch your coolant level and do a UOA and ask Blackstone to look for coolant. Never a problem. You really cannot prevent an intake gasket issue other than replacing the gasket. Lots of guys blame it on the DexCool but it is really the gasket material. If you are concerned call Zerex tech support and ask them how many gasket jobs they see on that engine.

But different anti-freeze and a 3000 OCI will not "save" the intake gaskets. If they are bad they will fail anyway no matter what you do. If you are concerned about corrosion prevention. Use Prestone anti-corrosion additive in the system. It will boost the anti corrosion additives in your coolant. Cost: <$10.
 
I was not aware the 4.3 had an intake gasket problem. Isnt it o-ringed ports and a filled nylon composite intake? My problem was the throttle body came loose on mine - and the nuts are hard to get at to re-torque them.
 
Originally Posted By: ARCOgraphite
I was not aware the 4.3 had an intake gasket problem. Isnt it o-ringed ports and a filled nylon composite intake? My problem was the throttle body came loose on mine - and the nuts are hard to get at to re-torque them.


At some point in time, all GM V engines had intake gasket trouble. Some it was due to getting rid of torque stops on the factory gaskets, others were the plastic manifolds not expanding uniformly and weakening the gaskets (most common on Series II 3.8l v6). Other times it was low coolant levels that turned the Dex Cool into sludge witch plugged up everything, and according to some people it turned the Dex Cool corrosive, causing it to eat the gaskets.

I personally have had intake manifold gasket issues on the 3100,3400 v6 engines. My neighbors 1999 Blazer with the 4.3l had his go too. Except it was too late, he only noticed something was wrong when his oil pressure dropped. Ended up ruining a few bearings. IIRC he had less than 90k miles on it.

It is too bad this happened to the GM V engines, otherwise they were pretty reliable. This debacle also turned a lot of people away from GM vehicles, especially since these issues were not just related to a few model years, but almost all of the V engines and models that covered a decade.

To the OP, just watch your oil and coolant. If coolant seems to be slowly and steadily disappearing, check your oil. Any hint of oil level increasing or a whitish hue to the oil color, change the oil immediately and get the manifold gasket changed.
 
This got blown way out of proportion from what I am asking. I know all about the gaskets and dexcool and air getting into the system, etc.
What I am wondering is if you looked on paper at the engine in question and dino add-packs, what would be the best fit? Especially with a custom computer tune.
 
Aside from the internal coolant leaks, the 4.3Ls are super easy on oil (SBC oiling system I believe). Anything will work fine.

I've racked up 230,000 miles on our 98 Blazer using whatever dino is on sale, usually Chevron Supreme.
 
Originally Posted By: 05Blazer
This got blown way out of proportion from what I am asking. I know all about the gaskets and dexcool and air getting into the system, etc.
What I am wondering is if you looked on paper at the engine in question and dino add-packs, what would be the best fit? Especially with a custom computer tune.


Any SM dino oil will work fine. Just watch the coolant bottle and use the Prestone anti-corrosion additive. When the radiator cap (or coolant bottle cap if it is pressurized) hits 5 years old I would replace it. When the caps get weak they are a big cause of air getting into the system and coolant loss or evaporation.
 
That K&N will let more dirt in the engine...think about it...would you want to pour sand in the intake or crank case?
 
Well I tore my engine down recently and (4.3l vortec 125k) and I can tell you I feed it Dino Valvoline, Chevron Supreme. It rarely sees pennzoil at the dealer when I am strapped on time.

My internals were VERY clean.

I run 3-5k OCI depending on what type of service my truck sees. I abuse the bile out of my truck.

As far as filters I use mainly AcDelcos, and NAPA gold, I also on occasion use Supertech ones.


YES watch your coolant. if you see that your constantly refilling keep an eye on the Intake manifold. I just redid mine after I noticed a steady leak. You will only see it when the engines cold though. I saw coolant running down the back of the engine and dropping off the tranny.

Its a easy time consuming fix though.

And get that garbage dex cool out of the engine now! The intake gasket that I had was a really thin nylon gasket that disintigrated when I removed it around the coolant passages. The new updated GM ones and the Fel-Pro ones are excellent replacements. usually 90 bucks and comes with TB, Plenum gasket, Distributor rotor gasket, valve cover and valve cover bolt gaskets and a tube of RTV black silicone that you need to use to seal the front and back.



Happy motoring.
 
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4.3's = Very durable engines
any 5w30 or 10w30 should do fine you could even extend the drain to 5K.
I like Castrol my self. but its all up to you.

and Dexcool really isnt to bad if you FLUSH you system but it has led to alot of problems turning to sludgy grit and distroying head gaskets etc.
 
I did a intake job on my coworker's blazer 2.8L. I could not believe the OVERSIZE intake bolts given the torque spec. They should have used Torque-to-yield design and they would have NP, IMO. The bolts just backed out. I also couldnt believe what they did to the head ports - no wonder the engine turned to a wheezer ( I use to have a couple X-11 citations and a S10 with the stock big port heads and rochseter vara-jet ( 1/2 a quadra bog, dual stage). Love thet 2.8. And easy to remember the firing order too
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Moly DTC is, indeed corrosive. So are other adds used in motor oil. That means the add pack has to be "tweaked" to prevent corrosion.

MaxLife full synthetic and MaxLife blend both have 300 PPM of Moly. Not especially high but higher than Mobil, Pennzoil, Castrol, average across the counter oils. However, the add pack has been "tweaked" to protect from corrosion. Both of the MaxLife oils meet spec "1B" in corrosion test. That is great. (I will let you Google that spec and enjoy yourself)

Motorcycle oils make a big deal about all of their anti corrosion addatives. Most all of them are 1B. It is all just part of the "total package."

If I had a reason to use a conventional oil, it would most certainly be the MaxLife blend.
 
Im currantly running MLB 5w30 in my 4.3 03' Blazer. Flushed the Dexcool last March. No problems with either. Switching to 5w30 full syn for the winter months. I must say though although Im a M1 fan the Blazer will drink Max Life for the rest of her years..
 
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