Oil recommendations

[Superbuick96]

I inherented a 03' Chevy Blazer 4.3L Had 76k mi when I took it heres the OCI:
15k 30K 48k oil changed with dealership dino
76k changed with Valvoline conventional
77k changed with Valvoline MaxLife blend
I want to go fully syn, but I heard sometimes theres issues with fully syn in a motor after dino has been used for the entire engine life. Not to mention oil changes were neglected in this Blazer. Ive been a Mobil guy since I started driving 15 years ago,running Mobil 1 in my Ford Ranger. But this Valvoline MaxLife, seemed to be what the doctor ordered for this situation. But Im asking for peoples opinions on what brand and blend of oil they would recommend for this 4.3L. Also would fully syn create problems? I must say the Blazer runs strong w/o leaks, smoking, or any other problem

 

[ChiTDI]

You had a 28k OCI?
Whatever you use will no doubt clean up a lot rather quickly so run a couple short changes and keep an eye on it.
I'd go with an High Mileage oil - Valvoline, Pennzoil or Castrol.

 

[Superbuick96]

Yeah a 28K OCI on dino. The previous owners fault. I Changed it at 76K, then after 900 miles, with Max Life blend.

 

[ZR2grizz]

I've ran syn in mine its whole life minus the factory fill w/no problems, so I couldn't comment on the switch. (I'm thinking about switching to dino) BUT...based on the maintanence schedule for the oil I would definitely look into the servicing of the the other fluids; transmission, diffs., transfer case and especially the coolant.

 

[smithph]

Stick with the High Mileage oils. I would do a few more short OCI's with Max Life, say 2.5K each, until it hit 85K. Then move to a High Mileage syn like Mobil 1 10w30 High Mileage (Walmart) or Full Synthetic Max Life if you can find it in your area. I do not see a need for any additives if its running strong etc.

 

[FrankN4]

Originally Posted By: smithph
Stick with the High Mileage oils. I would do a few more short OCI's with Max Life, say 2.5K each, until it hit 85K. Then move to a High Mileage syn like Mobil 1 10w30 High Mileage (Walmart) or Full Synthetic Max Life if you can find it in your area. I do not see a need for any additives if its running strong etc.

 

[KW]

Run a short OCI of about 3K then get the oil checked to see if it has an intake manifold leak. It likely does so after you get it fixed run what ever 5W30 you like in it. Amsoil 5W30 every with an OCI of every October looks good to me.

 

[StevieC]

Doesn't matter what you run as long as you change it at a reasonable interval because you can't kill these engines!

 

[MBCLK]

Originally Posted By: Superbuick96
Yeah a 28K OCI on dino. The previous owners fault. I Changed it at 76K, then after 900 miles, with Max Life blend.


may i ask what the 900 mile oil looked like when u changed it? dark?

what does the current fill of Max Life look like? dark? how many miles on it now?

 

[daves87rs]

Originally Posted By: smithph
Stick with the High Mileage oils. I would do a few more short OCI's with Max Life, say 2.5K each, until it hit 85K. Then move to a High Mileage syn like Mobil 1 10w30 High Mileage (Walmart) or Full Synthetic Max Life if you can find it in your area. I do not see a need for any additives if its running strong etc.

 

[NHHEMI]

Originally Posted By: smithph
Stick with the High Mileage oils. I would do a few more short OCI's with Max Life, say 2.5K each, until it hit 85K. Then move to a High Mileage syn like Mobil 1 10w30 High Mileage (Walmart) or Full Synthetic Max Life if you can find it in your area. I do not see a need for any additives if its running strong etc.



I agree mostly accept for the Mobil 1 part. Stick with the Maxlife Blend for a few more OC's at 2500-3000 miles. Then swap over to the Full Synthetic version. Wow, 15K, 18K and then two 28K OC's ON Conventional OIL.

WHAT was that guy thinking?

This is a perfect application, IMO, for some type of clensing additive to be used. I would personally add some Seafoam to the crankcase. It wouldn't hurt to add some to the gas tank as well and I would even do a vacuum induction treatment to clean your combustion chamber. Run the Seafoam in the oil for about 500 miles before your OC is due for the next 2 OC's. I would split the can over the 2 OC's. You could also go for the extra expense and time involved and do a full Auto-RX treatment. If ever there was an application that screamed for some type of oil additive this is it. 28K on Conventional. That guy was NUTS!

 

[Superbuick96]

In reply to the different questions and recommendations:

I did a full tuneup on the Blazer including other fluids..

Thank you for the recommendations, the Blazer will only be driven 3k mi. a year probably, it will be used to drive around my 2 retired racing greyhounds to the park mostly, and a 22 mi. highway drive to work once a week. But I plan on changing the oil every Spring and Fall, when I do my Ford Ranger. I put around 3k mi. every 6 months on the ford, use Mobil 1/Motorcraft filter. But yeah, keeping the OCI short for awhile on the Blazer shouldnt be a problem, Think I'll switch to a fully syn High Mileage oil for fall/winter. Is there reason to be leary of Valvoline, I see on the forum that Ashland says that Valvoline no longer produces they're own oil??
The Valvoline conventional, after 900 miles was filthy, but that was the first oil change in 28k. And so far after around 100 miles the Max L blend is clean.
Yeah 28k OCI on dino is crazy but it was my father in law,and he was elderly and sick. And NOONE touched his vehicle! So the Blazer was neglected.
As mentioned on here I was told by others the 4.3 is a tough engine.
Thank you for welcoming me, I'll be mostly a lurker, I cant get enough oil talk for some reason. This forum is addictive!

 

[Spector]

Having used both the Mobil 1 High Mileage and the MaxLife semi syn the problem with the Mobil 1 is it seems to increase any leaks or seepages whereas MaxLife (at least in my case) does the opposite. But that is my experience.

However, I would never use a High Mileage oil, regardless of brand unless there was an issue like seepages, leakes, burning etc. If the engine is operating fine you do not need a High Mileage oil, and with the driving schedule you outlined a true synthetic may be the way to go.

Like some said earlier though, any oil changed on a reasonable schedule will work and the engine will outlive the rest of the vehicle