I have been searching thru the UOAs and found two. I think the search function is broke. Search for 350 and nothing, [censored]. Anyway, i have 93 4.3L(C1500), 01 vortec 4.3L(blazer), and 99 5.7L(suburban). If you have had UOA's done on any of these engines, could you please post your OCI, oil and generic results. I dont need to see the report, just tell me if it was good or bad. Also any habits with long life results would be helpful as well. I hear that these engines are pretty easy on oil and with PP should easily go 6k miles. I dont use my engines hard but on rare ocations. My vortec 4.3 sees many short trips. Wife works 7 miles from the house and drives there and back just about every day. I am not going to do 3k mile changes as i dont think that warranted. I also am not going to do 10k changes on dino either. I would like to settle in at 6k to 8k changes on synthetic. I am shooting for 300k miles for these engines. Heck my lowest mileage one is at 183k miles. To be fair, the 99 suburban has a rebuild that is less than 20k miles old. Im sure the truck will fall apart before i go thru this engine. My blazer has been on M1 synthetic most of its life and recently changed to PP, 7k miles is about its OCI. My C1500 has mainly been on 15w40 and its at 216k miles. The new rebuilt suburban engine is on QSHP 10w30. Thanks
GM 4.3L and 5.7L OCI?
- Thread starter jstutz
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as the 4.3 is a clone of the 5.7 with 2 cylinders cut off the block what is good for the 4.3 will be good for the 5.7 if used in the same conditions.
I'd use PYB or Castrol or any name brand at 5K changes. Do an occasional UOA on the 5.7 for the leaking intake manifold gasket syndrome
Steve
I'd use PYB or Castrol or any name brand at 5K changes. Do an occasional UOA on the 5.7 for the leaking intake manifold gasket syndrome
Steve
I used to feed my old 5.7l surburban Valvoline Maxlife/white bottle at 5K oci's and my current 4.3L lives off of chevron supreme and valvoline 5k oci's.
This is pure opinion, but I think that this engine can easy go on synthetic to 7500 miles. When I did the IMG on my 4.3 it was spotless.
This is pure opinion, but I think that this engine can easy go on synthetic to 7500 miles. When I did the IMG on my 4.3 it was spotless.
I've run 5-6k ocis on my 260k mile 96 C1500 4.3l V6.
Runs fine. Passes smog with no problems. 20+MPG.
No need for syn in this engine. I'd say less than 1% ever see it and look at all of them on the road with no problems.
Bill
Runs fine. Passes smog with no problems. 20+MPG.
No need for syn in this engine. I'd say less than 1% ever see it and look at all of them on the road with no problems.
Bill
bill, sorry for my ignorance, when you say less than 1% ever see it, do you mean synthetic oils? Sorry, just want to make sure. yea i thought about using up my synthetic and going to a good dino 10w30 with 5 k changes. Im one of those guys that when it starts pushing past 7K, i cant hardly relax. It is usually a strugle to make myself wait until 7500, even with synthetics.
The 4.3/5.7 will be quite happy on any respectable synthetic.
If they were mine, I would run PP for 6-7k oil changes depending on how long it took to rack up the miles. Our family 'Burbs have done well on this setup. You should have no issue hitting 300k.
If they were mine, I would run PP for 6-7k oil changes depending on how long it took to rack up the miles. Our family 'Burbs have done well on this setup. You should have no issue hitting 300k.
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Originally Posted By: jstutz
bill, sorry for my ignorance, when you say less than 1% ever see it, do you mean synthetic oils? Sorry, just want to make sure. yea i thought about using up my synthetic and going to a good dino 10w30 with 5 k changes. Im one of those guys that when it starts pushing past 7K, i cant hardly relax. It is usually a strugle to make myself wait until 7500, even with synthetics.
Yes syn oil is very rare used esp on a 4.3l V6. No need at all.
It gets a little too cold here for year round usage of 10w-30 but my 1996 has seen it from April till September for quite a few years.
Today's Conventional oils are so good and 5w-30 has improved I just run it year round in everything I change oil in. (except my Dad's Honda Powered Vue which sees 5w-20 conventional oils)
If you change oil every 5k unless it sees 1 mile trips every time you'll be fine!
Take care, bill
bill, sorry for my ignorance, when you say less than 1% ever see it, do you mean synthetic oils? Sorry, just want to make sure. yea i thought about using up my synthetic and going to a good dino 10w30 with 5 k changes. Im one of those guys that when it starts pushing past 7K, i cant hardly relax. It is usually a strugle to make myself wait until 7500, even with synthetics.
Yes syn oil is very rare used esp on a 4.3l V6. No need at all.
It gets a little too cold here for year round usage of 10w-30 but my 1996 has seen it from April till September for quite a few years.
Today's Conventional oils are so good and 5w-30 has improved I just run it year round in everything I change oil in. (except my Dad's Honda Powered Vue which sees 5w-20 conventional oils)
If you change oil every 5k unless it sees 1 mile trips every time you'll be fine!
Take care, bill
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