Best oil choice for high mileage Chevy S10

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honestly, by the time the old Z-motor hits 150K or more, any oil that is still in there after 3-4K miles is good.

I would spend nothing more than walmart super tech on sale and check it.

if you have sludge (you dropped the pan to verify this?) then you have the expected intake manifold seepage at the rear crossover port. spend an afternoon and change this out and be done with it.

if the body is good and none of the bushings or mounts are shot, consider a reman 4.3. every once in a while advance runs a special from 'recon' on them for cheap, with a warranty.
 
ok I just looked at your pic link, that 'sludge' problem, aint sludge at all but rather ash/varnish buildup - common with chevies when they restricted the oil flow to the heads, it would actually cook in place and build up.

since you dont know how it was treated the first 20 years of its life, remove the covers, use a shop vac and scrape as much as you can, run a can of rislone or bg motor flush or whatever before the next change. it will clean what it needs to clean out.

and fwiw - what you see there is not indicative at all of what the actual oiled surfaces look like. I have taken apart dozens of motors infinetely worse than that, that could be returned to service with simply a set of std. size bearings and no other work.
 
Originally Posted By: QuadDriver
ok I just looked at your pic link, that 'sludge' problem, aint sludge at all but rather ash/varnish buildup - common with chevies when they restricted the oil flow to the heads, it would actually cook in place and build up.

since you dont know how it was treated the first 20 years of its life, remove the covers, use a shop vac and scrape as much as you can, run a can of rislone or bg motor flush or whatever before the next change. it will clean what it needs to clean out.

and fwiw - what you see there is not indicative at all of what the actual oiled surfaces look like. I have taken apart dozens of motors infinetely worse than that, that could be returned to service with simply a set of std. size bearings and no other work.

When did chevy restrict the oil flow to the heads?

I have a 93 c/k with the 4.3 and it gushes oil to the heads. It was a mess the last time I adjusted the valves ( waste of time. They didn't need any adjusting ) I used the engine running technique to adjust them. And oil was gushing up nicely through the pushrods. It made a mess.

This engine hasn't gotten regular OCI. I change 4 times a year and my valve rockers are squeaky clean.
 
yeah sbcs and the 4.3(same engine just -2 cylinders) have great flow to the rocker arms. thats why we put oil restricters in with solid cams, to keep more pressure on the crank and rods.
 
Originally Posted By: highmilegeguy
When did chevy restrict the oil flow to the heads?



85 for the 4.3 v6, 86 for the v8s during the redesign. visualize for a moment the SBC oil path( hint: it aint 'priority main'), in days of old, if you had non chamfered oil returns, you could store a qt in each head at prolonged hi rpms. If you have a 5qt sump and a 1qt oil filter/pump/passage volume, that dont leave much for other 'things'
 
Originally Posted By: Covert24
sure looks like sludge in person to me but never the less... Would an engine flush be able to clean some of this out or is breaking out the shopvac the only solution?


lets say an engine flush DID break loose the chunks. (it will never dissolve the carbonized lumps). where they gonna go? where they gonna go that it wont be bad, 'ver 'ver bad.....
 
I'll definitely keep that in mind. One of these days when I'm not swamped with work and school I'll get to dropping the pan and doing a nice scrape job on the heads.

I've been emailing the guys at Auto-RX about the situation and they have been more than helpful as well as nice about the whole thing. Once I get paid this week I'll be ordering some of that and proceed with the ARX process. Really looking forward to the results.

I'll be posting back with pictures before, during, and after in the next few weeks to document the results. After I finish this whole shpeal I'll be switching to probably the rotella t6 5w-40 Or the t5 10w-30 flavor. If for some reason I decide against the rotella, I'll continue using the Penn Ultra 5w-30. We shall see
smile.gif
 
Originally Posted By: highmilegeguy
Originally Posted By: QuadDriver
ok I just looked at your pic link, that 'sludge' problem, aint sludge at all but rather ash/varnish buildup - common with chevies when they restricted the oil flow to the heads, it would actually cook in place and build up.

since you dont know how it was treated the first 20 years of its life, remove the covers, use a shop vac and scrape as much as you can, run a can of rislone or bg motor flush or whatever before the next change. it will clean what it needs to clean out.

and fwiw - what you see there is not indicative at all of what the actual oiled surfaces look like. I have taken apart dozens of motors infinetely worse than that, that could be returned to service with simply a set of std. size bearings and no other work.

When did chevy restrict the oil flow to the heads?

I have a 93 c/k with the 4.3 and it gushes oil to the heads. It was a mess the last time I adjusted the valves ( waste of time. They didn't need any adjusting ) I used the engine running technique to adjust them. And oil was gushing up nicely through the pushrods. It made a mess.

This engine hasn't gotten regular OCI. I change 4 times a year and my valve rockers are squeaky clean.




did you use a vacuum gauge too? adjust to the highest vacuum.
 
Originally Posted By: Covert24
I'll definitely keep that in mind. One of these days when I'm not swamped with work and school I'll get to dropping the pan and doing a nice scrape job on the heads.

I've been emailing the guys at Auto-RX about the situation and they have been more than helpful as well as nice about the whole thing. Once I get paid this week I'll be ordering some of that and proceed with the ARX process. Really looking forward to the results.

I'll be posting back with pictures before, during, and after in the next few weeks to document the results. After I finish this whole shpeal I'll be switching to probably the rotella t6 5w-40 Or the t5 10w-30 flavor. If for some reason I decide against the rotella, I'll continue using the Penn Ultra 5w-30. We shall see
smile.gif



Sounding like you've got things in order. Keep it up!
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Originally Posted By: lexus114
i like my way much better.


ok how are you doing this? you want a higher vacuum reading, make the valves open late, way late, back off the lash to the point where the valve train is in jeopardy. it wont make power, but it will suck the guts out of your vacuum gauge.
 
huh?? all you do is adjust them individualy,and watch the guage. simply adjust to the highest reading. do this for each one while the motor is running. always worked great for me on chevy`s. i dont know what your talking about though.
 
Originally Posted By: lexus114
huh?? all you do is adjust them individualy,and watch the guage. simply adjust to the highest reading. do this for each one while the motor is running. always worked great for me on chevy`s. i dont know what your talking about though.


I have never seen any printed procedure, nor ever performed one using a gauge. And if I did, like I said, if you delay the valve opening the vacuum will be higher.

But the rationale for the adjsutment procedure I spoke of: you want to depress the plunger in the hydraulic lifter about half its running depth, which is about .060. the stock chevy studs/nuts are 3/8-24NF thread.

this means 24 turns per inch. 1 turn is therefore appx .042 inch. 1/2 to 3/4 turn would be a .021 to .0315 inch depression. lower for softer valves and more low end, higher for more top end.

If this was a mechanical cam, you have to use a feeler gauge and I dont see it happening while the engine is running.

if you fail to set the hydraulic preload at all, meaning a clattering gap, you can and will break the keeper for the plunger spring. you dont want this keeper cirulating thruout the engine...
 
Alrighty guys. Little update here. Got my 2 bottles of auto-RX in the mail today and will be installing it when I get outta work at around 2. Will be taking the driver side cover off for some before pics. Also picked up a bottle of Gunk HM motor flush but will only be using 1/2 the bottle and idle it for about 10-15 minutes before I drain my current oil. Definetely not trying to use te whole bottle of the stuff, just enough to get some residiual [censored] out.

Now for my procedure once I get home:

1. Pull driver side valve cover off and take a picture
2. Reinstall VC and add 1/2 gunk flush
3. Idle for say 15 minutes and drain oil for 1 Hr
4. Pull VC off and take a picture
5. Reinstall VC and switch out the oil filter with my new Puralator Classic
6. Add 3 qts of the Valvoline Conventional 5w-30
7. Add one bottle of Auto-RX
8. Add rest of Valvoline 5w-30 until full.

That's about it for today and will be running the ARX for 3k miles, changing the filter out at the halfway point (1500 miles).

Now keep in mind my current oil that's in the truck right now is PU 5w-20 with 1qt of MMO and a bottle of 6cyl restore. Hence my reasoning for the gunk motor flush..

I will be cutting my current filter open as well as all the filters to come to check residue content as well as taking VC off. Pictures will be plentiful
smile.gif
 
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