81c3

So by this logic, all of us Vette owners should expect the results to be about a quart of oil used every 1000 miles or so, and we shouldnt be alarmed? Meaning, if I go 3000 miles between changes, the fact that I replenished the sump 3 out of 5 quarts is normal? If I go 5000 miles, 5 quarts out of 5 quarts? I dont think so!

Tom400CFI

Totally.


You don't need to be happy for me...you need to understand what is acceptable. a qt every 800 miles is totally unacceptable.



Right. OEM's have decided on a criteria that THEY feel is acceptable. My guess is that it is the most consumption that they could pass off on the public as "ok" and not get push back. However, when we compare that rate of consumption w/other vehicles that have received proper maintenance, we quickly realize that 1qt/1k is way outside of what is normal and average. If I had a car that consumed a qt every 1k, I KNOW that the dealer would tell me "it's normal"....but I'd also know that it is not normal, and I'd be pissed. That would be totally unacceptable.

Also note that a qt every 800 miles (the OP's situation) is 20% MORE consumption that than maximum allowable by the OEM's BS claim. That would also make the OP's situation...."unacceptable".



Again, the age has very little, to nothing, to do w/consumption on a properly maintained car. And engine is not a living, organic thing and as a consequence, it doesn't "age" -at least not in the realm of what we're discussing here. My cars get M1 oil change when it's due...other than that, I beat the wee out of 'em and they love it.



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kael

I appreciate all the thoughts and advice folks, I've heard and tried most of them, though 20w-40 seems a lot to me, but i know little. Specs are 5w-30, I bumped to 10w-30 since it's syn.

Anyway, #2 has black plugs and even though compression looks good, I had to use the rope trick to get the valves out, rest of the cylinders were fine. #2 exaust valve was one of three replaced. Cylinder looks fine from the top. So, I'm thinking worn rings. As a newbie, I didn't check when the heads were off, didn't know feeler strips would not cause damage. Plan is a leak test soon.

Only other problem I have, that I know about, is the dreaded code 36. Been chasing and no luck so far.

Anything I can do until I get a rebuild? It's going to be a few years and having her sit in the garage that long, well, I'd rather not.

Whaleman

I guess if you get to the point that you are positive a rebuild is necessary you have not much to lose by trying things like this. Dan

http://www.autozone.com/motor-oil-an...air/560524_0_0

kael

I have that on a shelf but not sure it would do any good or make it worse.

With a worn ring, is there any other option than rebuild? I've heard it's possible to pull the oil pan and change rings that way, I'd think that needs past experience to have a chance of success.

confab

Absolutely. The (ahem) "rebuilt" 355 in mine had the same problem. Stuck rings. (Multiple) Low compression on multiple cylinders.

I did rings, bearings and a cam right in the car.

It's easy. Plenty of room.

Pan comes off. No problem.

confab

PS: A piece of broken off ring makes a good groove cleaner.

Tom400CFI

IMO, no, if the cause is wear. Yes there are other options if the cause is stuck rings or carboned up oil rings. How has the maintenance been on the motor? How clean is it, inside? Those are big clues. A leak down test would be strong evidence too; if the leakage is low, past the rings, but you're burning oil past the rings, then it's not as likely that the oil rings (and cylinder bores) are worn, as they are, gummed up from poor PM.



Not quite. The pistons won't come out the bottom...so you need to pull more than the pan. If you pull the pan, and the heads, then you can remove the rod caps, and push the pistons out the top. Then you can replace the rings, hone the cylinders, put it back together and run the wee out of it...for a little while. If they cylinders are worn and barrel shaped, then this fix is a "10,000 mile rebuild". It's a short term improvement, but it won't last like a proper rebuild. I've done 'em though, back when I was PO, and it worked. Worked good enough for my purposes back then.

confab

This ^^^

I assumed this was obvious.

He's right. You have to pull more than the oil pan.

You have to strip it to a short block.

confab

You can fix it in the car, but the heads and the intake have to come off at a minimum.

Churchkey

If engine oil is changed @ 4K miles your operational cost is an additional 10.00 - 12.00$ for oil.

Oil consumption after a half-a$$ rebuild could be the same as what you have now & possibly worse.

High mileage engines need a fresh bore job to remove cylinder bore taper + a good hone for the proper cross hatch to bed the new rings in properly.

Good luck.

ghoastrider1

sometimes you cant really see oil (blue smoke) going out the exhaust pipe...during the day. I had a 67 ford pickup that this was the case. At night, when a car got behind me, I would look in the mirror and it looked like I was spraying for bugs .

kael

Like I said, not enough experience to chase replacing just the bad rings, certainly not honing. Maybe if I had an engine or two to screw up first.

How bad in $$$ would professional ring repair be versus full rebuild/crate?

Oh, update, she's got 60k miles right now, engine taken care of for 2 years, Seafoam a couple of times. No idea before that.

mtwoolford

Webster's Dictionary defines alarmed as "feeling a sense of danger, urgently worried, concerned or frightened" and for me personally, and maybe just me, I would not be "alarmed" with a thirty year old car that used a quart of oil every 800 miles;

Now when a wheel bearing failed and the *** end of my truck caught on fire at 2 in the morning on the freeway, I was "alarmed".

Tom400CFI

We've identified the problem!!



I think you'd be at ~80% of the cost of a rebuild. It would only be maybe hundred in parts (rings, bearing shells), but almost all of the labor is there for a rebuild. A "ring repair" would literally be pulling pistons, honing and re-ringing. New bearing shell b/c you're in there. Gaskets and seals too.



Only one plug is black? I wonder if you've got a bad intake gasket, and you're sucking oil through that? That would soot up a plug...it would consume oil...you'd still have good compression....

Can you find someone with the tools to help you do a leak down test?

ddahlgren

All the cylinders wen the same distance and for a street engine to have one oil soaked plug could be a lot of things. Intake gasket is very likely less possible is an injector that washed down one cylinder losing the seal. Bad intake valve guide is possible thing. Intake gasket would be a simple cheap try if all else checks out. A leak down tester will tell nothing about oil control rings.

In the easter egg land but not to be discounted is I have seem broken valve gear or ded cam lobe cause oiling so a quick look under the one valve cover is real cheap to cross that off.

Tom400CFI

A leak down test most certainly WILL tell something. I even clarified one thing that it would tell, earlier in the thread.


One of your suggested issues was an injector/washed down cylinder...right? How would that cylinder do in a leak down test? Poorly. That test would tell you something. If the leak down passes all cylinders with flying colors, then to ME, that would be a strong indicator that my cylinder bores/rings are fine, the problem is elsewhere. the OP needs to gather evidence about the condition of his engine. A leak down test is one of the BEST ways to accomplish that.


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kael

Leak down test, #2 was 20%. Karma, thank you.

Tom400CFI

Huh. Go figure, right?

Glad you got a conclusive result for you test...bummer it shows the need for a tear down. Did you identify where the leakage was?

kael

Tear down what?