Vortec 5.7l oil consumption.

[Pinger]

I'm seeing oil consumption higher than expected for a low mileage 1999 Vortec 5.7l running with 10W/30.
On another thread there's one poster who says changing to a xxW/40 cuts consumption - eventually ( a gradual process, why not immediate?).
Trying to figure if I have an internal problem or is this just what these engines do. I've pulled the plugs and the worst I'm seeing is a very light brown/tan on the porcelain of some of them (and only on one side of a plug).

So I'm throwing out the following questions to try and find out what's 'normal' for these engines.

A. What consumption do you have in miles/quart?
B. What grade of oil do you run?
C. What mileage has your engine covered?
D. What colour shows on your spark plugs?
TIA.

 

[letitsnow]

Mine doesn't use any oil between changes, but it only has 7,000 miles on it. The old motor had 217,000 miles, and didn't burn oil either. I switched that motor to 5w40 (because I used that in other vehicles) and a rod started knocking shortly after that. Probably a total coincidence, but who knows. I run 5w30 in the new motor...

 

[Nad_Yvalhosert]

The "other poster", his user name is Nad Yvalhosert. He uses high mileage 10/40. The high mileage oil has an additive called "seal swell". It's formulated to, over time, slow down external leaks by swelling gaskets, and plugging/filling minute variations in metal surfaces. But it's not an instant process. It takes time to work. Also, the thicker petroleum based medium (the actual oil) is thicker and doesnt easily flow through loose piston ring gaps.
Sorry, there's no instant gratification in life.
Remember, it took 100ish thousand miles and over 20 years to get your engine to the state it's in now. There's no magic Star Trek hypospray that'll instantly cure the oil consumption.

 

[df2x4]

A.) None, in either of my '97s. Sometimes they drip a little but they never read low on the stick, and I frequently go over a year between oil changes.

B.) Pennzoil conventional 5W-30.

C.) About 150K miles on each truck, about 3K miles per year recently.

D.) No idea, haven't pulled plugs in years.

 

[Supercharged111]

I burn probably 2 quarts every 5,000 miles. Has done so for the last 100,000 miles or so, doesn't seem to be getting better or worse. I know the towing I do is partly to blame, plugs are tan IIRC. How much are you using Pinger? I use M1 0W40 synthetic.

Edited to add my truck has 279,000 miles on it (the 1500). And that I did valve seals 50,000 miles ago in 2015.

 

[Pinger]

I burn probably 2 quarts every 5,000 miles. Has done so for the last 100,000 miles or so, doesn't seem to be getting better or worse. I know the towing I do is partly to blame, plugs are tan IIRC. How much are you using Pinger? I use M1 0W40 synthetic.

1.2l (1.27 USQrts) added over 1100 miles.
No leaks that could account for it. Suspected a broken oil control ring or break in the inlet manifold gasket and went looking for an oiled plug as verification but they're all the same, white/light brown/tan (one one of their sides) so if it's burning oil I'm guessing it's uniform across all cylinders.

PCV is fine. Can an inlet manifold gasket(s) leak and burn oil across all (or at least one bank) cylinders?
When I had the sump off earlier this year, the crosshatching was still visible on the bores (only done 43,000 miles).
It has had a series of inlet backfires and a crankcase explosion - hence me looking for individual cylinder damage. The inlet manifold gasket would be susceptible and they've been shot at from both sides! Inlet manifold itself must have had a shock across the valley floor also (from both sides). If it's drawing enough (1 litre/1000 miles) oil there, would the vacuum be detectable in the crankcase (with the PCV isolated)?

If this level of consumption was concentrated on one or two cylinders - wouldn't it show on their plugs?

 

[jjester6000]

1.2l (1.27 USQrts) added over 1100 miles.
No leaks that could account for it. Suspected a broken oil control ring or break in the inlet manifold gasket and went looking for an oiled plug as verification but they're all the same, white/light brown/tan (one one of their sides) so if it's burning oil I'm guessing it's uniform across all cylinders.

PCV is fine. Can an inlet manifold gasket(s) leak and burn oil across all (or at least one bank) cylinders?
When I had the sump off earlier this year, the crosshatching was still visible on the bores (only done 43,000 miles).
It has had a series of inlet backfires and a crankcase explosion - hence me looking for individual cylinder damage. The inlet manifold gasket would be susceptible and they've been shot at from both sides! Inlet manifold itself must have had a shock across the valley floor also (from both sides). If it's drawing enough (1 litre/1000 miles) oil there, would the vacuum be detectable in the crankcase (with the PCV isolated)?

If this level of consumption was concentrated on one or two cylinders - wouldn't it show on their plugs?

A quart every 1100 miles is not too bad, it just sounds like bad valve seals to me. Does it smoke on cold starts? If so that is probably valve seals.
(When they go bad, the consumption is usually even acrossed all the cylinders)

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If it were a broken ring, it would be like the 250 i6 in my '74; which is catostrofically worn out, so I go through a quart of 20w50 every 30-40 miles. Since I'm running spark plug antifowelers, it leaves a nice smoke screen and still runs like a champ as long as I keep oil in it.
(I am about to put a new motor in it)

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My '98 seems to have burned half a quart after 1300 miles (which isn't bad for 200k).

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[WhiskeyTango93]

A quart every 1100 miles is not too bad, it just sounds like bad valve seals to me. Does it smoke on cold starts? If so that is probably valve seals.
(When they go bad, the consumption is usually even acrossed all the cylinders)

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If it were a broken ring, it would be like the 250 i6 in my '74; which is catostrofically worn out, so I go through a quart of 20w50 every 30-40 miles. Since I'm running spark plug antifowelers, it leaves a nice smoke screen and still runs like a champ as long as I keep oil in it.
(I am about to put a new motor in it)

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My '98 seems to have burned half a quart after 1300 miles (which isn't bad for 200k).

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Any of you guys changed your PCV valve out? they're about $4.....

 

[Pinger]

A quart every 1100 miles is not too bad, it just sounds like bad valve seals to me. Does it smoke on cold starts? If so that is probably valve seals.
(When they go bad, the consumption is usually even acrossed all the cylinders)

All that comes off the tail pipes on cold start is a smell of LPG (propane) as it goes rich before the O2 sensors are hot enough to rein it in.

My '98 seems to have burned half a quart after 1300 miles (which isn't bad for 200k).

Twice that on a motor that has done a fifth of that mileage definitely has something amiss.

Any of you guys changed your PCV valve out? they're about $4.....

Brand new a few months back.

 

[thegawd]

my Burbs 5.7 has 330 000 original miles and the engine is 100% original and untouched besides the usual exterior failures... intake gaskets, ect n all that was done prior to me getting her 8-9 years ago, then a full tune up by me shortly there after.

A. A minuscule uncalculable amount. I always check my fluids once a week or more, a habit my Dad drilled in me. I might top it up by 1 quort in total in
between oil changes. it dosent burn it, it drips a little but not enough to hit the ground. Ontario dosent have emissions testing anymore but whenever this truck was tested it had a very clean anylsis. the techs were always suprised and the test didnt take long to complete.


B. 5w30 quakerstate advanced durability. it is good oil according to the Petroleum Quality Institute of America. I check all the fluids I buy here first. and I dont care to debate synthetic vs conventional blah blah blah.... I'm a dont fix it if it ain't broke kinda guy. newer motors of course.... it is not.

http://www.pqiadata.org/QuakerState5W30712015.html

C. original 330 000 miles. that's 531 000 Kms, trucks from Texas.

D. I haven't looked at my plugs in about 6 years when I replaced them. they are iridium tipped ac delco.

Cheers!

Al