I've got a '79 GMC k1500/350/465/205. I bought this for the snowplow on it to plow snow out of the yard. The old girl runs good and doesn't leak anything. It really burns oil bad, quart in 40 miles and constant blue smoke. I would like to get through this winter before I rebuild or replace. Is there anything that can slow the oil consumption and thin out the blue cloud some?
CK5
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Burning lots of oil
- Thread starter 1980
- Start date
Quart in 40 miles???
If it doesn't leak at least some of that, you need to mix some Malathion with your oil and hire it out as a bug fogger.....
I assume you have changed the oil and put in some 20W-50.
I would pull the plugs and see if one is sooted up more than the others.
With that kind of oil use, if it were worn rings I doubt it would have enough compression to start.
I am thinking maybe a bad intake gasket, or someone has hooked a vacuum line to the dipstick hole......
If it doesn't leak at least some of that, you need to mix some Malathion with your oil and hire it out as a bug fogger.....
I assume you have changed the oil and put in some 20W-50.
I would pull the plugs and see if one is sooted up more than the others.
With that kind of oil use, if it were worn rings I doubt it would have enough compression to start.
I am thinking maybe a bad intake gasket, or someone has hooked a vacuum line to the dipstick hole......
79bonanza
1/2 ton status
toasted rings/ bad valve stem seals
4xcrazy
3/4 ton status
I can tell you from experiance, 20/50 weight oil, in that cold of a climate he's in, or soon will be, that motor WILL NOT like starting or running for a bit until it's warmed up.
I made that mistake when in Arizona, lived in Phoenix, always warm n hot, used the thicker oil to help control leaky valve seals, went to Flagstaff for a few months, when it got down to single digit temps outside, it was a slow cranking beast. Also forgot to "winterize" the cooling system, it froze up once when i went to go to work, 220 on the temp gauge, radiator cold
yeah, quart in 40 miles? i'd be doing a compression check.
I made that mistake when in Arizona, lived in Phoenix, always warm n hot, used the thicker oil to help control leaky valve seals, went to Flagstaff for a few months, when it got down to single digit temps outside, it was a slow cranking beast. Also forgot to "winterize" the cooling system, it froze up once when i went to go to work, 220 on the temp gauge, radiator cold
yeah, quart in 40 miles? i'd be doing a compression check.
That rings on that motor are probably well past gone, that is a ridiculous amount of fuel consumption. So plan on a used/new motor sometime in the near future.
Failing that, go to any parts store and buy a can of "Restore". You'll hear and see all kinds of positive/negative opinions about it but it's cheap and I bet it will significantly reduce your oil consumption. What do you have to lose?
Failing that, go to any parts store and buy a can of "Restore". You'll hear and see all kinds of positive/negative opinions about it but it's cheap and I bet it will significantly reduce your oil consumption. What do you have to lose?
Thanks guys, I am running 20-50. I have an old dip stick heater I can use in cold, but have not needed it yet. A neighbor suggested gear oil. I may try restore or lucas stuff. I know there is no miricle juice, just get embarrased with all the smoke and I hope to baby about 5 months out of this motor. I'm also a little afraid if I fix one thing, all the other tired parts will suddenly want fixed too!
PS- Where did all the $300 old running 350s go?
PS- Where did all the $300 old running 350s go?
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I'd steer clear of "Restore",I have seen insides of engines that had that stuff in it,every one tossed a bearing shortly after it was added,and the oil looked like someone poured a quart of aluminum paint in it...
I'd use Lucas or similar oil fortifiers like STP or Motor-Medic,Bardahl "Stop-Smoke",etc..NOT some "miracle" engine rebuild in a can crap!--if your going to do that,you may as well order those magic pellets and goop from J.C. Whitney that promises to "replate worn parts as you drive"!..
...
Yes,thicker oil might present starting problems in frigid weather,but also might be needed just to get enough compression to get it running too...I had a '67 Impala with a super worn 283,I used 20W-50 and two qts. of Motor Medic in it to make it not smoke screen so bad I'd get pulled over--to get it started in winter I put a second battery in it and left the two of them hooked up in paralell so it would have plenty of cranking amps..
You may want to inspect the PCV valve and the hoses,see if its getting good vacuum to the PCV and that the valve covers have a proper breather--I have seen may aftermarket valve covers that had no provision for a breather,and without one the PCV valve will suck oil like crazy and it will be burned ---I have seen a few small blocks that blew intake gaskets and sucked oil in from the valley area also..bought two "junk" 350's that smoked like crazy,all that was wrong was the valve covers weren't stock and plumbed up correctly,the other had a bad intake gasket..
I'd use Lucas or similar oil fortifiers like STP or Motor-Medic,Bardahl "Stop-Smoke",etc..NOT some "miracle" engine rebuild in a can crap!--if your going to do that,you may as well order those magic pellets and goop from J.C. Whitney that promises to "replate worn parts as you drive"!..
...Yes,thicker oil might present starting problems in frigid weather,but also might be needed just to get enough compression to get it running too...I had a '67 Impala with a super worn 283,I used 20W-50 and two qts. of Motor Medic in it to make it not smoke screen so bad I'd get pulled over--to get it started in winter I put a second battery in it and left the two of them hooked up in paralell so it would have plenty of cranking amps..
You may want to inspect the PCV valve and the hoses,see if its getting good vacuum to the PCV and that the valve covers have a proper breather--I have seen may aftermarket valve covers that had no provision for a breather,and without one the PCV valve will suck oil like crazy and it will be burned ---I have seen a few small blocks that blew intake gaskets and sucked oil in from the valley area also..bought two "junk" 350's that smoked like crazy,all that was wrong was the valve covers weren't stock and plumbed up correctly,the other had a bad intake gasket..
4xcrazy
3/4 ton status
if you want to run a thick oil, don't use gear oil, yes it's thick, but not really made for that application. I have seen, and used 50 and 60 weight racing oil sold at alot of parts store, usually i have only used a quart or two to do as you are needing, to thicken the oil up some in the hopes of helping with a oil burning issue. Also quiets the lifters quite abit too 
Does it have any power at all? I have seen engines that probably burned that much, but they were very weak, and usually knocked some.
Again, I would pull the plugs at a minimum to see if the oil burning is even among all the cylinders.
While you have them out, you are halfway to a compression check if you borrow a gauge.
But either way pull the plugs and look.
And BTW Diesel4Me, darn it, I was going to bring up the Pellets.
You beat me to it.
Again, I would pull the plugs at a minimum to see if the oil burning is even among all the cylinders.
While you have them out, you are halfway to a compression check if you borrow a gauge.
But either way pull the plugs and look.
And BTW Diesel4Me, darn it, I was going to bring up the Pellets.
You beat me to it.
If it runs some what okay but smokes bad, it could be a stuck ring. You will be able to tell by pulling the plugs.
I've only noticed a lack of power when pulling a horse trailer or against a heavy wind. Certainly not a power monster, but gets around fine for a 30yr old. I changed the plugs about a month ago when it started running very badly. Three were clogged and in bad shape. I bought it about a year ago and that was the first plug change on it for me. I just recently found my old compression gauge and will check that out. Is the best method to test compression to pull a plug, insert gauge, turn the engine over, read and move to next plug? Would a leak in the intake cause it to miss? It idles and runs fine.
Thanks
Thanks
4xcrazy
3/4 ton status
yes on the compresion check, also remove the main power wire feeding the coil so it has no juice to fire the engine
chulisohombre
1/2 ton status
i was thinkin that and seen your post before i could put it haha.id do the compression from cold to see just how bad the rings are.turn the engine over at least 4 or 5 times to get a final reading after the engine moves the oil around.id also write down the numbers.each cylander should have at least 100 psi to run sufficient.and also no cylander should be less than 20 percent from the other cylanders.so 120 on 6 and 85 on 2 and you know the rings are shot on those cylanders.if the valve seals are completely shot or missing,the oil will be dumping into the cylanders also every time the rocker moves the valve.bad pcv will suck oil right into the intake also from the breather tube going to the air cleaner.pull the pcv and make sure it is still moving and pull the tube off and see if it has oil in it.a lil wont matter but if its full you should see it up into the air cleaner also.every time you gas it past idle the pcv is supposed to close and if its bad it will suck oil from the valve cover but i dont think a quart every 40 miles.mines a quart every 200 miles but it is my valve seals leaking.yes on the compresion check, also remove the main power wire feeding the coil so it has no juice to fire the engine
zombie1969
1/2 ton status
Checking pcv good idea.Also have seen a few that the intake was tightened too much and damaged the gasket causing it to suck oil directly from the lifter valley.That much oil I'm leaning towards the gasket being too tight.Don't run 20 50 oil it can cause drain back problems in the heads and starve the pump and cause the oil to go over the valve seals straight down the guides.Delvac 15 40 diesel engine oil works good.
4xcrazy
3/4 ton status
Sorry, but i DEFINATELY, would not run a 15/40 oil in that motor with the high mileage and most likely dirty condition. That oil has alot of detergents in it and will loosen everything up in there.
I tried it personally in a car i owned with over 100k miles, got the oil for free, within 1500 miles, it had wiped the cam and lifters out. Kinda why i don't even use it at all in ANY gas engine i own.
Using full synthetic now, but the motor in the Burb is brand new, but i also switch to full synthetic in the parents rides, moms truck with well over 200k miles and it's still going strong, oil is staying nice as well, dads Aveo had over 140k miles, his still working good and clean as well.
Filters is where it's at too if you switch oils around, NOT using a Fram filter.
I tried it personally in a car i owned with over 100k miles, got the oil for free, within 1500 miles, it had wiped the cam and lifters out. Kinda why i don't even use it at all in ANY gas engine i own.
Using full synthetic now, but the motor in the Burb is brand new, but i also switch to full synthetic in the parents rides, moms truck with well over 200k miles and it's still going strong, oil is staying nice as well, dads Aveo had over 140k miles, his still working good and clean as well.
Filters is where it's at too if you switch oils around, NOT using a Fram filter.
zombie1969
1/2 ton status
Sorry to hear about your cam but I think your blame is misplaced.I had a surplus of something like 300 gal I got for free and have been using it in all my cars for years.My s15 Jimmy with 190k when I sold it and it still runs great with some bad valve seals/both my Grand Am's and my sb 406 from day 1 that has 30-40k on it and runs prefect.Its rec for diesel/high mileage conventional and high performance gas engines.Some interesting reading on the stuff.
http://thelubricantstore.com/Custom.../specpages/MOBIL-DELVAC-1300-SUPER-15W40.HTML
http://thelubricantstore.com/Custom.../specpages/MOBIL-DELVAC-1300-SUPER-15W40.HTML
4xcrazy
3/4 ton status
well, whatever, nothing else changed on that motor, and it had run perfectly up until i used 15/40wt oil, when i dropped the oil out, it was the consistancy of water and black as black could be. The cam & lifters were replaced, oil changed with regular oil it had been previously run with all it's life (after the break-in) and it never gave another problem again for the next several years up until i traded it away for a newer car.
this particular multi-weight oil was specifically designed for Diesel engines, and even though it works in gas engines, it's not a highly recommended oil for them, if it was, why wouldn't all the car makers now running full synthetic, choose to run 15/40 over their 5/30 or 10/30 syn oil? it's obviously cheaper,, supposedly performs the same as a syn oil.
Again, i realize alot of people on here are running this 15/40 oil, just my opinion that's it's not the preferred stuff to be running in a gas engine..
Hell, synthetics have been on the market for quite awhile now, and i JUST barely switched over to those in the past couple of months, skeptical, especially with the higher mileage vehicles i have it in now, but i'm keeping a close eye on it's performance and whatnot. So far, it's working out fine.
this particular multi-weight oil was specifically designed for Diesel engines, and even though it works in gas engines, it's not a highly recommended oil for them, if it was, why wouldn't all the car makers now running full synthetic, choose to run 15/40 over their 5/30 or 10/30 syn oil? it's obviously cheaper,, supposedly performs the same as a syn oil.
Again, i realize alot of people on here are running this 15/40 oil, just my opinion that's it's not the preferred stuff to be running in a gas engine..
Hell, synthetics have been on the market for quite awhile now, and i JUST barely switched over to those in the past couple of months, skeptical, especially with the higher mileage vehicles i have it in now, but i'm keeping a close eye on it's performance and whatnot. So far, it's working out fine.
True,diesel rated oil has a much higher detergency and will loosen sludge deposits in a old poorly maintained engine and possibly cause damage,but as long as the engine was not all sludged up,you'll hurt nothing using diesel oil in a gas engine--it exceeds ALL specs for gasoline engines and if used from the start,will keep them in excelent condition...the viscosity isn't that big an issue really,its only slightly thicker than 10W-40 and probably thinner than 20W-50 is..I have used 15W-40 in many of my V8 and 6 cylinder engines with no problems whatsoever,so has my brother,who got 55 gallon drums of it at work and they used it in all the company vehicles without any issues..I would not reccomend it for a 4 or V6 modern engine designed to use 5W-30 though,but on a higher milage engine I bet it would reduce oil consumption and improve compression..I've used 15W-40 in many of my small engines on tractors and mowers with no ill effects too,and they consume less of it than other weights..
I would dare say more problems have arisen from using synthetics in old engines run on petroleum oils for a long time,than a diesel rated oil...diesel oils also have more of the zinc required to extend cam & lifter life on flat tappet engines,that has been removed from many "passenger car" oils too..
Using an oil with a higher flash point will reduce burning...synthetic has higher flash points than dino oil does,and straight weight oils have higher flash points than multi-weight oils do,and will not burn off as rapidly..
What I usually do on an old engine that smokes,is change the oil to 10W-30 and add a quart of Marvel Mystery Oil to the crankcase,and run it 500 miles,but first I pull off a valve cover and see if its all sludged up around the rockers--if it is ,it might not be a good idea to "flush" it out as it might allow dirt to pass thru the bearings and cam lobes..more than one "smoker" I put the Marvel Oil in and ran awhile,didn't smoke or consume anywhere near as much oil afterwards..if its sticking rings,Marvel will eventually loosen them up if they are going to free up at all...its possible the truck might have sat for long periods between snowfalls,and got little if any maintenence,then got whipped when it did snow out--that is a good way to get the rings all caked up and make them stick..
I would dare say more problems have arisen from using synthetics in old engines run on petroleum oils for a long time,than a diesel rated oil...diesel oils also have more of the zinc required to extend cam & lifter life on flat tappet engines,that has been removed from many "passenger car" oils too..
Using an oil with a higher flash point will reduce burning...synthetic has higher flash points than dino oil does,and straight weight oils have higher flash points than multi-weight oils do,and will not burn off as rapidly..
What I usually do on an old engine that smokes,is change the oil to 10W-30 and add a quart of Marvel Mystery Oil to the crankcase,and run it 500 miles,but first I pull off a valve cover and see if its all sludged up around the rockers--if it is ,it might not be a good idea to "flush" it out as it might allow dirt to pass thru the bearings and cam lobes..more than one "smoker" I put the Marvel Oil in and ran awhile,didn't smoke or consume anywhere near as much oil afterwards..if its sticking rings,Marvel will eventually loosen them up if they are going to free up at all...its possible the truck might have sat for long periods between snowfalls,and got little if any maintenence,then got whipped when it did snow out--that is a good way to get the rings all caked up and make them stick..
