Massive difference in oil consumption between 5W30 and 5W40

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What would cause the consumption to slow down after a while ? Do you think the different formulation/chemistry has more to do with the burning than the grade itself ?
It's blowing oil out the PCV until it gets to the midpoint on the stick.
 
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I'm not sure if anyone is interested but my brother has been using the straight Valvoline VR1 straight 50W racing oil. He has a Tracker with a Suzuki engine that makes a lot of timing chain noise and was burning a lot of oil between changes.

Since switching no more noise and it uses hardly any oil at all. We live in Southern CA so it never gets cold enough to give starting issues. I will say that the with the Fumoto valve that the motor has to be fully warmed up so it will drain out of the small hole.
Back in the early 90's I worked @ Kragen auto which later became Orileys. We had Valvoline racing in 30,40,50,60 and 20w50.

Sold tons of the thick stuff. Even me before I knew better. I ran sae 60 in all my stuff.
 
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I think when he says "blowing out" he means it is being sucked into the PVC valve not that it was actually exiting the engine, but I agree, the wording was awkward.

I drove flat-out the other day, 100MPH plus or minus 10 on wide-open highway for about 10 minutes, hard acceleration and cruise.. approx. 4000RPM sustained average. Had smoke coming from under the car when I was done. Noticed it when I pulled into the truck stop, I was reversing at a slow speed and I thought, did I just see smoke? and sure enough.. some smoke from under car. I suspect from the exhaust or trans. Opened up the hood.. saw from back part of engine too. I had recently "topped up" both my coolant and transmission fluid levels, so I suspect maybe some excess level was pushed out the vent of both the overflow bottle, and whatever vent valve on trans itself. Only fluid dripping was the water condensation from the AC, which was on.

Went in the truck stop, got my soda and pizza, drove the 5 more minutes to work at normal speed, 55MPH. No issues with the car, none at all, and it ran better the next day.

Two days later.. checked my fluids again, cold. I'm slightly over on the dipstick, not more than half a quart and my trans fluid looks good, almost like new as I have been drain and filling it twice in 10,000 miles not km. No issues.

I post all that, to say.. in an extreme use kind of scenario like this.. is the only way one would see oil on the back window if there was a leak from the rear main, catching the aerodynamics that then puts that oily mist all over the back of the car? (I did look hard at the back of my car to see if that is what happened, because I also know if there was an RMS leak, it would do that every highway trip. BTDT.) Or... Would the hard driving.. employ the PCV valve, engaging in crankcase ventilation, as you say.

No oil was burned, I am curious to see if that oil level goes down after a long OCI. It should be known I put Castrol Edge 0W-40 in there, and did not really have to add but a half quart when it appeared to be going low. Maybe I should read my dipstick better next time.

But. Would that be PCV operation? Or does just getting the engine/trans really really hot as per Italian Tune-Up like the car as my avatar also have its own ways of burning off oil, maybe sheer heat or forces exerted or ? (Blow-by produces smoke as well?)

I may have simply had a case of hot trans. Car runs better after this than before, so..
 
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Have you checked the cylinder head for leaks? It's notorious on those older Benz engines.
 
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OVERKILL

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I drove flat-out the other day, 100MPH plus or minus 10 on wide-open highway for about 10 minutes, hard acceleration and cruise.. approx. 4000RPM sustained average. Had smoke coming from under the car when I was done. Noticed it when I pulled into the truck stop, I was reversing at a slow speed and I thought, did I just see smoke? and sure enough.. some smoke from under car. I suspect from the exhaust or trans. Opened up the hood.. saw from back part of engine too. I had recently "topped up" both my coolant and transmission fluid levels, so I suspect maybe some excess level was pushed out the vent of both the overflow bottle, and whatever vent valve on trans itself. Only fluid dripping was the water condensation from the AC, which was on.

Went in the truck stop, got my soda and pizza, drove the 5 more minutes to work at normal speed, 55MPH. No issues with the car, none at all, and it ran better the next day.

Two days later.. checked my fluids again, cold. I'm slightly over on the dipstick, not more than half a quart and my trans fluid looks good, almost like new as I have been drain and filling it twice in 10,000 miles not km. No issues.

I post all that, to say.. in an extreme use kind of scenario like this.. is the only way one would see oil on the back window if there was a leak from the rear main, catching the aerodynamics that then puts that oily mist all over the back of the car? (I did look hard at the back of my car to see if that is what happened, because I also know if there was an RMS leak, it would do that every highway trip. BTDT.) Or... Would the hard driving.. employ the PCV valve, engaging in crankcase ventilation, as you say.

No oil was burned, I am curious to see if that oil level goes down after a long OCI. It should be known I put Castrol Edge 0W-40 in there, and did not really have to add but a half quart when it appeared to be going low. Maybe I should read my dipstick better next time.

But. Would that be PCV operation? Or does just getting the engine/trans really really hot as per Italian Tune-Up like the car as my avatar also have its own ways of burning off oil, maybe sheer heat or forces exerted or ? (Blow-by produces smoke as well?)

I may have simply had a case of hot trans. Car runs better after this than before, so..

You could have just heated the exhaust more than normal, burning off crap that was on it that hadn't previously got hot enough to burn off. My Jeep has been burning the factory coating off the exhaust for months now and I think it's basically gone now, but if I drive it REALLY hard, I can get it to smoke (the exhaust) as I get further back hotter than normal, but that's getting harder to do now too with there being next to nothing to burn off now. My wife's new Borla cat back has been the same experience on the truck, towing the trailer brought back the break-in smell as the truck got the exhaust hotter than it would unloaded.
 
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You could have just heated the exhaust more than normal, burning off crap that was on it that hadn't previously got hot enough to burn off. My Jeep has been burning the factory coating off the exhaust for months now and I think it's basically gone now, but if I drive it REALLY hard, I can get it to smoke (the exhaust) as I get further back hotter than normal, but that's getting harder to do now too with there being next to nothing to burn off now. My wife's new Borla cat back has been the same experience on the truck, towing the trailer brought back the break-in smell as the truck got the exhaust hotter than it would unloaded.

I did suspect almost the same since my car previously had a PO420 code (also a P0131) which after changing the O2 sensor that code never came back and after many thousands of miles of highway driving some of them flat-out I think that that issue is gone now.

There were also many short trips earlier that day so there was some heat before the run maybe that had something to do with it.

The oil is a nice perfect light brown color almost maybe one shade darker than honey because honey is yellow oil is more Amber Brown.

Also want to stipulate that different cars have different PCV systems.

However.. yes, baby revs so free. Love it.
 

M119

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Have you checked the cylinder head for leaks? It's notorious on those older Benz engines.
No seepage at all around the head gasket but some seepage around the rear main seal and oil pan gasket. Maybe Valvoline Maxlife 5w40 is my ticket.

JT20 : my cars always run better after an italian tune up and it stopped oil consumption some times !
 
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No seepage at all around the head gasket but but some seepage around the rear main seal and oil pan gasket. Maybe Valvoline Maxlife 5w40 is my ticket !

JT20 : my cars always run better after an italian tune up and it stopped oil consumption some times !

Oil isn't gonna fix it. Why not fix the actual problem rather than throwing different oil at it hoping for a miracle?
 

M119

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Oil isn't gonna fix it. Why not fix the actual problem rather than throwing different oil at it hoping for a miracle?
In fact i care very little about the seepage, i use different oils just depending on what i can get on sale and out of curiosity.
 

M119

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Catalytic converter mainly, already fried one thanks to an engine burning oil. The seepage doesn't need to be fixed, there's hardly a drop, it's just wet to the touch, it would be financially irresponsible. To me burning oil is a lot worse than a tiny leak.
 
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M119

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I would suggest filling the oil only to the midpoint on the stick. More than that just goes up in the PCV valve and into your intake. That's what I do on my MB's and even my Harley. The oil level never fluctuates. In the case of the Harley, there's no oil in the intake under the air cleaner. Give it a try.
I will see how it turns out now that the level is right in the middle. It would make my oil changes even simpler since it would only require one 5L jug. max=5.5L, min=4.5L in my car if i'm not mistaken.
 

M119

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It looks like oil consumption have been inexistent during the last 3000 kms ! But it usually starts burning oil again after 8000 kms. Now i know why my engine burns oil after an oil change and then completely stops past the first 2000 kms but i have yet to figure why it starts burning oil again after the 8000 kms mark. Sometimes i think about trying an HDEO like Shell Rimula 10w40, maybe it would stop consumption and i could go longer between intervals compared to a PCMO 5/10w40. What are your thoughts? The higher phosphorous content shouldn't be an issue if oil consumption is reduced but are these oils OK with E85? I know there's a brazilian BITOG user using a non gasoline rated HDEO with E100 but that's the only info i have on that subject. Would the high TBN be a good thing despite the lack of SN rating?
 
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