consumption new engines

[wjli]

trying to understand a little better why some engines consume oil while others dont, especially when it comes to two of the same engine and they are new/low mileage engines.

why would one consume oil of a given weight (the recomemended weight) while another of the same engines has zero consumption while using the same exact oil ?

Is driving style the desiding factor?

where is the oil going, past the rings, past the valves, both ?

is there a recommended quality to look for in an oil to limit/stop consumption? or would weight have to be adjusted?

 

[SteveSRT8]

I can only tell you that here in our fleet we have zero burners.

All are broken in HARD, warm it up and get your foot in it!

Low tension rings are the culprit, rings break in quickly and need high cylinder pressures to push them outward into the cylinder wall...

 

[rjundi]

You only hear of oil burners the most on internet. Not the other likely 95-99% of folks who don't have problem.

People don't seek out a forum to say my engine does not have a problem....They look for answers, company(for their misery) and outlets for frustrations.

IMHO all makers have ones that consume oil, just the minority.

 

[Olas]

X2 on the break in procedure mentioned above.. granny it and the rings wont seat = consumption issues.
Conversely 'getting on it' seats them more thoroughly and you wont consume until pcv/stem seals let you down
HTH

 

[Cooper]

Originally Posted By: SteveSRT8
I can only tell you that here in our fleet we have zero burners.

All are broken in HARD, warm it up and get your foot in it!

Low tension rings are the culprit, rings break in quickly and need high cylinder pressures to push them outward into the cylinder wall...


+1!

 

[Rand]

Originally Posted By: SteveSRT8
I can only tell you that here in our fleet we have zero burners.

All are broken in HARD, warm it up and get your foot in it!

Low tension rings are the culprit, rings break in quickly and need high cylinder pressures to push them outward into the cylinder wall...


and then you just have engineering fail where they changed ring designs 4x in 3 years.

Enter the subaru fb25.

 

[Clevy]

Add another for break in.
As Steve mentioned,low tension rings are the reason. They seal when there is combustion pressure.
That is why chev had an oil consumption issue with their afm engines. The cylinders that got shut off didn't have any combustion pressure and oil would get past the rings.
They've solved the issue.

 

[440Magnum]

Break-in is one cause. But I think a lot of the aggravating consumption you read about on the 'net is PCV related. Some engines hork a lot more oil mist into the PCV than others. One period of GM LT or LS engines (I forget which) in F-body Camaros and Firechickens was notorious for PCV consumption. The PT Cruiser (non-turbo) is also (been there, fixed that). People automatically assume that oil consumption is past the rings or valves, but the PCV system is another path that's often overlooked.

 

[Olas]

Originally Posted By: 440Magnum
Break-in is one cause. But I think a lot of the aggravating consumption you read about on the 'net is PCV related. Some engines hork a lot more oil mist into the PCV than others. One period of GM LT or LS engines (I forget which) in F-body Camaros and Firechickens was notorious for PCV consumption. The PT Cruiser (non-turbo) is also (been there, fixed that). People automatically assume that oil consumption is past the rings or valves, but the PCV system is another path that's often overlooked.



You're right in that it is often overlooked but then there are vehicles that dont have a pcv system..mine included..and a lot of folks who have pcv consumption issues fix the issue with VTA. I hope this doesn't sound arsey but the OP asked about new/low mileage engines and when I replied to him I assumed he meant a motor that wasn't old enough to have a stuck/gummed up valve.

 

[440Magnum]

Originally Posted By: Olas
Originally Posted By: 440Magnum
Break-in is one cause. But I think a lot of the aggravating consumption you read about on the 'net is PCV related. Some engines hork a lot more oil mist into the PCV than others. One period of GM LT or LS engines (I forget which) in F-body Camaros and Firechickens was notorious for PCV consumption. The PT Cruiser (non-turbo) is also (been there, fixed that). People automatically assume that oil consumption is past the rings or valves, but the PCV system is another path that's often overlooked.



You're right in that it is often overlooked but then there are vehicles that dont have a pcv system..mine included..and a lot of folks who have pcv consumption issues fix the issue with VTA. I hope this doesn't sound arsey but the OP asked about new/low mileage engines and when I replied to him I assumed he meant a motor that wasn't old enough to have a stuck/gummed up valve.


Doesn't even require the valve be stuck or gummed- some PCV and CCV systems don't have good enough mist/air separation where they draw the air from the crankcase and into the PCV or CCV plumbing. That's the case with the older F-bodies, many of which snorted oil through the PCV from mile zero, and its the case with a whole bunch of FWD Mopars, especially using the EDZ engine like the PT.

 

[Merkava_4]

It's because the manufacturer is specifying 0W-20/5W-20 when the engine really needs a 30 weight.

 

[jrustles]

PCV shouldn't have an abnormally high volume to begin with. That would be due to excessive positive crankcase pressure, caused by- wait for it, wait for it, excessive blow by

 

[SteveSRT8]

Originally Posted By: Merkava_4
It's because the manufacturer is specifying 0W-20/5W-20 when the engine really needs a 30 weight.



Sadly it may also reflect more on the oil's volatility spec...

 

[Flareside302]

break in.. people have been told to go easy on them...

when you need to beat the [censored] out of it..

why do you think any engine builders, build an engine, throw immediately on dyno..

I had 5 miles on my engine and full throttle till 5500rpms and now 8k miles.. no consumption.

 

[KrisZ]

All I know is that my Mazda 3 was driven normally during the break in period and was definitely not beaten up, pretty much per Mazda's recommendation in owner's manual. The FF was changed at 5k miles, per manual, as well. It's approaching 120k miles and the oil level never changes on the dipstick during the course of 5k miles or 6 months.

 

[CaspianM]

Originally Posted By: Flareside302
break in.. people have been told to go easy on them...

when you need to beat the [censored] out of it..

why do you think any engine builders, build an engine, throw immediately on dyno..

I had 5 miles on my engine and full throttle till 5500rpms and now 8k miles.. no consumption.


That you should not have done. Redlining a new engine is not the best way. Wide open throttle mid range rpm get the best expansion on the rings. As you add miles then you may gradually open op the rev. However rings get seated in less than 50 miles. Most cars get dyno-ed at the factory at last assembly point as QA anyway.

 

[demarpaint]

Originally Posted By: CaspianM
Originally Posted By: Flareside302
break in.. people have been told to go easy on them...

when you need to beat the [censored] out of it..

why do you think any engine builders, build an engine, throw immediately on dyno..

I had 5 miles on my engine and full throttle till 5500rpms and now 8k miles.. no consumption.


That you should not have done. Redlining a new engine is not the best way. Wide open throttle mid range rpm get the best expansion on the rings. As you add miles then you may gradually open op the rev. However rings get seated in less than 50 miles. Most cars get dyno-ed at the factory at last assembly point as QA anyway.


Just to clarify. In other words are you saying get up to about 2,500 rpms and then bring it up to WOT? After the engine oil has reached normal operating temps? It seems everyone has a slightly different opinion on this topic. Thanks.

 

[CaspianM]

I say 60-70%rpm but full throttle. But that is with a new car off the lot. Yes peak operating temp. I may add that is only for a brief time not extended. It should also be followed by a cool down then repeat a couple of times. Rings would be set perfectly then.

 

[demarpaint]

Originally Posted By: CaspianM
I say 60-70%. But that is with a new car off the lot. Yes peak operating temp. I may add that is only for a brief time not extended. It should also be followed by a cool down then repeat a couple of times. Rings would be set perfectly then.

Thanks!

 

[CaspianM]

I would never do this with trans in 1st or 2nd gear as there is very little resistance. HW speed possibly 3rd or higher so that to be able to achieve about 60% rpm w/ full throttle w/o downshift or crazy over speeding.