# Why do engines "use oil"?



## DoomsDave (Dec 6, 2018)

The engines in my more recent cars (well, the newest is a 2001) seem to "use oil". What, exactly does that mean? Is it burning oil at a low enough rate that you can't see it? Or maybe leaking somewhere in little bits?

Any thoughts?


----------



## Nealtw (Jun 22, 2017)

Leaks usually show on on the ground even if they only leak at speed. 

There are lots of places oil can slip thru with the age of the engine.


----------



## Colbyt (Jan 27, 2014)

Around the valves and piston rings is the most common 'burn' points.


With a 2001 or older model I would not be concerned unless the oil consumption is more than a quart every 1000 miles.


Leaks can be anywhere. Oil pan seals and valve cover gaskets being the the most common.


----------



## CodeMatters (Aug 16, 2017)

Most likely being burnt after leaking past valve seals or piston rings.


----------



## DoomsDave (Dec 6, 2018)

Just checked this morning, no problem.

The car has about 160,000 miles on it, so it's no cream puff.


----------



## MTN REMODEL LLC (Sep 11, 2010)

Anybody know the advantages of "higher mileage" car oil.

The viscosty rateing are often the very same.* What, or how does "higher mileage" oil accomplish anything.*

Is it just a cleaner, or does it slow oil consumption in older engines.

Most all the makers have a variation of "higher mileage" oil.

(I have a higher mileage 528XI, but I am still only using full synthetic. I don't have excessive oil consumption, but would there be an advantage to going with a hiher mileage oil....often identified at over 75K miles.)


----------



## SPS-1 (Oct 21, 2008)

The high mileage oils have additives that swell the rubber in seals (valve guide, front and rear crank seals, etc). If seals are worn, suppose it will reduce oil consumption.


----------



## DoomsDave (Dec 6, 2018)

Hmm. Looks like I'll be getting Higher Mileage Oil.


----------



## Windows on Wash (Aug 30, 2011)

Engines use oil because people run cheap dino oil instead of synthetics...

@ron45


----------



## DoomsDave (Dec 6, 2018)

Windows on Wash said:


> Engines use oil because people run cheap dino oil instead of synthetics...
> 
> @ron45


Might be worth considering a switch.


----------



## Oso954 (Jun 23, 2012)

> The high mileage oils have additives that swell the rubber in seals (valve guide, front and rear crank seals, etc). If seals are worn, suppose it will reduce oil consumption.


The drawback to that approach is once the seals swell and you get a little wear on them, you are hooked to using it, or another similar product. If you go back to straight Dino oil, the seals shrink back down and your leaks are worse than ever.

That is how Andy Granatelli sold a lot of STP.


----------



## Brainbucket (Mar 30, 2015)

Most vehicles that use oil usually bad valve seals or worn valve guides. If the engine has been severely overheated, then the rings will loose temper and might start using oil. An engine that's has not been maintained ie oil changes will sludge up and make the oil rings clog up and start using oil. Carburetor engines add worn rings. But there are other ways. I bought a new 2002 Camaro SS 35th Limited edition with the silver checkered stripes, LS1 5.7 and at 500 miles it had used 3 quarts of oil. I was livid. They said that's normal break in. I said bull***t. So I started to look at where is was going. I eventually pulled the throttle body and looked inside. I noticed that oil was fanning out right behind the throttle body. I looked and it was coming from the pcv valve inlet to the intake manifold. The pcv valve was sucking the oil from the valve cover. I had the slow the air flow down. I stuck piece of a crank case breather element from a 83 GMC and put it in front of the pcv valve. It stopped using oil. The engines of today spray oil and it rains oil on the inside. Not like old school where the oil drips down the lifter valley. I then learned the LS1 in the corvette has a improved pcv system that corrected the oil air flow problem but they didn't put it on the Camaro LS1. God I was pissed. So you never know.:vs_cool:


----------



## Brainbucket (Mar 30, 2015)

Oso954 said:


> The drawback to that approach is once the seals swell and you get a little wear on them, you are hooked to using it, or another similar product. If you go back to straight Dino oil, the seals shrink back down and your leaks are worse than ever.
> 
> That is how Andy Granatelli sold a lot of STP.



Old use car lots use to add brake fluid in the oil and anything rubber would swell up and seal the oil leak or slow it down. But after a little while, seals would wear fast and then oil leaks would pour. Then the expensive repair.

:vs_cool:


----------



## DoomsDave (Dec 6, 2018)

Thanks to everyone for your constructive commentary.

Keep it coming.

My car isn't using that much oil, though vigilance is still required. It is a 2001, 19 years old.


----------



## 3onthetree (Dec 7, 2018)

For burning (rather than leaking) do an oil consumption test over a period of time. Double check like for GM, I believe for many engines, is "ok" with burning 1qt/2K miles. Though some GM vehicles with AFM and Honda with VCM burn extra oil from cylinder deactivation (which was unintended). 

You can also check your oxygen sensor and exhaust for coating. A clogged PCV valve could lead to more oil consumption too.

You can switch to a high-mileage oil with the additives, but if you don't have any leaks and have always used a synthetic as dictated by the car brand, it probably isn't much better than the synthetic. How many miles on what type of engine and your driving style play a part in that decision too.

I stayed out of that other oil thread zinger, but engine tolerances are based on the oil that the car brand has designed it around. Always stick to those, and for cars in the last decade or more, that involves full or blended synthetics. Don't switch to conventional because its cheaper or you think because its "thicker" it won't slip past your weary rings or seals.


----------



## sestivers (Aug 10, 2007)

@Colbyt and @Brainbucket sum it up pretty well. All I would add is that burning is typically much more of an effect on oil consumption than loss by leakage. Virtually every car on the road is leaking some amount of oil somewhere. It doesn't always make it onto the ground in your driveway.


----------



## 3onthetree (Dec 7, 2018)

Brainbucket said:


> The pcv valve was sucking the oil from the valve cover. I had the slow the air flow down. I stuck piece of a crank case breather element from a 83 GMC and put it in front of the pcv valve.


A lot of DIYers put a catch can in. GM had to redesign the valve covers on a few engines with a deflector because of that.


----------



## ktownskier (Aug 22, 2018)

Why do engines use oil? 

Because no one bothered to put Martini's, Manhattan's or Old Fashion's in them. 

Although a few of them did run on moonshine...

Ba dump, bump...


----------



## u3b3rg33k (Jul 17, 2018)

DoomsDave said:


> The engines in my more recent cars (well, the newest is a 2001) seem to "use oil". What, exactly does that mean? Is it burning oil at a low enough rate that you can't see it? Or maybe leaking somewhere in little bits?
> 
> Any thoughts?


hot oil evaporates over time which is why we have the NOACK test/ASTM D5800. 

oil is left on parts (i.e. cylinder walls) on purpose and is slowly consumed (oil control/scraper ring does not remove ALL oil, nor should it).

blowby/PCV moves atomized oil out of the crank case (the separators aren't perfect) into the intake.

turbos love to consume oil due to the styles of shaft "seals" used (i view it more like the oil is given the opportunity to return to the oil pan, most of it choses to do so).

lastly, worn parts leak oil where they shouldn't (to the outside of the engine, valve stem seals leak into the intake/exhaust systems, etc).


----------



## SeniorSitizen (Sep 10, 2012)

Uses oil because you put* Motor* oil in it. Find a bottle of oil that reads *Engine* oil and try that.:vs_laugh::vs_laugh::vs_laugh:


----------



## Dave Sal (Dec 20, 2012)

My car, a 2000 BMW 5 series, uses no oil between 5k mile oil changes. The following year of production, they made some modifications to the engine, which included changes to the piston rings, and those cars have earned a reputation as oil burners, with some burning a quart or more every couple thousand miles.


----------



## BigJim (Sep 2, 2008)

3onthetree said:


> A lot of DIYers put a catch can in. GM had to redesign the valve covers on a few engines with a deflector because of that.


I had a lot of blow by so I put one of the catch cans on our Sentra, it does work, at least it did on ours til the blame engine went south. You can check to see how much blow by you have by cranking the engine and take the oil fill cap off. Be ready to put the cap back on quickly, because if it has a lot of blow by you are going to spray oil everywhere.


----------



## sestivers (Aug 10, 2007)

Here are photos that will help to understand what happens when the oil problems mentioned by @*Brainbucket* occur. The piston rings are supposed to scrape extra oil off the cylinder walls during the down stroke. The oil is then supposed to go through holes on the side of the piston and then drop back down into the oil pan. If the rings or holes are clogged, the oil is instead left on the cylinder walls and is burned to escape as combustion products with the exhaust (including soot). Some of the carbonizes on the piston, exacerbating the inability for the oil to be returned to the oil pan.
First photo shows fouled piston rings and clogged holes. Second is after it was cleaned, holes drilled larger in diameter and extra hole added.


----------



## DoomsDave (Dec 6, 2018)

ktownskier said:


> Why do engines use oil?
> 
> Because no one bothered to put Martini's, Manhattan's or Old Fashion's in them.
> 
> ...


Which is why I don't use oil, neither . . . . :vs_cool: :devil3:


----------



## huesmann (Aug 18, 2011)

sestivers said:


> @Colbyt and @Brainbucket sum it up pretty well. All I would add is that burning is typically much more of an effect on oil consumption than loss by leakage. Virtually every car on the road is leaking some amount of oil somewhere. It doesn't always make it onto the ground in your driveway.


This. Cars leak oil. Look at any place on the road where there's a bump or dip. You'll see the pavement around it with an oil slick around it from the thousands of tiny drops of oil that get bumped off cars when they're jostled over the bump.


----------



## ukrkoz (Dec 31, 2010)

I have no doubt BB covered this, we are normally on the same tune.
Oil consumption is due to new and improved pistons design. I.E., lighter, shorter pistons with very short "head".
In pursuit of faster revving, better mpg/power engines, designers try to eliminate any weight and mass possible. Hence, they reduce weight and size of moving parts, piston being one of them.
Shortened piston "head" and use of light alloys leads to them overheating not just at the leading surface but, also, across the entire upper section. That, in its turn, leads to quick oil burn out, caking, in very now small oil channels. That, in its turn, leads to caked piston rings, losing its function as seal and oil into crankcase drip prevention.
Next reason is same in origin. Very short piston contact surface to cylinder results in piston ever so slightly oscillating in the cylinder bore, as it does not have enough contact surface to mate snug with it and wobbles while going up and down.
Yet another reason is drive towards very high compression, what forces hot gasses into crankcase past short piston head.
Last, but not least, is lack of proper engine break in. Engines are baby-d, thus, rings are not properly set into the cylinder bore and start leaking soon enough. 

Cheers. Buy old heavy engines with huge heavy pistons. No race horses but ain't got that problem. This is why diesels are slanted to death. too reliable as, partially, if you look at pistons - they are about twice as large and everything is beefed up as possible. No good. They need to SELL new cars, not make them run forever.


----------



## ron45 (Feb 25, 2014)

Windows on Wash said:


> Engines use oil because people run cheap dino oil instead of synthetics...
> 
> @ron45


----------



## DoomsDave (Dec 6, 2018)

I've had the vehicles checked and the mechanic says they're not burning oil. I think @ukrkoz's point is on target; it's the newer engines that have had that issue. The old boats I used to have don't do that.


----------



## ukrkoz (Dec 31, 2010)

Yep. My 98 MGM (188 000 miles) eats miles and drinks* NO *oil. Not even sure why I do 5000 miles oil changes. But my 2019 RAM with 6000 miles on it already has soot in tailpipe.


----------



## pbr333 (May 8, 2019)

DoomDave there are a lot of posts in this thread but only one was
100% correct! (facts and nothing but the facts)

His post was not the long drawn out explanation filled with cliches or old wise man tales, his post was neat ,clean and to the point. 

So IMHO the only correct answer you should consider here is from ..(drum roll)

....u3b3rg33k Congradulations ! 
Reading it was like reading from a technical manual but better. He also added just enough real world view words to bring attention to the important details .
Smart man,we need to pay attention to his posts.
My posts do not reflect the opinions of this forum or its staff and should only be considered as my own opinion.! 
sp1q :vs_cool:


----------



## pbr333 (May 8, 2019)

Yes they use oil...if they did not...they wouldn't run very long.

Hey let's all put catch-cans on our cars and never have to have carbon cleaning done ever again! If you drive a BMW or any other performance oriented ,late model vehicle the catch-can will save you the price of a BG clean which is 
what? $160 ?? 

sp1q


----------



## ron45 (Feb 25, 2014)

Do your homework.


----------



## Windows on Wash (Aug 30, 2011)

An well functioning engine should not use oil. Manufacturers, forever, have used the 1 quart per 1,000 miles to CYA. 

No reason it should use that. Oil control and compression rings are stuck in most cases. 

Part of the reason that BG109 works so well.


----------



## huesmann (Aug 18, 2011)

Man that Scotty guy really slobbers when he talks!


----------



## SeniorSitizen (Sep 10, 2012)

huesmann said:


> Man that Scotty guy really slobbers when he talks!


His brain has been fried.


----------



## huesmann (Aug 18, 2011)

Are we sure Geddy Lee isn't moonlighting as a mechanic?


----------



## Oso954 (Jun 23, 2012)

Older vehicles used, burned, leaked, far more oil than today’s vehicles. They used to keep 1qt jars of oil (later cans) of oil on the pump islands. 

The attendant would just check under the hood as a standard service. When the hood releases started moving inside the car, it became more customary to ask shall I check the oil for you. They knew that every 2nd or 3rd car would need oil.

There were some customers with older cars that would jokingly say, fill it up with oil and check the gas. They were not far off in many cases.


----------



## Bigplanz (Apr 10, 2009)

SeniorSitizen said:


> His brain has been fried.


He sounds like he is hammered in every video. It is like listening to that one guy at the end of the bar that everyone is trying not to hear. Sort of feel sorry for him, like, what happened? I am sure he was on point at one time in his career.


----------



## fireguy (May 3, 2007)

Oso954 said:


> Older vehicles used, burned, leaked, far more oil than today’s vehicles. They used to keep 1qt jars of oil (later cans) of oil on the pump islands.
> 
> The attendant would just check under the hood as a standard service. When the hood releases started moving inside the car, it became more customary to ask shall I check the oil for you. They knew that every 2nd or 3rd car would need oil.
> 
> There were some customers with older cars that would jokingly say, fill it up with oil and check the gas. They were not far off in many cases.


I had a Chevy pick-up with the 292 6 cyl. Cost was $325.00, $50.00 month for 7 months. When coasting down hill, if it was not smoking, I would pull over at the next wide spot and add oil. When I was at the fire house, I got the used engine oil, cheaper. I even put in used 90Wt if it was avalible.


----------



## CPAMAN (Dec 10, 2011)

Maybe try using a higher viscosity oil. 

Some new cars tend to burn oil but it stops after a few thousand miles.


----------



## Windows on Wash (Aug 30, 2011)

Run BG 109 through the engine at the next oil change. 



Get the car to operating temp, put in 1 can of BG109 per 4 quarts of oil. Let the car idle for about 30 minutes with the 109 in it. Empty the oil. Put in new oil and filter.


----------



## ron45 (Feb 25, 2014)

Never had an older car use oil just the new ones starting around 2003.

Ole Scotty still gets his point across but he needs to stop waving his hands around too much.


----------



## Skin123 (Jan 4, 2020)

I don’t know if I’ve done the right thing or not. I’m looking for such a tool. Help. Thanks.


----------



## Skin123 (Jan 4, 2020)

To smell fresh leather in the cabin. Maybe someone knows which perfume is suitable for this?
Has anyone tried such a tool? https://leather-toolkits.com/reviews/best-leather-scents-for-cars/


----------



## Dave Sal (Dec 20, 2012)

ron45 said:


> Ole Scotty still gets his point across but he needs to stop waving his hands around too much.



There was a local car dealer named Al Piemonte who ran a Ford dealership in the 90's and had many commercials. He reminded me of Scotty. The guy could not keep his hands still if his life depended on it. Behold.


----------



## papereater (Sep 16, 2016)

CPAMAN said:


> Maybe try using a higher viscosity oil.
> 
> Some new cars tend to burn oil but it stops after a few thousand miles.


I know some car enthusiasts do that- Alfa Romeo owners are known for using 20w-50 for their S3 Spiders, but the manufacturer never recommends that- 10w-50 or 10w-40. 

Just beware that higher viscosity may mean thicker oil , and equated with less oil burning/useage, but one thing will be for certain- thicker oil means slower oil FLOW, especially critical upon cold start up, when most engine wear occurs. This can translate to earlier engine wear.


----------



## Windows on Wash (Aug 30, 2011)

If the engine is using the indicated viscosity range oil at an above spec rate, putting in thicker oil may buy you a bit of time, but it isn't fixing the issue. Based on the tolerances and indicating ranges of these newer motors, it may accelerate the failure of the ICE as well. 

That trick did work back in the day, but these newer motors are new type of animals.


----------



## u3b3rg33k (Jul 17, 2018)

it sounds like a bit of an urban myth to me. how is going from a hot cSt of 9.6 to a hot cSt of 13 going to drastically reduce leaks?


----------



## Bigplanz (Apr 10, 2009)

Note: using oil of the wrong weight can void your warranty. With variable valve timing systems, etc. the system is calibrated to a very specific weight oil. Use of a heavier oil can cause problems.


----------



## ron45 (Feb 25, 2014)

Some will remember
Some have bad things to say
Some have good things to say
Some even went as far as having lawsuits


----------



## ron45 (Feb 25, 2014)

Do you believe.

Or did it kill your engine.


----------



## ron45 (Feb 25, 2014)

....................?


----------



## ron45 (Feb 25, 2014)

Volkswagen Beetle...

Not water cooled but air cooled.

No synthetic oil just regular oil.

Why didn't those engines blow.????


----------



## u3b3rg33k (Jul 17, 2018)

Bigplanz said:


> Note: using oil of the wrong weight can void your warranty. With variable valve timing systems, etc. the system is calibrated to a very specific weight oil. Use of a heavier oil can cause problems.


I wouldn't run 10w60 in an engine that asked for 0w20, but most of those VVT systems have to cope with cold oil sometimes.


----------



## Oso954 (Jun 23, 2012)

> Why didn't those engines blow.????


They did. I’ve pulled dozens of them out for spun bearings, burnt valves, and more catastrophic failures.
VWs were sensitive to oil fill and required regular oil changes. Slack off on those, and the engine cooked, particularly in 100+ degree temps.

Anything that reduced oil flow thru the oil cooler would contribute to the engine overheating. Overheat it too much or too often, it failed.

A lot of college students and young hippies didn’t realize the difference between their older VWs and american engines, resulting in problems.

It was fortunate that parts were cheap and so were used engines from the junkyard.

Some mechanics used to set the valves a couple thousandths wider on the cylinder nearest the oil cooler, to avoid burning the valves in that cylinder.


----------



## ron45 (Feb 25, 2014)

Oso954 said:


> They did. I’ve pulled dozens of them out for spun bearings, burnt valves, and more catastrophic failures.
> VWs were sensitive to oil fill and required regular oil changes. Slack off on those, and the engine cooked, particularly in 100+ degree temps.
> 
> Anything that reduced oil flow thru the oil cooler would contribute to the engine overheating. Overheat it too much or too often, it failed.
> ...


I had several Beetles and so did my friends, we didn't have any problems other then the normal such as points etc..

Now it would be stupid to say no Volkswagen engines ever blew. 
But none ever blew because of the type of oil.
They didn't use oil unless they were abused.

The most common trouble with the beetles was heat in the winter and rusty floorboards.


----------

