Is oil consumption always a bad thing?

[Spector]

To some degree it is also the definition oil consumption. Many people beleive that if the oil level reads between the crosshairs it has not used any oil because it has not gone down to the add oil mark. Obvioulsy it has but it is amazing how many people have the above definition of consumption when you speak with them.

Good think we are not talking about leakers here, I have a leaker that goes a quart in 1500-2000 miles but just not worth the cost to fix.

 

[demarpaint]

Although none of my fleet uses much oil IMO, growing up in the 70's taught me that using a qt/1000 miles is acceptable (although it would bother the [censored] out of me).

Frank D

 

[JetStar]

I think it is somewhat relative. If your engine is a known oil user, like a Northstar, then no. However if you find out your specific engine is not an oil user, (lets say via a fine 4M like this) then something may be wrong.

 

[JoeFromPA]

Hi all,

I think people are beating around the bush in some answers.

If you drive an automatic Honda Accord/Chevy Malibu/Toyota Corolla/Camry etc. under normal conditions you probably shouldn't experience any oil consumption. You aren't putting your cylinders under enough pressure (most likely) to cause blow-by, or running excessively hot, or any other condition likely to cause consumption in a nicely made engine.

But if you are running a F/I engine at high loads, or have a high RPM engine with a ring design allowing more oil consumption....or both....and, say, are driving down mountainsides letting the engine brake at 80% of redline or going WOT up steep inclines...

Then I see no reason why the engine wouldn't consume some oil as part of normal operation. This isn't a sealed system here: oil gets on the walls of the cylinder where combustion occurs.

Look at how many people here are reporting "no oil consumption" but then doing 3-5k oil change intervals on their engines, in a normal application.

Yet i'm talking about 1 quart every ~4k in a high RPM application as being "normal".

Why is this contradictory?

Also, people assume that modern engines are designed in such tight tolerances that it should never consume any oil as a result of being a "modern engine"....but we know that some engines are built with looser tolerances to allow for differing levels of performance and longevity.


Just saying...

Joe

 

[1sttruck]

The Cummins in the pickup (85k miles) uses noticeably less Delvac 1 5w40 than Delvac 1300 15w40w and oil use varies with load. With only commuting I might use 1/2 qt to a qt of Delvac 1 every 5k miles.

Oil use on either Taurii (40k and 140k miles) varies with load, to the point that I could tell how my daughter was driving one of them. Going up and down hills a lot seems to result in more oil use. Oil use is probably 1 to 2 qts every 5k miles.

The 4.9L I6 in my son's 92 F150 (140k miles) uses very little oil, probably less than 1/2 qt every 5k miles.

 

[FZ1]

I agree that oil use increases with load/rpms. My Honda V6 sometimes uses 6 oz per 4k. I pull a small bass boat using cruise control and if I let the AT down shift on long hills I get this slight oil use. If I switch off the cruise control prior the hills I get no oil consumption. I just let the car naturally slow a little and remain in D as I go up the hill.

 

[JoeFromPA]

Yeah, once warmed up I'm doing full throttle runs up to 5000-5500 rpms ALOT....then a few runs to redline (8000 rpms) a few times a day. Plenty of engine braking at 4000-4500 rpms.

I found that driving this way makes me much happier and the engine doesn't change it's mileage whether I drive like this or baby it.....it's 29-30mpg regardless. And of course over 35mpg on PURE highway cruising at 70mph

Joe

 

[Gary Allan]

Yes, but D1 is just shy of "magic oil". It must have the absolute best secret mojo that XOM petro engineers can bring to the table in liquid form.

 

[kingrob]

Originally Posted By: Patman
Both of my cars use about a quart every 4-5k, and as long as it stays around that level I'm ok with that. I wouldn't want it to ever get to the point where I need to add two quarts of top up oil for every OCI though.

One engine which historically burns a lot of oil but has a very long service life is the Ford 302.


When I was coming up Ford motors had a reputation for burning oil. One quart every 6 or 700 miles was par for the course. It was just accepted as the way their engines performed.

My modern day Saturn is the same way. One quart every 7 or 800 miles. It's the design of the engine, and as long as it's not leaking I can live with that.

 

[SpitfireS]

MY00 Honda S2000.
Bought it second hand (80k km) and it used oil, 1 liter every 3000km (or so)
Oil consumption decreased (by 50% +/-) when I changed the crankshaft ventilation setup, i.e. created more vacuum in the crankcase.
Currently at 155k km.
(I have to say that engine died (= developed low oil pressure at idle) at the track at 155k km due to oil starvation, caused in a high-g turn on R-compound tires)

Break-in of the FRM cylinder walls is critical, most European S2k's IMO switch too soon to syn oil and that does not help proper break-in.

"New" engine is going this week, MY05 with 25k km.
Looking forward to it using a bit less oil, also because later F20C2 engines were honed with a dummy head.
FRM cylinderwalls were unchanged.

 

[OVERKILL]

Originally Posted By: kingrob
Originally Posted By: Patman
Both of my cars use about a quart every 4-5k, and as long as it stays around that level I'm ok with that. I wouldn't want it to ever get to the point where I need to add two quarts of top up oil for every OCI though.

One engine which historically burns a lot of oil but has a very long service life is the Ford 302.


When I was coming up Ford motors had a reputation for burning oil. One quart every 6 or 700 miles was par for the course. It was just accepted as the way their engines performed.

My modern day Saturn is the same way. One quart every 7 or 800 miles. It's the design of the engine, and as long as it's not leaking I can live with that.


Ford's 302 has a maintenance issue that most people are unfamiliar with that CAUSES oil consumption:

The PCV valve SCREEN.

On EFI 302's in car applications (Mustang, Town Car, Crown Vic, Cougar, Grand Marquis, Thunderbird....etc) the PCV valve is located in the BACK of the lower intake manifold. It fits in a rubber grommet which sits on top of a mesh screen.

This screen becomes plugged up and causes two separate issues:

1. Excessive blow-by via crankcase pressure build-up
2. Oil being sucked through the PCV valve because it "puddles" on top of the screen when the flow through the screen is impeded by build-up.

This item is HEAVILY overlooked. In the Mustang community, this is one of the first things people are directed toward replacing when experiencing oil consumption from their (stock) 302HO engines.

 

[demarpaint]

I've driven Fords pretty much for the past 30+ years and recall one problem with oil usage and that was fixed by changing valve stem seals. Other than that I had no problems with them, the stem seal issue was well after 100,000 miles on a 200 I6.

Frank D

 

[rainman49]

If you've ever owned an MGB, you know that if it wasn't burning or leaking oil, there wasn't any oil in it. Of course, I've had everything else from the most common of one-quart consumption per 3,000 miles to my daughter's 1997 Camry (2.4L) with 217,000 miles that apparently doesn't burn a drop between 6K synthetic oil changes.

 

[Nickdfresh]

Originally Posted By: ViragoBry
I don't think I'd ever find 1qt / 1000 miles to be an acceptable amount of consumption on a car with less than 100K miles....


Neither would I. I do think it is normal for cars to use varying amounts of oil, and I too had the infamous Saturn oil-burner (bad ring design), and I used just over a quart at 3000 mi., it still made me skittish...

I would personally consider anything over 1QT. per 3000 miles excessive need for drastic action such as cleaning or simply using thicker oils...

 

[Gary Allan]

This used to be common consumption. No one drove that much and oils were not this good. Nothing to sweat. The anxiety over this is the moving away from checking your oil every fuel stop (as recommended in the manual). Regardless of if there's a defect or not, the engine can be 100% functional and deliver 100% utility.

Linear consumption that doesn't cause other problems (fouled plugs, pre-ignition, etc.) is just fine. Progressive consumption point to some oil fatigue issue.

 

[John K]

I had a 66 MGB that I ran in autocrosses that I don't recall any oil consumption, but then that was a long time ago... I did drive it hard. Same with a 64 MG Midget.
Other cars - 77 Volare slant 6 that I complained to the dealer. They claimed they checked the valve stem seals and they were ok, but it was obvious that they didn't open anything up. 87 Taurus 4 used about a qt. in 3000 that I considered normal. 01 PT Cruiser used 1 qt. in 1100 - 1500 miles with many different oils tried. All of these were MT. I assume something was wrong with the valve stem seals or the piston rings. I think 1 qt. per thousand miles in a new car unacceptable, but no dealer will agree.

 

[Steelhead]

most car manuf dealer shops and regional manuf service reps will NOT even talk to an owner about excessive oil consumption until it reaches a quart per 800 miles or more.
warranty replacement before that level, forget it.

been years since i heard of a manuf. doing a warranty replacement on an engine for "excessive oil consumption"

we all benefit from modern electronics precision fuel control, diamond hone CNC engine manuf.plant cyl honing, far tighter rod bearing clearances with less oil spray, low friction piston coating and finishes, quality long life intake valve seals, more reliable PCV designs and far more robust engine oils

 

[FZ1]

Just 1 more reason to use synthetic. It burns cleaner. Lol.

 

[Lazy JW]

Originally Posted By: tonycarguy
...... There's nothing acceptable or normal about a modern engine using that much oil, regardless of how things used to be in the olden days....


They don't make cars the way they used to, and that's a GOOD thing!

Put a load of 80% or more maximum power on them for 10+ hours and they'll burn some oil.... but most modern engines will indeed burn significantly less than the old types.
Joe

 

[oldmaninsc]

Originally Posted By: jdhog
Yeah a quart every 1000 miles is OTT - you might as well dump a quart in your gas tank when you fill up at that rate (not). For most factory recommended OCI wouldn't that make them dangerously low imagine if you never checked the dipstick and let it run for the whole 5k?


Exactly. Somebody at another forum I am a member of has a GMC Envoy with the I6 engine. They had a "knocking noise" and took it to the dealership. They drained the oil and there was only 1 quart left (in a 7 quart pan).
Now this person is fighting with the warranty company to get them to replace the engine. His/her reasoning is that the engine SHOULDN'T have burned that much oil in 5 - 7k miles.
They stated: "I never received a "change engine oil light" or "service engine soon". The oil pressure gauge never moved."
Can you say idiot boys and girls?
http://forums.trailvoy.com/showthread.php?t=47237
(In the first post there is a typo they state that their vehicle has 666091 miles when in fact it was 66091 miles).

Personally I check my oil at least once a month - sometimes more. None of my vehicles use more than 1/2 a quart in between oil changes (5 - 7K miles or more).

But like Gary said - those of us who were "lucky" enough to have vehicles in the pre - 80 era know what oil consumption is all about. For some of those 1 quart in 1000 miles were considered great!