Oil consumption or idiocy?

I don’t have much experience working on old engines.  How fast can an engine burn oil?  All of it in 100miles?

The story:

I bought a project car with a questionable history just for fun and to learn more about working on cars.  I changed the oil right away.  Maybe 200 miles later I took it to an independent shop for some AC work I was unable to do myself.  They said they couldn’t even see oil on the dipstick.  I figure between me being a idiot and them exaggerating it probably was a little low on oil.  So I let them change/fill it just to get it done right away.  66 miles later I checked the oil and there was nothing on the dipstick.  WTF!  Could it have used that much oil?  Or did the shop forget to fill it up?  It’s not a car I need to drive so I haven’t spoken to them about it.  Yet.

Do you think something is up with the car?  There has always been a lot of soot on the back of the car but it passed emissions testing.  Is the soot likely oil or just burning rich?  Or is the soot unrelated and all parties involved need to have their tools confiscated before they destroy this vehicle?

Thanks,

Justin

When I'm at work, and someone asks me a question about a patient, I always ask them to start off with the signalment.

In veterinary medicine, that means species, breed, age, and gender plus neutered or intact.

In the context of your question, could you provide a little more information about the car, which engine, the mileage, etc?

If it's burning you should be 'rolling coal'. Are you marking your territory? Is your PCV system working properly? Places to start.

That much oil loss would be pretty impossible to not notice. Either it is peeing out, you're creating a new hole in the ozone, or your dipstick isn't long enough (yes that is a real possibility).

I would fill it until it is full on the dipstick.  Make sure you do it when cold & on a level surface.  Then check it often to determine if it's consuming oil.  Yes some engine do use oil even from the factory but we are talking a quart over 1,000-3,000 miles.  If your's is using that much oil it will be smoking out the tail pipe or it's ending up on the ground.  When you check your oil keep in mind that if the car was just running there will be oil up in the engine still so it won't read as much on the dipstick.  If you let it set for about 15 minutes the oil will drain back into the pan so your reading should be right where you filled it to.  I assume it's a modern car so the computer should flag a problem if you start to get excessive soot build up in the exhaust system.

Integra b18c with 90000 miles.  Previous owner may have changed the oil once or twice.

In reply to purplepeopleeater :

It is not rolling coal:) Exhaust gas is not visible.  Can the PCV system cause that much oil loss?

dipstick too short?  Really?  It’s OEM I think.  I used it to check height when I filled it up.  I know I filled it to the correct level on the stick, just can’t recall with 100% certainty that I topped it up after starting it.

In reply to Ozzy :

So according to your post, if no oil on the ground and and the exhaust is not super smokey, then the shop didn’t fill it up.  I’ve only driven it 66 miles since they worked on it.  Should I fill it and check it, or should I confront the shop while it’s still empty?

That much oil burning would be insane, like....Batmobile Smoke Screen Activated insane. If you dont notice it, it isnt burning.

Leaking is way way more likely. Check the simple places first like the filter and drain plug. Plus side is the underside of your car is now rustproof for awhile

In reply to Antihero :

No puddle under the car.  It has been parked for two months in th same spot since the shop “changed” the oil.

In reply to Jah29 :

I didn't say the shop didn't fill it up.  Possibly they could have not added the right amount.  Or they filled it to the fill on the dipstick & forgot to top it after the initial start up.  If the oil filter was dry when installed it will fill with 1/2-1qt of oil.  When I do a change on any of my vehicles I pre-fill the filter before I install it.  Then I fill the engine with the remainder of the factory required amount of oil.  If it's a 5qt system that's the amount I put in.  Before I start it I verify there is oil on the dipstick.  I start and run the car for a few minutes then shut it down.  After about 10 minutes I pull the dipstick & double check it again.  It's always spot on.  If you or the shop didn't add the correct amount of oil, or didn't prefill the filter, it may not show anything on the dipstick depending on how much "stick" is bellow the hass marks on the dipstick.  If you went 66 miles without the dash lighting up like a Christmas tree or the engine locking you had plenty of oil to allow the engine to run safely.  The engines will run on very little oil just as long as the oil pump doesn't suck air & starve the engine oiling system.  They can do this for a short period of time but it's not a good idea to do it for thousands of miles.  I would just fill it to the full line (engine cold & car level).  From there I would check it every day before you start it.  If it doesn't change then switch to checking once a week.  Once your sure you are still good then I would check at least once a month unless you drive it a lot.  Also make sure the car doesn't have a higher capacity oil pan or a big filter kit on it.  If it does the system will require more oil than the factory spec.

Accurately measure the exact amount of oil and pour that much in.  Wait overnight.  Do not start it.

Next morning, check oil.  It should read halfway between full and low.  If it doesn't, you probably have the wrong dipstick.  It happened to me...

In reply to Jah29 :

Clogged pcv will pressurize the crankcase & create an unholy mess usually. Has tto be burning or leaking. Park it over a cleans piece of cardboard & see what's there next AM. If you're burning it a compression or a leakdown test will give you a clue.

I've had two high revving hondas both H22 preludes. They both drank oil. Both had loads of black soot on the rear, and the one I checked had lower than normal compression.     I ran the piss out of it. 7k rpm multiple times everytime I drove it. It drank about 1 quart every 1k miles.

 quart in 60 miles should be constant smoke out the exhaust. 

Thanks everyone.  Since I don’t have any symptoms of severe oil consumption or any oil leaks, I am going to go with the idea that it just wan’t filled enough either of the last two oil changes.  I am going to test this theory by adding oil until the dipstick shows the proper level.  And check ever 50 miles. I am not going to harass the shop, because the oil level probably wasn’t catastrophically low.

thanks,

justin

To answer the question posed by the title...

Yes.

Come to think of it, you sure theres not a lot of sludge preventing the head from draining back to the pan in a timely fashion? Depending how long you're waiting after shutdown when you check you oil, it could just be pooling onto of the head. 

Stefan said:

To answer the question posed by the title...

Yes.

That’s how my wife answers every time I ask a question with an “or” in it:)

I once owned a 66 Delta 88 that I had gotten running after a few years parked.  It burned a quart of oil every 50 miles, because the drainback holes on the cylinder heads were plugged with chunks of valve seals, I figured out during the rebuild.

It would stop traffic on a four lane highway if I matted the gas after half an hour of cruising at highway speeds.  It was berkeleying hilarious.

TGMF said:

I've had two high revving hondas both H22 preludes. They both drank oil. Both had loads of black soot on the rear, and the one I checked had lower than normal compression.     I ran the piss out of it. 7k rpm multiple times everytime I drove it. It drank about 1 quart every 1k miles.

 quart in 60 miles should be constant smoke out the exhaust. 

I've long given up on having a high revving honda that doesn't burn oil in VTEC or smoke in high RPMs.

But even 60 miles is even excessive for me if it is burning it that bad. 

Sounds like you have a plan. Have you checked coolant? I know they usually cross and you end up with coolant in the oil but just to check the box. With the questionable history you stated, probably wouldn't hurt to run some motor oil flush through it before adding oil. Get rid of some sludge.

Once bought a car cheap that burned oil to the tune of 3-4 qts every few days, about 60 miles. Bought oil by the case and kept it in the back seat floorboards. I checked/added oil every couple days and changed the filter monthly. It eventually stopped burning/leaking oil, I went to regular oil changes then. That car was badly abused by the guy I bought it off of but I needed cheap transportation in a hurry. Paid $200 for it, a 74 Pinto in 1981. Spent a total of $500 on that car including purchase price, drove it a year and put about +30k miles on it and sold it for $800. The only car I sold for more than I had into it. Was reliable transportation when I sold it.

I always put the recommended amount of oil in the engine, start it, look underneath for anything stupid leaking, shut it off, wait 15 minutes to a half hour, then check the dipstick. Wherever the oil level is at that point, I consider "full", and use that reference point for further reference. 

I run two different Hondas on track, both with K motors. Both have been known to consume the better part of a quart during a four session day which is in the ballpark of your mileage with no noticeable exhaust smoke. We're running above vtec almost the whole session though. 

So you could maybe lose a quart over 66 miles if you were wailing on it and into vtec for the entire 66 miles, in which case I salute you. However, I've never seen a Honda that didn't read oil on the dipstick until it was over two quarts low. 

i had a plymouth voyager that burned about one quart of oil for every tank of gas, and that smoked like a diesel. black soot all over the tailgate...

if you burned all your oil (or at least enough to not read on the dipstick) in 66 miles, you'd definitely see a hell of a lot of smoke

In reply to mazdeuce - Seth :

Added 1.25 quarts to get to center of the dipstick markings.  Before that nothing on the dipstick.  So less than your two quarts?  Haven’t driven or started it.

Fill it to the top mark. Take it for a 20 mile drive. You will know the answer.