Where is my oil going?
 

I noticed my car is starting to use a lot of oil. After one autox day i was low on oil. The car is not blowing black smoke and i did not see any blow by anywhere. The car runs good it smells like burning oil when i come to a stop light tho once i an a while more then usual. I dont have a cat on the car.

So i was wondering how would i check where the oil is going?

I cleaned the tail pipe tip and drove the car around for a while. The tip got black but was very dry not oily at all? The cold side of the turbo is dry, the intake tube is dry too.

a hole in the feed line maybe?

Cam seals? crank seal? CAS seal? Notice any new oil spots from overnight parking? How many miles on the motor?

If you have an intercooler, look in there, or look in the charge pipes. Mine was blowing oil out the crankcase vent. I probably drained a quart from the intake:
Attachment 205947

Check your coolant.

I wanted to say at the feed port.

Happened to me once.

The engine is not leaking at all. I replaced all the seals. There is no oil in the charge pipes or intake pipes.

So..

It is not being burned by the engine.
It is not being leaked externally by the engine.
It is not in the charge pipes or intake.

Is your oil drain plug washer good? Any oil spots on your driveway?

Not sure how common it is on Miatas as I do not have much experience with them, but I have seen one way leaks, as in oil leaking into the coolant. Either take a peak in the coolant reservoir, or drain some into a clean pan and check for oil.

double post fail thanks to shitty interwebz

So once you top off the oil, how long does it take until it reads 1 qt low?

Do you have spots in the driveway or not? Have you tried letting the motor idle and just drink a beer and look for any squirts or leaks? Did you check the coolant?

+1 on IC pipes. I know you say yours are clean, but 90% of the times thats where it goes. I've had that happen with my old greddy setup.

Yeah i checked the IC pipes they are super clean. There absolutely no oil spots in the garage. The only time i noticed that the oil is really low was after the autocross. I am pretty sure there was ton of oil in the engine before and after i got done with autox i checked the oil and it was at the Low mark. Since then i filled it up with oil all the way to the F mark and drove it for probably 300 miles and now it sits at that o or 0 mark, right at the top of it. So not too much one but i can tell there is less oil in there. So its not like i am loosing a quart of oil every 500 miles but i can tell its eating a bit. Some people told me to make a catch can but i have no idea where to hook it up.

Thanks, Taras

I am thinking i should hook up a catch can, where do i plug it in?

read m2cupcar's catch can thread. you'll find it if you search "girly catch can"

Edit: Also, what PCV valve are you running? I feel like my motor is eating oil under high vacuum. Sometimes it'll burn a qt of oil over the course of a week, other times I dont have to add any for a month or more.

kinda sounds like my situation. I am using stock PCV valve.

I was amazed the other day when I checked my oil. I have had the turbo on for about 1,000 miles. Zero on the stick. One quart brought it up to L and one more to fill it so I was down two quarts in 1000 miles. The car had never used a drop between oil changes (5000 miles) before. Motor has 70K now. I've had the car since 51K.

No sign of burning, nothing in IC pipes, coolant is good. NO leaking on the shop floor, even when running the car in the shop for 1/2 hour straight. I had put in a Advance Auto 323GTX PCV valve. It was not the same as the Miata one that they had on the shelf, but it was still aftermarket. I had also put one of those little pleated breather filters on the driver's side of the valve cover. It is very oily.

Yeah, i got one of those little filters too.

+1. Watching this thread closely. Losing oil too. Varies a bunch by how many miles also. As much as I'm losing you would absolutely see blue smoke if it were getting burned. IC pipes are clean and dry. Haven't checked the intake mani. No drips in the garage.

So where would it be going if its not being burnt? if it goes into the intake wouldn't it eventually end up out the tail pipe?

That's the mystery. I've had cars that used this much oil before and there was always obvious blue smoke or a puddle somewhere.

thats what i thought. And my car barely blows any smoke. None at all when its cold and a little bit after i drive it hard at idle. Maybe just a bit more than my catless 2008 legacy GT. And the car runs good overall too.