Losing a lot of oil- not leaking
 

Hey guys, I've been religiously roaming this forum for the past 4 months, but never created an account so this is my first post.

I bought my car already turbo'd. The guy who turbo'd it was someone who really knew what he was doing. He lives, breathes, eats and sleeps turbo miatas. The problem is, the owner after him and before me (who I bought it from) was a complete jackass who knows nothing about cars. I've been fixing everything he "improved" on the car from the guy he bought it from.

Anyways, enough of the background. I am having an issue with burning oil. I have scoured the internet as well as this forum and have found a lot of posts about it, but rarely people commenting back on what their actual problem was or if they ever fixed it.

I have burned 2.5-3 quarts of oil in 2300 miles. I get zero smoke out of the exhaust when starting up, no matter if it has been sitting for a minute or a week. I do get some black residue that spits out from time to time (only visible on the ground after exhaust). The car smells strongly of oil only when I have high vacuum (high revs, closed throttle). I have had someone stand behind the car when I am driving off and they said that (what they thought was) black smoke coming from the exhaust.

I replaced the PCV valve from the GTX but still notice the smell when decelerating/engine braking, so I'm guessing that wasn't my issue.

The motor only has 50k on it, BUT, it sat for 6 months in the previous owner's driveway without being driven.

Does anyone know where I should begin the search for the oil leak? I'm assuming rings, because it doesn't smoke on startup, but I'd love some insight into the matter from people who have a lot more experience with this than me.

Thank you!

If it's rings, you should be able to draw oil in with decel, then floor it and it'll blow a cloud of smoke.

Pics of the engine bay would help.

2.5-3 quarts of oil in 2300 miles is an awful lot. That's over a quart per 1000 - that's more like a oil drain at that point. I'd expect very visible smoke.

Are you certain there isn't an oil leak somewhere on the engine leaking externally? At > 1 quart per 1k miles, I'd expect some pretty good smoke if it's rings.

I'm not 100% sure if it's that much, but when I got the car it was very low on oil, so I bought a 5 quart container of oil and added about 2-2.5 quarts, and in the 2000ish miles I've put on the car, I've had to put the remainder of the 5 quart container into the car to keep it consistently at F on the dipstick.

I keep the car in the same spot every day in the garage and there are 0 leaks on the ground. It could be coming out under load, I guess, but I don't think this is the issue if I had to guess, but what do I know. :loser:

I don't notice any smoke, but then again maybe I just don't see it. I look every time I smell that "burning oil" smell and never see any smoke coming from the exhaust. But, when I was driving off and had someone look at the exhaust, there was black/dark smoke coming from the exhaust. I'm assuming it's running a little rich, not related to oil.

I have noticed that there has been zero oil that has been caught by my catch can that the previous owner (jackass) installed. Is this cause for concern or maybe in any way related to this? It was bone dry when I opened it up after 3000 miles.

I will post a picture of the engine bay ASAP.

Shame shame no intro post!

1) read the forum rules
2) compression test and leak down

If your rings are shot badly you'll get little smokey puffs from your dipstick hole or breather port.

Sitting for 6 months shouldn't do anything, unless something A LOT MORE than just sitting for 6 months was happening.

As Krissets said, Compression test ASAP, then leakdown. It'll tell us what's going on - it could be rings, but I'd be more inclined to look somewhere else if you aren't getting any smoke. > 1 quart per 1k miles is not great for a rotary, let alone a piston engine.

Update
 

Just did a compression test. Exactly 150 across the board.

Today I was really doing some hard pulls to see if, and when smoke occurred. I was idling at a stop light for about 30 seconds after engine braking down a big hill. Do a hard start from the stop light, go to redline, immediately get off throttle a little. Big puff of light colored smoke behind me- I could see it lingering. Get out to see if it's still smoking, and there is zero smoke. On my way home, I engine brake on the highway, completely let off the throttle, and I can definitely smell burning of oil. No other time though unless I am going to redline and take my foot off the throttle to shift.

Oh, another thing I noticed. Spark plugs are all pretty white. Cylinder 1 more so than the others.

Any ideas?

Does it happen to have a Greddy turbo, with the originally designed Oil drain routed to the opposite side of the block?

Have you checked to see if your AC bolt is on the side of the oil pump?

If you've got enough time to do what you've described, you've got enough time to download the photobucket app, take a picture, sign up, upload it, and post the picture. Please do so.

My apologies on the photos. I meant to do that but forgot.

The turbo is a begi bell T3 turbo.

https://www.miataturbo.net/attachmen...ine=1402424674 The spark plugs when I took them out.

https://www.miataturbo.net/attachmen...ine=1402424674

https://www.miataturbo.net/attachmen...ine=1402424674

https://www.miataturbo.net/attachmen...ine=1402424674

https://www.miataturbo.net/attachmen...ine=1402424674

https://www.miataturbo.net/attachmen...ine=1402424674

Standard oil drain to the oil pan?

Do you have any restriction in the oil feed? Any oil in the intercooler pipes?

Its broke.... unrepairable..... ill give you $200 for it to get it off your hands.... lol

If all your plugs look like that then you're in good shape. Your compression numbers are also very good.

I've got symptoms darn near identical to yours on the red car. I'm in the middle of replacing the valve guide seals (updates in the build thread). Will keep advised on whether that is a resolution.

Other than leaks, places for oil to escape:
1. Piston rings
2. Valve guide seals
3. If you have a turbo car, CHRA seals (which is why Curly is asking about your drain/feed line/IC pipes)

The previous (jackass) owner told me that he changed the drain line when I just asked him, because the one on it was "too small".

The fitting the previous owner (builder) used for the feed was the exact line used by flyinmiata and begi bell engineering. The restrictor is based off of the fitting tip.

Not sure about the oil in the intercooler- I will check when I get another chance.


Hornet,Sorry to hear you're having problems but nice to know someone else is experiencing similar problems. Hopefully it is simple and we both can find the solution. Please let me know if those valve seals fix your issue- I'm really starting to think that's what my issue is. Are you using the rope method or removing the head?

Thanks for your help so far guys.

I'm going with worn turbo in this case.

If your compression numbers are that good, im thinking maybe #3 on hornetballs list. I had that issue before, but it wasnt a constant loss of oil, only under hard deceleration downhill, or idling while parked up hill in traffic. after a while being parked like that, i would drive off, and there would be an intense puff of white smoke. Found out it was because of the Shitty Greddy oil drain setup. On an incline it wasnt draining well enough, and started burning out through the turbo seals.

Hmmmm… I wouldn't be surprised in any way if it was the drain line. I've literally had to fix everything the previous (jackass ;) ) owner did to the car. This would just be one more thing added to the list.

What'd you do to fix this? New drain line?

New drain line, preferably in a manner that works. It should be as straight as possible, and all downhill.

Just took a picture of the drain line.. looks fine to me, no kinks and it's all downhill. Can you tell the health of the drain line just from looking and seeing no kinks, etc?

https://www.miataturbo.net/attachmen...ine=1402435236

That's not your problem unless it's way smaller than it looks in pictures, but that looks like a -8 or -10AN drain line, and run pretty well.