We have a 99 with 200, 000 miles on it. It is parked all over the place so I don't really see any oil dripping out of it. It for sure has some leaky seals. I never see it smoke, like never. The oil consumption is absolutely crazy. The son is daily driven by my son who loves to cruise it. It is a well used car. I think the consumption is at least a quart per week, at least. We are going to keep track of it and see.
I am new to miata's and their ways, but is this normal? Engine runs great. I would say it is down on power, but my daily is a supercharged mustang, so I think everything is down on power.
Seriously, this is getting to the, "fill it wiith oil and check the gas" type situation.
Thanks
check the cas o-ring at the back of the head, it is likely leaking there.
Mine had been buring a lot of oil due to the PCV valve being mostly useless. Lets a lot out over the exhaust, which isn't pleasant. Also a '99 with more than 200k miles.
ChasH
Reader
10/6/19 9:47 a.m.
A car leaking that much oil would make a considerable mess. Older Miatas suffer from stuck oil rings, which is the likely cause of most of the car's oil consumption.
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HalfDork
10/6/19 11:25 a.m.
People always jump to the oil rings. How about we try valve stem seals first, and that’s only after getting a leakdown test. I’m in the same boat. When I pull up to a gas station in my miata I tell the attendant to fill it up and bring a quart of oil. I’m not even bothering changing the oil right now (eventually I will, don’t poop your pants people)
The correct answer is "less than a quart between changes," at least that's what the healthy Miatas in our fleet have always done.
Zero, mine has 124k and uses zero oil
MrChaos said:
check the cas o-ring at the back of the head, it is likely leaking there.
Not on an NB, that’s an NA thing.
At this level, it’s gotta be smoking. Is it smoking under decel/idle or under power? Former is in the head, latter is in the block. If it’s not smoking, then clean the engine bay and find out where it’s leaking. It’s not evaporating.
I don’t accept any oil use on mine, personally.
buzzboy
HalfDork
10/6/19 12:49 p.m.
Have you followed the car? My e36 was losing oil to a mysterious place: no drips, no bumper soot and no noticeable smoke. A friend followed me somewhere and pointed out that it smoked like a diesel under deceleration. Ah... there goes my oil.
Cheap check is the PCV valve, clean or replace it. My 99 used over a quart on the 100 mile drive home from the purchase. Only very minor leakage (left none on the ground in 1 month). No visible smoke during that first month. Used oil at a much higher rate when driven on the highway than at slower speeds (assume this was rpm related). Could not figure out what it was & then remembered a clogged PCV valve could cause these symptoms. I was out of brake cleaner so I spent $8 and bought a new PCV valve. Oil consumption essentially ceased.
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HalfDork
10/6/19 1:14 p.m.
In reply to Keith Tanner :
That’s exactly what mine does. Down shift, ride the rpm down for awhile. Give it some pedal and it’s a James Bond car.
So thats valve stem seals? Cool. I’ll still do a leakdown. Just to do it and verify compression.
In reply to Keith Tanner :
No smoke at all, zero. We are going to start tracking this more closely. I will let you know then. For sure there are some leaky seals, but no real spots. At present I have a very leaky fox body sharing the same spaces, Some of it might be from the mustang. I park the mustang in the same spot when I drive it to the office and know that sucker is leaking.
In reply to buzzboy :
Yes, and have not seen smoke.
In reply to secretariata :
I'll have my son check the PCV valve.
We just took a spin. There is some smoke on hard acceleration and the PCV valve is clean. The smoke isn't that much. We have driven behind the car but he has never been hard on it in front of us. There are some nice oil spots where it lives. Still, the smoke and the spots are not what I would have expected with this much oil consumption.
As always, thanks for your input
ChasH
Reader
10/6/19 4:14 p.m.
In reply to Keith Tanner :
There's plenty of cases of NBs using oil just as NAs do. An engine leaking leaking a quart every coupla hundred miles will make a huge mess. Valve stem seals rarely allow so much oil bye, and if they do there will be a large cloud of oil smoke on a cold start.
In reply to ChasH :
I just realized we used to call my brother, "Chas" and his last name starts with "H".
This is a miata that I bought for me and my son totally stole it out from under me. I don't see it on cold starts and don't get to drive it as much. He is 17 and I foolishly didn't see this coming. Hopefully by the end of the week, I will have my own miata.
I should have had a father like me....
ChasH
Reader
10/6/19 7:55 p.m.
It's a small world-but I'd hate to mow it.
Good luck with your Miata.
ChasH said:
In reply to Keith Tanner :
There's plenty of cases of NBs using oil just as NAs do. An engine leaking leaking a quart every coupla hundred miles will make a huge mess. Valve stem seals rarely allow so much oil bye, and if they do there will be a large cloud of oil smoke on a cold start.
I’m not saying you can’t make them leak or use oil. I’m saying that they won’t leak out of the CAS o-ring...because they don’t have one.
thedoc said:
In reply to buzzboy :
Yes, and have not seen smoke.
I had a 72 Vega that would lose a qt in 125 miles and it didn’t smoke.
The ??? Mile BP in my escort wagon doesn’t usually smoke noticeably, but does burn oil at a rate of approximately 1 qt / 1000 miles. To be fair there's generally 1-2 autocrosses thrown in per 1000 miles. PCV valve is brand new, OEM.
The only time it did smoke horribly for me was while/after descending the Mt. Washington auto road in 1st/2nd gear. “James Bond Car” is a fun way of putting it. However, after a few minutes at highway speed it was back to normal with no more smoke in the rear view.
No smoke at all on cold starts, so I’m thinking it has to be worn oil control rings. I’d guess the OP is experiencing the same problem. Have you tried coasting down a mountain in low gear? :)
RedGT
Dork
10/7/19 10:46 a.m.
Whether the PCV valve looks clean or not doesn't really answer whether it's stuck, or opening too easily, or whatever. For the $2 or whatever it costs, replace it. When I had a failed one, it went through a lot of oil but not enough smoke to be easily visible.
Nugi
Reader
10/7/19 10:54 a.m.
This reminds me of all the discussions I see on honda and vw forums about leaks and oil consumption. Some percentage will swear that leaks and oil burning are 'a trait of the engine', when it is almost always a trait of the owners care in maint. Yes, replacing broken and leaking things is regular maint, not just adding more fluids when low. If you let it get past a quart per change, the neglect is all yours.
It is usually valvestem seals, pcv, rings, in that order.
I currently have 7 cars, 3 with over 300k, 3 with over 200k, and a 45k creampuff. None leak oil. If you wouldn't dump your used oil on the ground after every change, why would you do the same over time? Stop polluting and fix your E36 M3. /rant
When I had a new VW in 2000, 1L per 1000 km was considered acceptable according to VW. On a new car. Mine didn't use any.
If you're smoking after a long engine braking descent, I'd be looking at the top end and not the rings.
Keith Tanner said:
When I had a new VW in 2000, 1L per 1000 km was considered acceptable according to VW. On a new car. Mine didn't use any.
If you're smoking after a long engine braking descent, I'd be looking at the top end and not the rings.
That’s unfortunate as I have a line on a refreshed NB2 shortblock that I was considering tossing in there & reusing my head. Perhaps not the best plan after all…
Unbelieveable the oil consumption rate that VW considers normal? I've heard of similar issues with Subaru.
