So I think I've finally fixed the coolant leaks, car seems to be running good, etc etc.
But I don't remember it blowing this much oil smoke under full throttle and when you close the throttle between shifts, etc. I replaced the PCV while it was sitting. And I checked the oil and it's RIGHT at FULL. Maybe that is contributing?
I was told last year on a drive my car was puffing noticeable smoke going into corners, so presumably closed throttle.
It runs strong and is holding REALLY good oil pressure according to the gauge ('90 model) with fresh Castrol 10w-30......it is showing north of 60 psi over 5k rpms.
Lighter weight oil? Somewhere else in the system that could be causing pressure buildup?
I'm waiting for tomorrow once the engine cools down to pull and inspect plugs before I put in new ones.
Can you tell already if it is burning oil or might it just been burning off crap that might have accumulated while you were tracking all the issues you've had so far?
The only Miata I owned that puffed out visible smoke had a bad turbo...
I've put about 150 miles on it over the last 2 weeks, so I don't think it's that?
Stuck oil control ring(s) or valve seals.
Ranger50 wrote:
Stuck oil control ring(s) or valve seals.
I was starting to think the first being that the car basically wasn't driven but a few miles from November until 10 days ago.
Suggestions on ways to loosen them up? More driving?
I'm hoping it's not the valve seals since it's under heavy acceleration vs at start-up when they have had a chance to seep down?
Maybe some seafoam down the bores, let it soak for a couple of days, then do an Italian tuneup?
Valve stem seals or similar would normally show up during deceleration when the vacuum sucks oil down the valve stems. If it happens when you mash the throttle it's more likely to be stuck or worn rings.
A leakdown test might also tell you stuff you don't want to know.
I HATE HATE HATE that overpriced "foam"-E36 M3 in a can. I prefer the old standby's like kerosene and ATF in the oil.
I'm also hoping maybe my car just doesn't like being at the absolute completely full mark?
Ranger50 wrote:
I HATE HATE HATE that overpriced "foam"-E36 M3 in a can. I prefer the old standby's like kerosene and ATF in the oil.
Different thing, this isn't to flush the engine it's to blast carbon out of the cylinders. The grassroots substitute is to use carb cleaner or plain water in place of the seafoam stuff, or squirt some ATF in the cylinders and let it sit (or ideally ATF cylinder treatment followed by seafoam substitute). You should do an oil change afterwards in any case.
Soaking the engine in diesel fuel has always worked for me. Drain the oil, fill the engine with diesel- and I mean fill it, like 3-4 gallons, throw some down each cylinder, etc. Let soak for a few weeks. Drain, rinse, new oil, filter, etc.
^Not really an option, first HPDE is next weekend.
Since the car seems to be running good and all, the main reason I care is all the people that will be around me at the track. I'll throw the fresh plugs in after work, give it ye olde Italian tune-up, then maybe squirt a bit of ATF down the plug holes once it cools down.
I'm still thinking it may be a bit overfilled even though it's not showing on the dipstick. I don't remember it throwing smoke like this when I first drove it ~10 days ago. Can't imagine why the control ring(s) would stick that fast after being driven.
If you overfilled the engine, it will show on the dipstick. I managed to occasionally overfill my Miata(s) and never managed to lay a battlecruiser style smokescreen, though.
I'd actually stick the ATF or other magic potion of choice down the plug holes before the Italian tuneup and let it sit a couple of days.
If the engine has the old sludgeroo, it may be blocking the oil drainback holes to the crankcase. That'll make it smoke like crazy.
^So that just takes us back to running the engine a bit with a quart of ATF subbed for a quart of oil?
Pulled the plugs, all looked good (if a little worn) except plug #3. It was BLACK with carbon and the top of the piston looked a bit oily as well.
Fresh plugs eliminated all blue smoke during acceleration..................it appears as those 1 or more valve stem seals in piston #3 are leaking.
The only time I'm getting blue smoke is after decel, then when I roll back into the throttle I get a nice puff and then it's gone again until the next decel event.
It's running good, so I'll just keep an eye on that plug and the oil level for now and drive the crap out of it.
