I'm feaking out, man!!! E shaft oil pellet stuck?

[Max777]

Being an avid Grassroots Motorsports Magazine reader, I decided to check out their second generation RX-7 buyers guide online article today:

http://grassrootsmotorsports.com/articles/lucky-7/

In it, they mentioned the e-shaft oil pellet failure, and that it supposedly once it happens, your engine is done?

The car’s real Achilles’ heel is the eccentric shaft bypass valve. This valve lubricates the oil seals and O-rings, but only after the engine heats up. If it fails, it’s not apparent until the engine starts to smoke, and by then it is too late. Most premature engine failures can be attributed to either this problem, overheating or abuse. The solution is to replace the eccentric shaft bypass valve as a matter of course every 75,000 miles or so.

Recently, my engine has been smoking oil at random times, and I'm getting a bit paranoid that I may have toasted the oil seals due to this. I'm really hoping that the failure is the turbo, but then wont it be smoking steadily at all times?

My car has 150,000 miles on it right now. The original engine died in 1997, and was replaced right around 75,000 miles, which makes my engine have roughly 75,000 miles, give or take 10,000....

When I bought this car back in September, it tested 105 and 110 compression on both rotors. (Why I bought it) so the engine seems healthy, but could this blue smoking be a sign of needing a rebuild so soon? I would hate to trash a good motor because the oil seals crapped out.

[Justen]

Oil seals (at least the rubber o-rings) usually just crap out and disintegrate after years of heat soaking i believe. That's what happened to mine. My turbo2 smoked like a chimney on startup. When I took it apart to rebuild it, the motor and housings were okay, and even the metal oil seals, but the rubber o-rings in the oil seals weren't even there anymore. I don't think the pellet was stuck in my motor because the bearings seemed fine as well. The same thing could have happened to your motor.

As far as the thermal pellet goes, I have heard of them failing before... replaced mine with a solid pellet from Atkins that allows oil to flow through at all times and won't close at all.

If your current motor was a rebuild, the thermal pellet may have been replaced with the same thing. Was it a stock-swap or rebuild?

[Justen]

I would check for oil in the intercooler after the motor is warm:
If there is oil in there, its probably the turbo.
If not, then its probably the oil seals in the motor

[rx7 FC TII]

oil in the intercooler could be from blowby if you still have the stock emissions so dont use that as a main source of determining whats wrong.

[Max777]

Well, I cant confirm this, but the PO said the motor was supposedly a mazda reman, so it's a stock swap. However, it's missing any kind of reman tag like most I've seen, so either its just rebuilt, or they didn't have tags on them/it fell off.

No oil in the intercooler, but I still run a top mount, so it's kinda hard to get oil into it. Could it be just the exhaust side seal, or do turbo seals normally fail together? Seems like it would make more sense for the turbine side seal to give out first.

[rx4ur7]

Smoke at random times? When and what were you doing specifically? If it smokes after you get on it on spool down, check the turbos. If it smokes on start up more than likely Oil Control rings or OC orings. Would be odd for a fresh rebuild to do that though since both OC rings and orings should have been replaced.

Overheat indicators or Mazda rebuild sticker on MANA motors should not fall off, generally would have to be removed by someone.

Do not think oil will not collect in IC because it is top mount, it has to go through the IC to get to the motor to burn. That is if it compressor side of turbo.
Exhaust side seals will show only in exhaust. (usually seen on decel after hard run shifting) Try at cruise mode, get on it pretty hard then get off throttle, if you see smoke suspect turbo turbine side seal.

Other cause of excessive smoke could be metering pump over injecting oil. Not that common.

Btw Pellet controls oil through the eccentric shaft, feeding bearings and cooling oil to the rotors, some oil does get to OC rings. OC rings act similar to OC rings on a recip keeping piston/rotor cooling oil and crankcase/oil pan gases from getting to combustion chamber. We have to really rely on the rubber based orings which can go through just so many heat cycles. Yet another reason to change oil frequently, dirty oil does not act as a good heat reducer.

Oil control rings also help retain oil in the cooling chamber of the rotors, when they fail the oil drains in to the bottom of the rotor chamber. When motor fires up it burns off that oil, blue smoke on start that goes away quickly. Oil as most petroleum based fluids burn with some color, blue for oil black for fuel.

[Max777]

That seems to be it about the smoke, it happens on spool down, and just a LITTLE when starting. IF the pellet does fail, will there be no oil AT ALL going to the bearings btw? Or will there just be less of it? If the pellet controls all oil flow, then that's the dumbest bit of engineering ever conceived on an engine.

As far as removing the pellet, is it worth it to do this on an engine that is still in the car? I want to shim it, but I have read horror stories about the front bearing. I also want to replace the front cover gasket, front seal, and the main pulley with a Racing Beat version, so perhaps I should do this project sometime in the future?

Edit:

I did find some stupid stuff on the engine when I took off the intake manifold, the omp lines had bits of rubber hose connecting (presumably) broken sections, the vac routing seemed to be off, the twin scroll actuator was not hooked up to the flapper door, BOV was not hooked up to a vaccum source... etc. summing up that at least SOME of the work performed was not dealership quality.