FBJason

So just earlier today I was driving I was in 3rd gear at about 5k rpm and all of a sudden a ton of smoke billowed out of the exhaust for about 5 seconds then it was gone. I pulled over just to take a look and noticed when I pulled the dipstick out that the oil level was about halfway up the entire dipstick. The oil was changed not even 1000 miles ago and I just topped it off yesterday. It cranked back up immediately and idled fine. I let it sit to see if it would over heat or die but after about 15 minutes it was perfect as usual so I drove it 8 miles home. During the ride home it was normal, no smoke, didnt over heat, still drove nice and smooth. I didnt rev it over 4k though. Got home and started to look some more and noticed that what I think is a pcv valve that is t'd into the line off the oil fill neck and into the carb had spit some oil out onto the motor as you'll see in the first pic and in the second pic part of the carb which is pointed to with a screwdriver had oil sitting in it. What do you think might of happened? Im still learning about rotaries so I dont have a clue. Thanks for your help?

also forgot to say its a 83 12a with sterling nikki carb. No other engine mods except rb exhaust and hollley fuel pump and fpr.

DivinDriver

iTrader: (15)

You've got an issue with your crankcase ventilation, and had rotor blowby pressure push oil into your vent system, and then into your intake.

The area you're pointing to with the screwdriver is the bowl vent exit. it would collect oil only if oil is pushing up the vent line into the carb.

The vacuum plumbing in the first picture is non-stock; without seeing more about how it's hooked up, I can't really guess what is going on, but it looks like that valve was rebuilt with epoxy at some point, and the vent system modified.

Is it possible you over filled your oil? Too much oil in the crankcase can cause the vent system to back up, as well as having other unpleasant effects

j9fd3s

iTrader: (3)

yes, yes i would suspect this as well

FBJason

There is a chance that I did overfill it because I didnt check to see how much oil was in it when I topped it off. I just knew that usually after a few days it needs it and I was in a hurry so I poured some in.

What other things should I pay attention to on or around the motor to see if it may be a more serious problem? This is my first rotary so i dont know what adverse characteristics really are for it. Also if it was the coolant o ring would the car overheat? Thats what came to mind at first when it happened

DivinDriver

iTrader: (15)

A leaky coolant o-ring can cause an overheat, depending on where in the rotor housing it's leaking. It can also cause overpressure in the coolant system (will push out antifreeze or create leaks) or can result in the smell of burning antifreeze coming from your exhaust - sweet-smelling steam, rather than smoke. In all cases you'll lose coolant, which eventually shows up as an overheat as well.

Shouldn't mess with your oil, though, unless it's leaking into the crankcase. in which case you'd usually see frothy oil or antifreeze on the dipstick.

FBJason

ok so thats not too different from a blown head gasket. I consider myself a very competent mechanic. Have built several different cars, just new to rotarys.

Im leaning towards your idea of just overfilled oil since the car still cranks up and idles perfectly and the little bit of smoke it produces now is definitely burnt oil and it is somewhat high on the dipstick

Colbskee

i had this problem. drain your oil, refill to correct level and enjoy no smoke.

Colbskee

That's the RX7Carl rats nest removal from what the pics look like.

ray green

iTrader: (14)

Something similar happened to me once in my 84 GSL. The engine ran fine, about 150,000 miles on it and no more than a small amount of smoke for a few seconds after starting it cold.

Then one day I was sitting in the right lane at a stop light and needed to get ahead of the rest of the traffic to get into the left lane for a left hand turn. So when the light turned I took off a lot faster than I usually do and revved it up to 5-6000 rpm in the low gears.

Just as I managed to pull in front of the guy on my left, who must have thought I wanted to drag race because he wasn't being very cooperative, a massive cloud of bluish smoke emerged from the back of the car. No other symptoms, no power loss no unusual noise, but I couldn't see the guy behind me anymore as I took my left hand turn.

Like you, I figured that smoke was some kind of disaster and prepared for the worst, I thought I'd need an engine rebuild for sure. But the smoke immediately started to clear and by the time I got a few hundred feet down the road everything was normal and it never happened again. That 12A continued to run strong for another 30,000 miles before losing an apex seal.

So like the guys above said, it sounds like a little oil blew by when you raced it, maybe made worse by an overfull crankcase. It was a good reminder for me not to beat on the car, hopefully you'll get lucky like I did and never see that problem again.