jacobcartmill

iTrader: (6)

hey guys, first of all i should say that its about time for an oil change in the rx7 (its been about 2500 miles) and i use 20w50 castrol and mobil1 oil filters.

so i've noticed a couple times now that if i redline second gear and just get off of the throttle, letting the rpms drop while still in gear, i get some smoke out of the exhaust.

this happened once and i got a bad feeling. so a few hours later when i was driving around i decided i'd see if i could make it smoke again. so i redlined second gear, let off the gas and let the RPMs drop while still in gear and no smoke... so i did it again and no smoke... so one more time for ***** and giggles, and it did it. i noticed a little smoke during decel around 4500-5000 rpms. it wasnt a huge cloud of smoke, but enough to see at night with the brake lights on...
i was thinking that this could possibly just be something that happens when the oil needs to be change. it will only happen after reaming on the car 2-3 times straight, and i was thinking maybe its just because the oil is getting thin from not being changed in 2500 miles..

my question is, should i be worried?

jacobcartmill

iTrader: (6)

come on people. 16 views and no replies?

a couple people thing its a little bit of blowby getting through the turbo oil seals. the turbo has seen 15psi a couple of times when i was running race gas so i was thinking that maybe the TURBO is the source of this oil loss problem... what do you all think?

xfeastonarsex

iTrader: (5)

Many views and few replies seems to be the going tend around here. I am not sure if it is a bad thing or not, I do know of a guy that I used to autocross with whose car would smoke on decel, I dont remember it doing it before the last couple of races.
Could it be the OMP pumping oil(not 100% sure on he it exactly works, electronics wise) in and it just getting burned off?

oakback

Almost every time I redline and let off, I get a cloud behind me. It's oil smoke, from bad oil seals. Sure I'm burning oil, so I just add more. It doesn't smoke any other time, so I don't worry about it.

Of course, mine is n/a, so I don't know if that'll help you.

Turbonut

iTrader: (1)

I say no problem, as long as it doesn't look as though someone is sending a smoke signal. The throttle plates are closed on decelleration, creating high vacuum within the engine, therefore sucking oil into the chamber. You'll find the same reaction on a piston engine. It will suck oil past the rings into the combustion chamber. After a hard run to top end of any gear, don't use the engine as a "brake". Shift into the appropriate gear, or push the clutch in.

jacobcartmill

iTrader: (6)

well that is good news

fstrnyou

haha, old thread tho, but mine smokes lots when i let off the gas after boosting. when i boost 10+ and let off the gas, it takes about a sec or two before it looks like the smoke from a pile of burning leaves. yeah, it's oil, but i'm not sure if it's from constantly running 15-22psi on the stock turbo, or engine oil seals leaking.

bcool

Hella old bump but i'm experiencing similar problems on my 20B, i smoked everyone out of the dyno room today. I'm just curious if some sort of PCV system would cure this ailment. Its not really an issue on the street but when i let off today on the dyno at 8K i got a massive smoke screen. Its just kind of embarassing when everybody has to leave the room.

stevensimon

iTrader: (11)

can you send me pics of your 20b? i didnt know anyone in idaho had one.

spot_skater

Happens to me, too. Massive smoke screen and backfires when decelling from red-line. I think it's just the computer dumping fuel and oil into the motor after 5k, to keep from blowing the motor. Doesn't happen on every day driving, but if I redline a gear and shift, sometimes there will be a puff of smoke and a backfire.

Mods in sig.

James

Wankel7

The ECU is not controling the oil going into your engine. The smoke could be oil burning away on its own or the fuel incjectors or staying on a lil longer than they should. When you let off the gas.

Checked your TPS lately?

James

bcool

I'm running standalone and i dont run any sort of OMP, even if i was there would be no way for it to force that much oil into the motor. All fuel is cut on decel above about 1500 anyways so that has nothing to do with it. The only place that this oil could be coming from is past the oil control rings. I'm guessing this has something to do with the way the crankcase is vented. Currently its just running open to the atmosphere. This is the way my old n/a was and it would happen on high rev decel as well.

fstrnyou

well dang, i was really hoping it was my turbo causing the smoke and not the control rings. hmmm....

mine is worse now tho. it won't necessarily do it when it's cold, but i know that when it's warmed up it'll smoke between shifts even if i'm only revving it to 3k. not even flooring it, just normal driving. and just a few weeks ago it started smoking continuously. it's a light smoke but it builds up when i'm stopped at a light. there was a guy behind me the other day and he actually backed up. again, it's not a heavy cloud but you can see it.