yes I searched

1986 stock na with rb streetheader/presilencer/2.5" single exhaust. 150k
so for the past month and a half, my car has been burning 1 qt every 600-700 miles. I drive 500-700 miles a week for work and have been keeping track and doing regular oil changes with 20w50 castrol conventional. my o2 sensor is not hooked up yet on the header since I need to get the one in there out and its stuck. I just daily drive the car, maybe an hour total a week of spirited driving.

other day I get to work, car is fine. I'm sitting in my car a few minutes and start smelling oil. I get out, look everything over. no leaks. I start it up, oil buzzer comes on. it was fine before and I added a qt maybe 250 miles ago? no oil on dipstick at all so I throw in a qt, checked the level. had to throw in another qt to get it halfway on the dipstick between full and low. car drives the same. no smoke other then from my flooding on start up (leaky injector, white smoke) then its gone. oil psi the same, temp the same. the smell seems to be only in the car. I was thinking the oil control rings are going but could it be the rear main seal letting oil into the trans? clutch feels the same so no oil on it I can feel anyway.

sorry for long post, giving you all the info I can. I drove 50 miles home and my oil level was still halfway so it "stopped" burning excessively now? what should I be worried about here. saving for a rebuild.

 

oh, I don't smell the oil smell while driving. even with the windows both down. just after I shut it off it becomes apparent after it sits a couple minutes.

 

damn, everyones still A.D.D. on this forum and won't read threw my post. I knew I should have made it shorter. lol, anyone?

 

That sounds quite strange.. Probably the oil control rings. I don't think it is your main seal [you'd see the oil drip out of the very front of the transmission]

Also, you should get that O2 hooked up - fuel economy is nice ^_-

 

^ya, I figured my main seal theory was kinda wack since there is no seal between the engine and trans but I can't figure out why the smell is only in the car. its not like I dumped oil in there or something. idk, I've been looking at things and it definitely has to be internal but the only thing I can think of for the smell only being in the car is something coming through the shift boot. hmmmmm, well rebuild on the way anyhow.

this is my daily/drift car. mainly a toy but since my daily impreza is down with rod knock, the FC gets me to work. I don't really care about the o2 sensor.lol, its not like I get great mileage anyway, whats another 2 mpg? I'll get to it eventually, winters coming and I need my impreza up and running so the FC doesn't die from salt. (was meaning to undercoat it again but didn't get to it this year. too busy)

 

You have a fuel leak.

Do not drive your car until you've eliminated the latter. Could be something simple like an O ring or donut at the injectors, could be a fuel line starting to go at the fuel rail. or the dreaded pulsation damper failure. In all cases, the fuel system is still pressurized causing the leak at one of those places.

I had that 'oil' smell, drove me nuts trying to find it. It turned out to be a failed rubber donut at one of my secondary injectors.

 

well I know I have a leaky injector so maybe. doesn't smell like gas at all but I'll take your word for it and look over the fuel system. the dampener does like to go out on the s4's I think more often then the s5's, no? thought I read that somewhere. I have to keep driving it though so I will have to put a fire extinguisher in the car. I'll try to get rides to work as best as I can but I have no other car or much money. this sucks.

 

figured I'd update. checked the fuel lines from the tank to the engine, they seem okay but need replacing (planning on replacing when I t2 swap anyway). I took part of the motor apart to inspect the injector o rings and pulsation dampner. nothing seems "wet" (might have burned off though) and the smell isn't in the viscinity. BUT the smell has also left the car and it is now consuming oil in a more normal manner. so maybe a seal somewhere got stuck/unstuck and I got away scott free? seems improbable but idk. car will be put away for winter shortly and t2 swap parts to finish my block will be sourced over winter and spring. I'm hoping to have the car last until I find another daily or fix my impreza.

 

I'm reviving this after never really finding a fix. it was directly after I removed the stock exhaust and manifold and replaced it with a racing beat street header and rb presilencer to 2.5 all the way back, single exit. So that is not coincidence.

Something new occurred to me, could it be a failed/stuck thermal pellet? I put in 1 qt every 600-700 miles which previously was 1 qt every 1500-2000 miles on the stock system. going to be getting the car out to work on, needs a new fan so might do the tauras fan conversion since I'm planning on a v mount turbo swap in the future. the oil issue was getting to me though, I suppose that its just old and I beat on it too much as it is something internal I suspect to the oil system. I have bought new injectors, banjo bolt mod for the dampener, and o-rings for those so I will see if that does anything for me but from previous inspection I don't think thats where the problem lies. I can fix that leaky injector though so thats a plus.

one more thing, I have an s4 so that means I have a chain driven pump right? the o2 sensor being unplugged wouldn't have anything to do with the amount of oil going into the engine would it? it just depends on the amount of throttle input I think? not sure on that...

 

Its probably bad oil control rings, the higher you're revving the more smoke you'll see come out the exhaust.

Which means if you're a very spirited driver like me and most other 7 owners, you'll burn a lot more oil than someone without this problem.

Other than increased oil consumption having bad oil control rings shouldn't cause you any major problems, hopefully it doesn't get worse.

The o2 sensor has nothing to do with oil, having it unplugged will probably just give you worse gas mileage , and all rx7s have chain driven oil pumps.

Rotary >Pistons

 

^I have even driven the car "normally" for quite some time to diagnose the problem but the consumption seems the same. meaning I drove it like an old person, shifting before 3K, non spirited acceleration. So spirited driving isn't the problem but I am settling that it more then likely is the rings. I don't get hardly any smoke though. there is a very small hint from the tail pipe but it does not get worse and it is hardly noticable and only present under hard acceleration (like downshifting to 2nd or 3rd and being at like 4-5k rpms accelerating hard to pass or something). its just a puff though thats very unnoticable as I have seen it myself letting a friend drive my FC and following. I guess my t2 swap can't come soon enough. need to rebuild it. thanks for the input.

also, I thought s5 oil pumps were electrical. I guess I misunderstood and maybe that the signal is electrical vs mechanical on s4's. I have an s4 though so I know its on a chain on mine.

 

/\..you are thinking Oil metering pumps.(S4 Mechanical,and s5 electrical)
The Engine oil pump is different.

 

whats the difference between the metering pump and the engine oil pump? I guess I thought it was the same thing so where is the engine oil pump then what does the metering oil pump do?

 

The engine oil pump is beneath the front cover and pumps oil through the motor.
The MOP is located externally on the front cover and pumps oil through four plastic lines into the combustion chambers.

 

^thank you, now I understand. I didn't realize that there was another pump other then the metering pump. still haven't torn into my rebuild yet, maybe I should reread my manual as its been awhile (although I am fully capable of doing the bare block assembly. front cover still needs some research I guess).

 

so what was the problem? oil control rings u would see a lot of smoke...

ohh another "oil" smell in the car, ive seen is if the shifter rubber boots are damaged, or cracked, and gear oil in the shift tower when it gets warm, can cause smells to come into the cabin from the trany.

gear oil smells different than engine oil though. but that might be something to look at.

 

I never answered about that oil smell in car? thought I did (I recently revived it without rereading it all.). I think the smell of oil in the car stemmed from transmission fluid leaking slightly all the way up my speedo cable. broke my speedo as well since it has some trans oil in it now :/. I have not disassmebled my block yet. I'm just going to drive it until it dies. I have a t2 rebuild on the side but funds have not allowed me to purchase the rebuild kit I need. I don't see it being anything other then the rings though. my coolant is oil free so I'm settling for the rings.

I'm not seeing lots of smoke is the weird thing but it must be being burned up. I have checked for leaks many, many times and found nothing. the engine bay is filthy (how I got the car) but nothing new or wet at all. gonna clean it on rebuild. my car is far from prestine. its a project for a poor man lol. the oil consumption pretty much coincided with me putting on my rb header, pre silencer, and 2.5" exhaust. or maybe it is just old and it was time. car is parked for winter here in VT. (nov-april usually pending weather) I'll be getting her out soon so I'll see what she has left in her life. its got 150k miles I think? I have not been easy on her and judging from the rear tires in the back being barely treaded perreli's when I got her at a dealership, the previous owner wasn't either. its not in great shape so I get the feeling that it was a fun beater sports car previous to me. I daily drove her for 4 dry seasons though and only replaced a fuel pump, rebuild the starter and alternator, and a headlight switch. this year though I need a clutch for my fan and a new wiper switch. not too bad for its shape and at 26 years old. I also replaced the rocker panels which were rotten. its a base sport model so wanted to save it (the no sunroof, 5 lug, no pwere anything model).