mono4lamar

iTrader: (32)

hey guys... new motor and pretty much everything else is new (external seals). i have about 1400 miles on the setup and i have a weird problem now. if i do wot or heavy throttle theres blue smoke pouring out behind me after i let off the throttle (decel). i also have a hunting idle that i've had all along that either idles at 700-800 or 1400 it does it when it wants after i get off throttle. the smoke just started happening. does any one have any input? im thinking it could be vaccume related for the idle but im not sure about this blue smoke. hoping someone has some experience with this problem.

i did have an oil leak on the motor that i finally found. its from the smaller vaccume port that aims down on the filler neck... does anyone know what vaccume line is suppose to go there and where the other end is suppose to be? i will take some pictures of the filler neck tomorrow night to help show. thanks in advance for any help on this!

-Lance

Montego

iTrader: (1)

Most likey you have leaky turbos. Another culprit could be that you have OMP issues.

your hunting idle can certainly be vacuum related. Start the car and spray carb cleaner all around the vacuum hoses, UIM, and IM if your car changes idle radically you found the area of the leak.

Scrub

iTrader: (25)

Sounds like your oil system is being pressurized. Are you forgetting the check valve that goes to the oil filler neck?

matty

either turboes or pcv valve. this is a fairly common issue actually.

i have the same problem with my car that just showed up late last summer. i plan to check the pcv come spring but i have a feeling its the turbos. they still pull amazingly strong but i have been running 15psi CONSTANTLY for 5 yrs. so who knows. Do a search and u will see how to check the pcv....or just replace it. i think i am gonna juts replace mine.

take a look here:
https://www.rx7club.com/showthread.p...ighlight=decel

mono4lamar

iTrader: (32)

i have an r85 on there so it cant be turbo related. i have the pcv valve in to the top of the filler neck... its suppose to restrict one way right?

i'll take pictures tonight of the filler neck... does anyone know where the other port that faces down is suppose to go. its the one below where the pcv valve hooks up to.

any other ideas?

dubulup

intake (pre turbo) vacuum.

I run it thru a catch can before the intake

mono4lamar

iTrader: (32)

why would i just all of a sudden have this problem happen? could i have blown the pcv valve?

matty

ummm YES. didnt i say that already? take the thing off and test it or juts get a new one.

do a search as well. ther eis alot of chatter about this topic.

dubulup

just cap the PCV...95's eliminated it all together, probably for the reason you describe.

Scrub

iTrader: (25)

Like I said before it sounds like the crank case is being pressurized, one of the vacuum lines is either hooked up to a pressure source which should be vacuum or a check valve is blown. It's possible that the vacuum hose coming off the bottom of the filler neck is going to a pressure source. That hose sould be run either to a catch can and then to the intake pipe somewhere, or directly to the intake pipe.

point5chink

my bet is that it is the oil control ring inside your engine. If it was the turbos, it would most likely smoke on accel not on decel (heavy vacume). Basically the vacume is sucking oil through the ring into your engine. I just had my engine repaired at pineapple racing because of this (~1300$ total). It will probably get worse and worse, and then it will get bad enough that it will leak into your engine while you are parked over night and when you start it up, more oil smoke. This is what happened to me on a fairly fresh rebuild. I hope its something simpler for your sake, but i would look into this. The good news is it wont do too much damage aside from making your plugs look like they were thrown into the sun. If it gets really bad there might even be oil on one of the lower plugs.

mono4lamar

iTrader: (32)

^ what were the conditions with your "oil control ring" was this an old engine? like did it just one day start smoking? my motor has 1400 miles on it so it would be weird for it to start doing it now. the only thing is i had some blue smoke on startup nothing bad but if you looked you could see it was blue smoke. i did not think to much of it. i thought the omp was just injecting some extra oil because of startup. cant you program that in?

point5chink

engine prolly had 15k on the rebuild, 78k total miles. I expect that it could happen any time since mine should have only been 15k miles old.
Heres a link to my thread where i asked the same question, and go the same answer im giving you. Sending it to pineapple confirmed that it was indeed the oil control ring.

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/smoking-startup-decel-526680/

GoodfellaFD3S

iTrader: (213)

If it's an oil control ring failure, it will be the first time I've heard of it happening. If your engine builder doesnt know what the hell he's doing, I suppose it's possible. There is a specific method to orienting the oil control springs and rings. You could have 'spun a bearing,' in effect, in your oiling system. Hopefully that isn't the problem---who built the motor?

I would definitely look into the rest of the system first. From your first post it sounds like you have nothing on the nipple pointing downward on the filler neck, meaning your crank case is vented. Smoking under that condition isn't good.....I recommend plumbing that nipple (along with your OMP injectors) to the area between the air filter and compressor housing, so that they receive filtered atmospheric air (but not boost or vacuum).

Edit: I see in your sig that Chris Rogers built your motor. By all accounts the man knows his ****, so I highly doubt it's an oil control o-ring problem

mono4lamar

iTrader: (32)

^ so rich your saying that the nipple pointing down should go to my compressor cover? two weeks ago when i found the oil leaking from there i capped it off and used a small zip tie to make sure it would stay on. yet i still have the smoke. i wish i didnt have so much schoolwork to do i would be in my shop playing. thats why im trying to get a list of things to check and do it all at once. does anyone want to pop there hood and see where their vaccume line is going to from that nipple on the filler neck (the small one pointing down, not the big horizontal one). thanks guys!

GoodfellaFD3S

iTrader: (213)

No one has to pop their hood for you, I'm telling you the correct way to hook it up, and this may stop your smoking problem .

Run a 1/4in (or 6mm) line from the nipple in question to your compressor inlet---between your air filter and compressor cover. You'll most likely have to drill, tap, and thread in a fitting, I used a 1/8 NPT bung. You can see the blue vacuum line in my sig, in this case it's for the oil metering system, but it should work for you---it'll depressurize your crankcase. If you still have smoking problems after that, I'd start looking at the turbo or worst case the engine, but I wouldnt be worried. This should fix your problem.

dubulup

At least uncap the nipple...that will relieve some pressure. are you sure your PCV is pointing in the correct direction as well?

Scrub

iTrader: (25)

You should try looking at the vacuum diagram mate. Surpised you haven't yet....so I took the liberty of outlining the line that goes from the bottom of the filler neck to the turbo if you can see it in the picture below....

mono4lamar

iTrader: (32)

^ that diagram is messing with my head... but i see what your saying. i have my compressor cover inlet already tapped. the line from that is routed to the tops of the oil metering squirters.

you sure it goes like this rich? i drove the car for 1400 miles with no smoking so i dont see how this would all of a sudden make the car smoke. yet theres no way could leave that port uncapped cause it sprays oil all over the motor.

maybe i should run a catch can setup i really dont want to but that could cure my problems. what would cause such high crankcase pressure?

i'll have to check that pcv first as that might be letting pressure back into the filler neck and squirting oil out of that port... cause i have no loose lines meaning i dont think i ever capped that port off.

the motor is surely solid and the turbo itself has less than 4k on it so thats most likely in good shape unless i threw something out of the motor and it got ripped to pieces. so if my turbos shot theres also dammage to the motor at this point.

thanks for all the help so far guys it means a lot!

GoodfellaFD3S

iTrader: (213)

What you're experiencing is odd, b/c I currently have that nipple on the filler neck uncapped and venting my crankcase right now, with zero oil smoke out the tailipipe. I'm also seeing zero oil coming out of the nipple......

Scrub

iTrader: (25)

Rich, it can be disconnected also.... But the crank case should have some sort of ventilation, preferably vacuum assisted via the compressor inlet pipe. There are other ways of having vacuum assist but it involves a little more work. The line I circled is actually the one next to the nipple that goes to the oil injectors....it's not colored in the diagram.

dubulup

uncap the nipple and run a catch can like FD3BOOST

sorry for the ugly photo, but it will keep from blowing oil in your bay and damaging your turbo.


something seems to be wrong with your PCV as well. IF you have both nipplpes capped...that's when your problem occurs.

ptrhahn

iTrader: (9)

Rich,
I thought the whole point of running a catch can was so that you didn't have to run the line from the filler neck to the turbo inlet (or to the UIM).? Is this what you're talking about hooking up?

I actually get this puff of oil smoke too, but it's only on track and only when I let off to upshift at the track-out point on long hard right-handers. I can't replicate it going in a straight line or on the street.

mono4lamar

iTrader: (32)

im going to have to check out the pcv valve first... that might be my whole problem. bringing a line to my compressor cover is not going to solve my problem, but to allow some oil to go to my compressor cover then. that nipple is leaking. hopefully the valve is the problem. if not im going to run a catch can.

GoodfellaFD3S

iTrader: (213)

I'm aware of all this, Big Dan . Getting atmospheric assist from the comp inlet is only necessary if you are having oil smoking/blowby problems. In my current case, simply venting it/leaving it uncapped seems sufficient---no smoke at all.