RE Suzuki

I've been getting some oil burning smoke comming out of the exhaust at the morning start for first 10sec ever since I've installed the mazda reman. Turbos are still good. A fellow memeber of rx7club.com has told me that it could be the oil metering pump. How do I check the cause of the smoke?

**The mazda reman that I have now has 5,000miles. It has bad coolant seal. Possibly the o-ring seal was "pinched" duing the rebuilt by mazda. I am going to have another reman installed soon, so during that time I'd like to check the cause of the "oil burning smoke" at the start. If not oil metering pump, what else could it be? Can the bad mazda reman motor be causing this problem?


mods: m2 stage 3 ecu, dp, greddy smic, arc intake,... thats about it which are under the hood.

RE Suzuki

anyone?

dgeesaman

iTrader: (7)

What color is it? (Are you sure it's oil smoke?)

10s doesn't seem like a long time.

Dave

iluvmy3rdgen

It could be smoke from burning coolant.

RE Suzuki

No its not the coolant. I'm sure its oil smoke. Its alot thicker and darker in color. (dark gray)

After the oil burns off, the coolant starts to burn since I have the pinched coolant seal.

rousu

I have been told the Rx injects oil for the rotor seals and rich mixture for the start,
so an oil-smoke experience is normal at startup. If you shut it down prior to warmup and clearing the initial load, then the car may load up an not start for you. The accellerated warmup function should help burn it off. If oil smoke goes on after a minute, then there may be a problem.
That said my Mazda reman does seem to smoke more on startup than my apparently healthy motors from the past.

RE Suzuki

oh, great.... If thats the case, i hope my other reman wont do that...

rousu

Other than looking bad, it should be good for the engine to get lube and seal at startup,
as long as it doesn't foul the plugs or cause a smog alert.

The camaflauge cloud may keep the cops from seeing you....

EKTwin93

Have you compression tested you new motor. I'd be a little hesitant to drop to a new reman in there with only 5k on the one you have now. 10 seconds of smoke isn't very much at all. What vacuum are you pulling at idle? How much coolant do you lose? It doesn't really sound to me like you need a new motor. I would be mad if I had to pay for another motor 5k after my new one.

Trexthe3rd

Oil smoke is thin and has a very light bluish tint to it, what you are discribing sounds like mostly coolant.
Where did you buy the reman from? They should have at least a 1 year and 10K warranty from Mazda (assuming it was installed and operated correctly).

turbojeff

iTrader: (30)

Oil smoke for 10 sec upon startup is normal. Usually a light blueish color, could last 20-30 sec also.

Your oil metering pump may contribute to the oil smoke but that means it is doing it's job.

cloud9

iTrader: (4)

the seal in your turbos could be going out too, that would cause your car to smoke, but if it goes away after 10-30 seconds then your just being overly paranoid

RotaryResurrection

iTrader: (8)

Why do people worry about smoke on startup? With a rotary engine, any rotary, new, rebuilt, used, whatever, startup smoke for <1 minute is normal. You have to have seen the internals of one to understand.

The rotors are hollow, and oil flows inside them, and on the bearings/shaft surfaces. All of this is suspended in mid air, obviously affected by gravity, since the volume of oil is being held up. OIl control rings maintain the oil containment while moving...keep in mind that hot oil is pretty thin really, almost like water, so it has a greater tendency to leak past seals. So then you shut down your engine, and the rotors stop, in mid air. However, the oil control rings are no longer in motion, and thus do not seal perfectly (it is a metal to metal seal). Over the course of several hours, a small amount of oil drains past them, pooling up in the combustion chamber.

It is also said that oil being injected via the OMP can sometimes continue to drain into the combustion chamber while it is not running, resulting in some of this startup smoke. However, I see this on cars running straight premix as well, so I don't attribute much of it to that.

TwinTurbo_SE7EN

sorry to bring an old thread up.

I am having similar issues with my reman. I still have a month left on the warranty. I get very little smoke (if any) for the first 10-30 seconds of startup, then I get moderate to heavy smoke from then until I drive it wround a bit. after that it will smoke a faint blue if I let it idle for a while. If I let it sit for a while then start it up after it has cooled down a little bit, it will smoke until I drive it for a minute. it is very embarrasing and I know it shouldnt smoke this much. I get 14-16" vac when cold and 15-17" vac when warm between 900 and 1200 rpm. engine is stock port and has ~7000 miles on it...it has 115+ psi on all 6 faces.

compared to my last engine this one just seems to struggle...vacuum doesnt jump around and I know what a blown engine sounds like. It has done this since day 1.

Im sick of this.

TwinTurbo_SE7EN

oh, and I havent had to add coolant since I put the engine in it in January.

RotaryResurrection

iTrader: (8)

Lots of times turbos will cause smoke as you describe, until you get it out and get the rpms up and then the smoke all but disappears until you let it idle for a while.

But, if they didnt do it immediately before the engine swap, and they do now, then it could be the engine. Your plugs can be a good indicator, so check them and add that into the elements of the diagnosis.

White_Rx7

Claim warranty before its over!!!

sorry couldn't be more helpful,

GL

TwinTurbo_SE7EN

Thanks for your reply.
What should I look for on the plugs indicating a motor issue?

I have replaced the plugs at least 30 times since I installed the engine. everytime they are a dark brown/black and look like carbon build up. I dont really know what carbon build up looks like, but if I had to guess, thats what I would think.

The turbos did not do this before the engine swap. They have a good bit more side to side shaft play than the last time I checked them with the old motor. I do get some oil in the IC piping, its not an outrageuos amount though. My oil reaks of fuel after 1500 miles. My oil catch can has this thick white foam that collects in it...along with water(Im guessing condensation). it smells like a nasty oil/fuel mix or something. I dont think I have ever seen just oil in the catch can.

Sometimes the smoke doesnt look blue really, but a somewhat thick grey/white. but it smells the same as always. it doesnt smell sweet ( I dont think...never smelled coolant smoke). and if a headlight shines through the smoke it definately has a blue tint to it. in the last 1000 miles my oil level has gone from full to half way between full and add. it really only seems to go down noticable when I have been boosting a good bit.

sorry for the long post, thanks for your help so far.

RotaryResurrection

iTrader: (8)

An engine that burns oil (versus turbos causing smoke out the exhaust) will carbon up the plugs pretty quick. Carbon looks like black chalk, basically. Normally you'll see a light coating of black carbon on the plug, with a medium tan color in the center area. Keep in mind that running a rich mix can cause the same plug fouling, carbon deposits, smoke, and gas contamination of oil that an oil burning engine can, though. It is one of those things that one can never say for sure without much experimentation.

Generally with these engines, it is a mix of all 3...stock twins, regardless of mileage, will almost always burn some oil out the exhaust (and often through the intake as well). The turbo rotary by nature runs quite rich, so you get some carbon and smoke added there too. And its quite possible that the engine itself is burning some oil too. It's usually hard to seperate the 3. Not to mention you can have an OMP issue or a crankcase ventilation issue adding to those factors.

TwinTurbo_SE7EN

ya, I think the majority of my plugs were fouled because of a bad FPR...lots of fuel pressure and very rich. my idle is about 11.1 cold and between 11.4 and 11.8 warmed up. I have a wideband. I only have the catch can run to the oil filler neck and the second nipple capped. I tried to lean out the idle to 12.0-12.8 and it just died on me..maybe it like a rich idle or maybe my idle screw is out of whack for that lean of a mixture at idle.

I used to see very faint blue smoke from the exhaust with the last motor...you would have to be right up on the exhaust to notice it. now I just kind of wish thats all it would do. I think my next step is to test my engine with a know good set of coils and then call in for a warranty. I am going to try taking the turbos off and seeing if there is alot of oil build up pre-turbo. maybe see if it smoke with the turbos off. the only thing I havent ruled out are the turbos and the coils.

so running rich would cause similar symtoms as far as smoking? is 11.1-11.4 rich enough for this? It did get quite a bit better once I replaced my FPR. before that it was bad...really bad.

I also have a bad oil injection nozzle...with the vacuum lines off one of them sucks vacuum and the other doesnt. Im not sure which one is at fault...Im thinking the one that sucks vacuum. I have run line to the primary turbo inlet and the nozzle that sucks has a check valve inline so it still gets vacuum from the primary turbo but doesnt go the other way.

TwinTurbo_SE7EN

btw, my idle smoke is definately not black smoke.

RotaryResurrection

iTrader: (8)

You can disconnect the OMP lines at the OMP and let the engine run a while (until all the oil is sucked out of both lines) to eliminate that as a possible source.

You can take the oil cap off to eliminate that as a possible source.

The only way you can get an idea of whether the turbos are responsible or not is to pull them. IF the passages PRE turbo are clean (tan/brown/light black) but the passages POST turbo are solid black, then you know the turbo is adding a lot of oil and smoke to the exhaust while the engine is burning pretty clean.

IF all passages are dark from the engine ports out, then the engine is responsible for most of the smoke...be that because of an OMP issue, a crankcase pressure issue, a rich issue, or an oil control ring issue, or some combination of them.

That's about all I can say.

I wouldnt think the coils would have much to do with it at all...generally coils either work or not, and unless they misfire under load, they are doing their job. For purposes of this discussion, spark is one of those things that you either have it or you don't most of the time, unlike fuel and compression which can vary in intensity/amount.

TwinTurbo_SE7EN

Thanks for the help. I really appreciate it.

RotaryResurrection

iTrader: (8)

Also, a turbo that dumps enough oil through the intake tract can naturally cause the engine itself to burn dirty and smoke too...so that is another explanation for dirty ports. But, this generally only happens when under boost or accelerating/decelerating, and not really at idle since the turbos dont spin fast enough to expel any oil into the intake at that time.

RE Suzuki

I've finally got another mazda reman with the warranty. It took......almost a year! I have another omp to be installed along with the reman. I'll see what was causing my car to puff out the smoke!