Hi everyone, I can't seem to make sense of why my car is burning an abnormal amount of oil. Hoping for some input.

Relevant parts of the setup:
-*New* 13B-REW (completely stock as built by Mazda)
-*New* EFR 8374 IWG w/ Turblown kit
-Running OMP (carry over from last engine) along with premixing 0.5oz/gal of 93 octane

• Oil injector vacuum lines vented to atmosphere
• Oil injector settings carryover from PFC 5.08 software version

-Both vent ports on oil fill neck routed to oil breather can
-Per your typical single turbo conversion, all emissions deleted (aside from fuel vapor purge control)

Startup and break-in procedure:
Before the engine was cranked, I placed small amounts of oil into the combustion chambers via the spark plug holes and primed the turbo with oil. I turned the engine over (with starter) several times to make sure oil made its way thru the engine and turbo. After that, it started and idled smoothly. I let it come up to operating temp and shut it down several times while I worked to resolve small leaks and get the cooling system bled. After that, I put about 50-75 miles on it keeping it under 4k RPM and absolutely no boosting. I changed the oil and have since put somewhere around 700 miles on it. Engine is not revved above 4k RPM and I do not boost more than 3-4 PSI during any driving. I wanted to hit 1000 miles of light load driving before getting into any real boost and tuning.

Symptoms:
Cold starts yield more smoke than I believe is typical, but it clears up after 20 seconds or so (video link below). Outside of that, it only seems to burn oil while under load. Free revving does not produce smoke. It intermittently smokes heavily when accelerating from a stop (maybe two or three times during a 60 mile trip; unfortunately, haven’t captured on video yet) – when it does this, I leave a dense trail of blue smoke behind me. Outside of those occasions, it tends to smoke lightly close to half of the time when accelerating (video link below). The other times when driving, I do not notice any smoke. Since the last oil change, the oil level has worked it’s was down from being full on the dipstick to approximately the half-way mark. This would equate to ~0.9qts in < 1000 miles. The engine has no oil leaks.

Troubleshooting:
Oil must be consumed by either the engine or turbo. The turbo is dry – no oil in the compressor housing, charge piping, and the turbine looks clean (pic below). For the engine, I don’t believe an OMP malfunction could contribute to the intermittent smoke trails (maybe light smoking, but I don’t think the system has the capacity to make trails of smoke). I am worried that the oil control ring(s) may be damaged somehow but hate to think that’s a possibility considering the engine is new.

I swapped in some fresh spark plugs and put around 75 miles on them before I pulled them out to look at. The pictures of the plugs below make them appear darker than they actually are - the T1 vs T2 picture represents plug color most accurately. Note that I am running rich cruising AFRs of mid 13s:1 and very rich when at anything above atmospheric (low 11s / high 10s).


Any insight would be greatly appreciated!



Cold start video:






Under light load:

Watch bottom left hand area of the frame. Little hard to see due to the vehicle speed (may need to turn video quality up), but oil smoke is coming from exhaust.




Turbine housing:



Plugs pulled:



T1:


L1:


T2:


L2:


T1 vs T2 - Note the discoloration in insulation around the center electrode on T1, along with more of a residue on the ground electrodes

 

Do you have a picture of your catch can setup?

That's baffling for sure.

Dale

 

Cold start and under load blue smoke seems to indicate that it's only burning oil in elevated oil pressure conditions. Usually the component that isn't happy with high oil pressure is the turbo.
If I had to take a guess in the dark it could either be the turbo seals are bad or the turbo is receiving more oil pressure than it's happy with.
What turbo are you running? Restrictor plate? Is there oil in the intake? Maybe the oil drain from the turbo is backing up and causing pressure buildup in the turbo?

Edit: Just saw the picture of the turbine housing mentioning the turbo is dry. That really is quite puzzling.

 

Thanks for the response Dale.

I'm running two 3/8" lines from the fill neck to a catch can vented to atmosphere. I capped the port on the intake manifold that previously utilized the PCV valve.

BTW, the engine bay is still a work in progress, so don't think too poorly of me




My first though was turbo as well. But it doesn't look that way here. The EFR turbos have integrated restrictors, so I can't go wrong there. I'm utilizing the drain line that came with the kit and there are no kinks or uphill portions.

 

Yeah, catch can setup looks solid. May want to do a test drive with the oil fill cap off to verify and see if you get any smoking.

Did you install the engine un-opened or did you open it up to modify anything?

Unfortunately at this point I'm leaning towards something being up with the engine. Typically if it's a bad turbo you'll see a black, wet turbine wheel. Been there done that.

Dale

 

I'll give it a try with no oil fill cap to see if anything changes. But I have a feeling that the current setup is about as well vented as it can be without also venting the rear turbo oil drain port.

I installed the engine un-opened. I figured Mazda knew what they were doing, but I am now wondering if that was a bad assumption..

I am hoping that I am overlooking something here. Has anyone had a failed OMP cause large amounts of smoke?

 

Not sure about under load, but my new Mazda engine/turbos also smoke a bit like this on startup. Never thought much of it though. Bummer guess I need to keep a closer eye on it...

 

Smoking doesn't really look too bad but I do see it. Some motors do it more than others. What fuel system do you have? Is the car tuned? Excessive fuel can often be mistaken for oil smoke. Are you running a cat?

 

The video of it rolling doesn't show it very well. There are times when it smokes to the point where it's embarrassing. I will put some more miles on it and see if I can capture it on video to post here.

I'm running new OEM 550CC primaries with ID2000 secondaries. The car is on a very conservative break in tune I made. I can try to pull some fuel out but I don't think that's the problem - I can smell oil when I run with windows down and accelerate. No cat - just resonated mid-pipe.

 

Are you sure two 3/8" lines are big enough and not restricting flow thus creating excess crankcase pressure?

 

In for updates
I've got just about the exact same setup as you (just without the catch can) and I also get quite a bit more blue smoke at startup than I anticipated, way more than my old engine did at least. I kind of figured that if it was an engine problem I'd just live with it as long as I didn't notice anything else fishy. Not a fan of the idea of taking my engine back out and apart, now that the weather's looking nice!

 

Stock pcv elimianted?

 

The OD of the two ports on the oil fill neck is actually a little smaller than 3/8" (must be 9mm or so). I had to crank down on the hose clamps to get a snug fit on the ports. Not really practically to go any larger than a 3/8 ID hose IMO.

My last engine had an unknown amount of milage on it (certainly upwards 15k ) with some pretty tired twins and never burned oil like my new setup

Yes - nipple on intake mani is capped and both ports on oil fill neck vented to catch can.


I put some more miles on it today and never it never left a heavy trail of oil smoke - only very light blue clouds. As I approach the end of my 1k mile break in period, I will soon be giving this engine some actual boost and working on the tune. If it ends up smoking like a locomotive while in boost, I suppose I'll have to pull the motor.

 

Same situation for me,turned out to be a bad turbo after car was being worked on

It took a few years and I'm guessing the seals let go despite trying to keep them in good condition, streaks of blue smoke on boost was the give away.

 

I would wait until I had the actual tune and not a break in tune. I had a similar situation with my motor but once it was tuned properly it went away. I also had this issue on my old motor and that time it turned out to be cheap premix.

 

Based on your photos looks like the engine to me. You can see oil on the crush washers on the plugs, and the fact that turbo inlet/outlet on compressor are dry = engine almost everytime( seeing as the crankcase vent is open, and oil levels in pan are normal). I had another customer recently have the same issue, and it was his new mazda block in the end.

You can play it safe, get it tuned, then swap turbos, or try and run without a turbo( a little difficult for most) to diagnose further...

 

https://www.rx7club.com/3rd-generati...3brew-1144484/

 

One of the main things I was hoping to find from this thread was if others have experienced this with a new Mazda keg - so thanks for confirming that things like this can/do happen.

I have pulled the plugs a total of three times since the engine has been running and every time I have noticed oil on the crush washers. I don't recall having that with my last engine.

I have cleaned up the fuel map and am pretty spot on with my target AFR table for everything under 5 PSI (still haven't boosted higher than that). The car runs great with no stumbles or overly rich areas. I don't think the tune as anything to do with this. I'm also observing that the car doesn't have to be under much load at all to smoke. I was slowly accelerating in first gear from a stop light yesterday and smoked out the car behind me. It then cleared up by the time I was in third gear.

A new finding is that the car also burns oil intermittently on deceleration, too...


I posted a picture of the turbine in my original post but should have included the compressor outlet - so here is that:

 

Unfortunately it's looking more and more like it's something with that engine. I imagine there's a warranty on the engine, may have to start looking into that.

I typically suspect the turbo before the engine but the fact that the compressor side is bone dry and you are seeing oil on the plugs is a big clue. The only way the turbo could get oil on the plugs is from the compressor side.

Sounds like something is up with the oil seals in the engine.

The only last thing I would maybe do is drive around with the oil fill cap off. If you are still getting smoking, that would be 100% the engine. That just totally eliminates something with your catch can setup being a problem.

Dale

 

my friend had one once where the vacuum to the metering nozzles made a big difference, i forget how the thing ended up but if it was hooked up like the kit said, it would smoke like crazy

 

If weather permits, I'll remove the fill cap later this afternoon and take it for a drive. I'll report back.

That is interesting. This thread contains some good information on how the oil nozzles function and how they should be plumbed:

https://www.rx7club.com/3rd-generati...d-open-846007/

I have vacuum lines on each nozzle which run to a T fitting which is then vented to atmosphere.. not sure how my configuration would be contributing to the problem.

 

yeah the stock set up plumbs those lines in front of the turbo, and most of the time its just filtered atmospheric air. i have seen it make a difference, although i don't remember why/what

 

I think if you had them plumbed into vacuum or boost that could be a problem. They are just supposed to be vented to atmosphere.

Dale

 

Dale, I removed the oil fill cap per your recommendation and took her out for a drive. Unfortunately, I did not notice any difference. There was no evidence of excessive crank case pressure by means of oil residue on the underside of the hood or anywhere in the area.

If anyone can reason how this might not be a problem with the engine itself, I'm all ears.

Video for reference:

 

Stock the oil injector vacuum lines go to the primary turbo inlet duct so they see constant vacuum and no boost.

It would seem like having vacuum at the top of the oil injector would prevent intake stroke vacuum at the engine end of the oil injector from drawing in excess oil.

Try hooking up oil injector tops to constant vacuum or at least a regular vacuum nipple with a check valve inbetween to keep boost out of oil injectors and see if the excess oil consumption continues.