Oil smoke when FT. Corksport Turbo

[DjSinestro]

Hello and thanks for any help troubleshooting this issue. I appreciate you!

I recently replaced the stock turbo with a corksport drop in. Ran a tune through Freektune. It was doing this exact issue before I replaced it so I am of the belief it is not the turbo.

When hitting the gas full on in my 2006 MS6 I see a huge plume of smoke (black/grey). It doesn't do this any other time and if I don't full throttle it I don't lose oil (I purposely didn't hit the gas for 3 weeks and the oil dip stick showed no change. then I did one week when I hit FT once a day and went through half a quart).

What might cause this?

[Vansquish]

Originally Posted by DjSinestro Hello and thanks for any help troubleshooting this issue. I appreciate you! I recently replaced the stock turbo with a corksport drop in. Ran a tune through Freektune. It was doing this exact issue before I replaced it so I am of the belief it is not the turbo. When hitting the gas full on in my 2006 MS6 I see a huge plume of smoke (black/grey). It doesn't do this any other time and if I don't full throttle it I don't lose oil (I purposely didn't hit the gas for 3 weeks and the oil dip stick showed no change. then I did one week when I hit FT once a day and went through half a quart). What might cause this?

Does your oil smell like gas?

[DjSinestro]

I haven't noticed it. I'll check in a bit when I get a break.

[Vansquish]

If so, you probably have worn piston rings and gas is sneaking pas them and into the sump.

[Jeff23spl]

well, without leak down and compression test it is hard to say where that smoke is coming from.
Without afr reading under load, it is also hard to figure out if it could be fuel or oil...
By the way, the CS turbos i know about are larger than stock with needs for supporting mods. It bolt there but if you don't upgrade around, you are in trouble....
You need to be aware of MAP sensor against tune
And also HPFP, you may run into fuel pressure drop and when the ECU see that, as a first mean of defense, it trigger a very high opening time on injector to flood the engine. That wouldn't drop the oil level but it is something to look for because it isn't good at all.

And it is very likely that a worn engine under high boost will generate more blow by and without good venting, that oil will return to the intake to be burn or directly into the exaust thru turbo seals...

[DjSinestro]

Thanks for the response.

I had a local mechanic do a leakdown and got 7,12, 12 and 10. Compression is fine between 145 and 150 on all cylinders

[DjSinestro]

Originally Posted by Jeff23spl well, without leak down and compression test it is hard to say where that smoke is coming from. Without afr reading under load, it is also hard to figure out if it could be fuel or oil...

I have an accessport. Does it have that reading?

By the way, the CS turbos i know about are larger than stock with needs for supporting mods. It bolt there but if you don't upgrade around, you are in trouble....

We bought the accessport and ran a tune through freektune. also
replaced the inlet pipe with a bigger corksport
https://corksport.com/mazdaspeed-turbo-inlet-pipe.html
along with a grimmspeed ebcs (Using it in 2 way mode)
https://www.grimmspeed.com/electroni...-mazdaspeed-6/
and finally got a Max flow fuel pump internals and 3.5 bar map sensor

And it is very likely that a worn engine under high boost will generate more blow by and without good venting, that oil will return to the intake to be burn or directly into the exaust thru turbo seals...

Engine has 110000 miles, so maybe this?
The turbo is new though, so shouldn't the seals not be allowed through?

It feels like your thoughts on the oil returning to the intake has merit. Is there a way to check that? Thank you for this!

[DjSinestro]

How could I implement "good venting"?

[Jeff23spl]

Originally Posted by DjSinestro How could I implement "good venting"?

you can work on the pcv system there is a lot and a lot of thread about it. Including a dual pcv plate and occ....

[DjSinestro]

Originally Posted by Jeff23spl you can work on the pcv system there is a lot and a lot of thread about it. Including a dual pcv plate and occ....

Thank you! I appreciate you taking the time to point me in the right direction.
I am new to the forum. Where could I see this thread/section?

[Jeff23spl]

make a google search including Mazdaspeedforum and what you are looking for...in this case:
-OCC install
-Dual breather/vent
-OCC VTA
-Blow-by
-PCV or crankcase ventilation system
etc

[Speed3ster]

I went with a breather and it helps! next is a PCV vent system!!!

[Vansquish]

Originally Posted by Speed3ster The Stock turbos cant handle the oil being put through them, the seals are crap and under full boost oil gets past it. Mine did the same, I have a CST5 and I really don't get on it much and when I do, yea she clears her throat if you will and a small smoke screen is deployed but a second full send and nothings there. Do you have a catch can or a vented valve cover? Are your plugs gapped correctly?

Plug gaps do not have an impact on whether oil gets through the turbo seals.

The same is generally true of the vented valve cover and catch can. Neither of them changes the pressure differential across the turbo (from the cold side to the hot side). Therefore, if your turbo's seals have failed, then none of what you asked about is relevant to the discussion.

The only things you can do are change the amount of oil getting to the CHRA of the turbo (banjo bolt) and/or change the pressure differential across the turbo by altering the intake and/or exhaust system.

Furthermore, these are direct-injection engines which generate significant amounts of particulate matter as part of the exhaust. That's part of why you see a black plume when you get on the throttle.

[DjSinestro]

Originally Posted by Vansquish Plug gaps do not have an impact on whether oil gets through the turbo seals. The same is generally true of the vented valve cover and catch can. Neither of them changes the pressure differential across the turbo (from the cold side to the hot side). Therefore, if your turbo's seals have failed, then none of what you asked about is relevant to the discussion. The only things you can do are change the amount of oil getting to the CHRA of the turbo (banjo bolt) and/or change the pressure differential across the turbo by altering the intake and/or exhaust system. Furthermore, these are direct-injection engines which generate significant amounts of particulate matter as part of the exhaust. That's part of why you see a black plume when you get on the throttle.

Very indepth! Thank you for the information as I am fuzzy on how the specifics work.

I wouldn't want to mess with oil pressure/amount going to the CHRA. I would be too afraid of starving it and burning it out.

Altering the intake/exhaust. What do you mean by that? As in what alterations could you see reducing the amount of oil consumed when going full throttle?

[Vansquish]

If you increase restriction (reduce the internal diameter) on the exhaust side of the turbo, the pressure differential across the turbo decreases as well. This is primarily because the turbo is not capable of flowing as much air/exhaust under such circumstances (and also because the turbo will produce less boost).

So, basically, if you run a stock downpipe with stock catalytic converters, and a stock-ish sized intake, no matter how hard you try, the OE turbo will only be able to produce around 20-21psi "efficiently".

[DjSinestro]

Originally Posted by Vansquish If you increase restriction (reduce the internal diameter) on the exhaust side of the turbo, the pressure differential across the turbo decreases as well. This is primarily because the turbo is not capable of flowing as much air/exhaust under such circumstances (and also because the turbo will produce less boost). So, basically, if you run a stock downpipe with stock catalytic converters, and a stock-ish sized intake, no matter how hard you try, the OE turbo will only be able to produce around 20-21psi "efficiently".

That is about right. I hit around 21psi.
So, to clarify, you are saying if I get a bigger intake and exhaust, I will see less smoke and burn less oil?
Cause...that is awesome. I could use that to convince the wife to let me buy those parts and have more boost.

[Jeff23spl]

Originally Posted by DjSinestro That is about right. I hit around 21psi. So, to clarify, you are saying if I get a bigger intake and exhaust, I will see less smoke and burn less oil? Cause...that is awesome. I could use that to convince the wife to let me buy those parts and have more boost.

I think you didn't get it right. Bigger intake and exhaust will just allow more air flow and potential more power.
About the oil burned, the less restriction you have on the exhaust, the more chances it can leak from turbo seal. Oil take the easiest route and if your engine bottom rise in pressure higher than the exhaust pressure (blow by) some oil will find a way thru the turbo ring gap (seal) and make smoke.
And in the same direction, if you increase engine flow without enlarging the turbo, the only way it can follow, it is by spinning faster. This create more heat and more wear.....

[Vansquish]

Originally Posted by DjSinestro That is about right. I hit around 21psi. So, to clarify, you are saying if I get a bigger intake and exhaust, I will see less smoke and burn less oil? Cause...that is awesome. I could use that to convince the wife to let me buy those parts and have more boost.

You need to read more carefully. I wrote precisely the opposite.

The bigger and more free-flowing the intake/exhaust are, the higher the pressure differential will likely be.

[DjSinestro]

Originally Posted by Vansquish You need to read more carefully. I wrote precisely the opposite. The bigger and more free-flowing the intake/exhaust are, the higher the pressure differential will likely be.

Thank you again for clarifying. I am not completely familiar with what some of these parts and how they interact.

So to summarize again, the more pressure exerted, the more likely oil will leak through and get burned in the combustion chamber. So, this would mean buying and installing a more robust PCV system will most likely not stop the oil from burning during full throttle.

I suspect in the end I just need to watch the oil once every 2 weeks and top it off as needed. Seems like it will run fine otherwise.

[MSMS3]

Originally Posted by DjSinestro Thank you again for clarifying. I am not completely familiar with what some of these parts and how they interact. So to summarize again, the more pressure exerted, the more likely oil will leak through and get burned in the combustion chamber. So, this would mean buying and installing a more robust PCV system will most likely not stop the oil from burning during full throttle. I suspect in the end I just need to watch the oil once every 2 weeks and top it off as needed. Seems like it will run fine otherwise.

You might also want to check to see if your present PCV valve is functioning properly. Maybe it needs to be replaced. If it is not releasing pressure, then, under high boost and high crankcase pressure oil will get pushed passed the turbo seals and out the exhaust. FYI: It is a bitch to get to, as it is under the intake manifold. It's usually best to remove the manifold to access it. While you can reach it from below, you have to release the lock to pull it out. Getting to that lock and re-locking it from below can be done but it takes patience and really tiny hands.

[Jeff23spl]

Originally Posted by Vansquish You need to read more carefully. I wrote precisely the opposite. The bigger and more free-flowing the intake/exhaust are, the higher the pressure differential will likely be.

You are right for the exhaust but i think on the intake side, it is the opposite. With more restriction (vacuum) in the inlet pipe, the more your turbo will have to work to make the same boost...

[Spectrix]

Originally Posted by MSMS3 You might also want to check to see if your present PCV valve is functioning properly. Maybe it needs to be replaced. If it is not releasing pressure, then, under high boost and high crankcase pressure oil will get pushed passed the turbo seals and out the exhaust. FYI: It is a bitch to get to, as it is under the intake manifold.

I might be wrong, isn't the PCV valve under the manifold supposed to be open at vacuum and closed under boost?

[MSMS3]

Originally Posted by Spectrix I might be wrong, isn't the PCV valve under the manifold supposed to be open at vacuum and closed under boost?

Yes, it vents under vacuum such as idle and cruising. It closes under boost. But it is under boost that oil gets pushed past the turbo seals. So, if the valve does not open when you lift throttle, the pressure does not get relieved and continues to build. In some instances, if it does not find a way to relieve pressure, it can blow the dipstick out of the tube. It more often pushes oil past the rings (blow by) or past the turbo seals. Either one of the latter causes smoke, usually bluish-black.