Hi everyone,
Nice to meet you all, I regularly browse the forums but decided to create an account because I have a question that I just can’t wrap my head around.
Yesterday I removed the elbow from my intake. And I found this white residue almost like a powder sitting on the bottom just before the throttle body. I attached some pictures for your reference.
I kinda fear that this this stuff also went in the engine and I have no idea what it is.


Any ideas what this could be?

 

Does your set-up still have the oil pan breather recirculated to the front turbo. Blowby could be getting cooked in a hot turbo. This might happen if you overfill the oil above the markings.

 

blow by wont become a powder. i would say clean that out, drive it for a few weeks and see if it comes back. that could be from something long before your time and it just wasnt cleaned out.

 

Maybe a previous owner used auxiliary injection, but used tap water instead of distilled water. Or windshield washer fluid as there is maybe a hint of blue in the pictures. Minerals in tap or the detergent in washer fluid can fall out of solution and look like that over time.
Was there any evidence of nozzle placement on the intake elbow or farther up on the intake tract?

I’d clean it off and as suggested above, check it again after a few thousand kilometers/miles. I think the rotary is pretty tolerant, I doubt with that little amount it hurt anything.

I also see evidence of red RTV around the throttlebody ‘O’ ring…like they may have been fighting a leak. Last I looked a new ‘O’ ring wasn’t terribly expensive.

 

Now that you mention it ,maybe the coolant that runs through the throttle body is seeping out somehow.

 

^Really not likely.

Also there’s an air-bleed screw right under the residue in the pic. After cleaning it out, it might be worthwhile to use a bit of penetrating oil and make sure that screw is free and not stuck. Just make a note of it’s original position before giving it one or two turns in each direction before turning it back. You might even see an improved idle.

 

Thanks for the responses guys.

I finished converting to a single turbo set-up a couple of weeks ago, so I am not sure about the oil pan breather recirculation(?) but I am guessing that's gone by removing the stock twins.

Just ordered a new 'O' ring as I think it's indeed a good call to replace that.
For the rest, I indeed cleaned it out and I will check in a while if it has returned.

She wouldn't start that's why I got worried. But unflooded her this morning and took her for a spin. She runs fine.
If it returns I will let you know.