Cleaning the throttle body on a VY2 SS

[Surfwagon]

Its oil mist from blow back from the crankcase and yes it can affect engine performance and especially the ron rating of your fuel if there is too much oil in the intake.
The pcv can handle so much but any excess feeds back up the crankcase air inlet itno the TB and into the manifold.
This is why people fit oil catchcans, I have the Elite version on my LS2 and when I fitted it (about 3years back) the manifold was covered in drippy oil internally.
I recently fitted a new manifold and the old lS2 manifold only had a minor shine of oil so the catchcan is doing its job.
I get about 10-15mm deep of oil in the catchcan at each 5k oil change.
PCV Oil Catch Can Pontiac GTO 5.7L

 

[Cheap6]

Doesn't it defeat the purpose of a air filter if you are going to remove the intake system along with the air filter to spray cleaner into the throttle body?

The air cleaner stops solid particles from being drawn through the engine with the air (the engine consumes a lot of air - even a very small proportion of dust in the air can be significant). While it's true that running the engine with the air cleaner disconnected will risk drawing some particles into the engine, unless your doing it in a coal mine, it's not going to be happening for long enough to make any real difference.

Would this still be applicable if you have fly-by-wire throttle?

Well, there's no IAC valve but other than that, yes.

Couple of questions. How does all that black oily crap get into the throttle body to start with and how does it effect the likes of your idle and engine performance??

The build up of the residue affects the airflow past the throttle plate at very small throttle openings i.e. idle. It can also cause the throttle plate or IAC valve to stick and the PCM to lose accurate control of the idle speed.

 

[NU13]

So i brought some CRC throt-l-body cleaner. Was reasonably easy in the end to clean the throttle body. What i did in the end was just loosen the screw down rings on the the intake pipe and move it to the top of the throttle body. Opened the butter fly value sprayed a heap of cleaner into the throttle body, replaced the intake pipe and started the engine. Repeated this about 4 times. Very black looking fluid coming out and a heap of smoky crap from the exhaust. I assume that it will take a while for the PCM to change it's idle habits.
Also cleaned the wifes throttle body in her 1.3 Suzuki Swift.