angrypengu

As most of you are aware, one of the challenges we all face with gasoline direct injection is carbon buildup. I was very surprised today to learn about the additives used in the CRC Intake Valve cleaning solution. I am thoroughly impressed as it has the PEA additive that I so love which I found with the Redline SI2 fuel additive (the idea is the PEA additive survives combustion, joins the blowby gas through the PCV system which then flows past the intake valve. The concept is that whatever additive that survives that entire process ends up helping to keep carbon deposits at bay. The other thing that I stick with religiously is Shell Premium which also has the PEA additive.)

I got excited today because the idea of spraying something directly on the backside of the intake valve that has PEA is what CRC has developed. In my last few Audis, I used to just take the Redline SI2 cleaner and do the same, which isn't ideal due to hydrolocking concerns, of course.

All this to state that I now struggle with where to use that CRC product. I'd like to confirm my understanding here of the EA839 engine. Here is a picture taken from the self study guide. My questions are below.




The CRC product has to be applied into the intake system of any engine, and pass any sensors (such as MAF). Ideally one would spray it right before the throttle body, but I have no idea where it is on the EA839.

That said, the red box and the blue box are what I added to the photo. I would presume the CRC liquid is injected to either one of these positions. red box = past the air filter, and in the blue box, it would feed to both intake manifolds on either side of the V6.

I want to ensure my understanding here is correct. In the left box, the cold air that passes the air filter is fed directly to the turbo? I don't know enough about how forced injection works, but typically it's air box -> throttle body -> intake of engine. (My logical guess: Am I right in understanding that fresh air actually goes directly to the intake side of the turbo which then gets forced into the intake manifold, past the intake valves and into the cylinder?) This photo also makes it seem like air goes from the intake box to the turbo, and is mixed with the hot air leaving the engine -> intercooler -> and into the blue box.

Can someone please help me with how this works on this engine with respect to the path of the cold fresh air after it passes the filter? Is my logical guess correct?

Thanks!

angrypengu

It would appear that after some research, the way this works is that in the red/left box, fresh air gets fed through directly to the cold side of the turbo, and that air is mixed with the hot exhaust gasses from the engine, then it goes through the intercooler, then into the right/blue box, then it goes past both intake manifolds and the into the cylinder.

Then in that case the best place to put in the CRC intake cleaner is in the blue box area, or on the "Exit/cold side" past the intercooler.

I've read a Youtube comment that there's no MAF on this engine? That would surprise me. Does anyone know?

HCGxKaLiBeR

I was doing CRC intake cleaning and came across this post.

So to OP... The correct flow is: Air gets suck in to the air intake -> goes through the turbo -> turbo compresses the air thus it gets hot (air gets hot when compressed, hot air is not as dense as cold air) -> therefore air then travels through the intercooler gets cool down-> then goes through the throttle body and splits to the intake manifolds.
I'm not sure if EA839 has MAF sensor or not but I think the sensor G71 may not like the cleaning product...

After some research. I think I will hold off doing my S4 B9 cleanup. OP, since this is a 5 year old post... if you have already done so, let me know how it goes.