I've been having some idle issues the past month or so. Did all the usual checks: boost leak, vacuum lines, IAC... all that good stuff. So I decided to pull off the throttle body and see if maybe there was some build up in it that was causing an issue. This is what I found:



On top of that, there is a crap ton of soot on the IM side of the TB and inside the IM itself:





Also, the BISS screw is chewed all to hell and looks to be screwed all the way in:





So at this point, I'm thinking I might need a new TB... But the bigger question is what is the deal with all the carbon deposits? I know it runs rich, but holy crap...

Anyway, just wanted to share my discovery and see what everyone's opinions are on it.

 

Also, the brownish crud on the UICP side there has a sulfur type smell to it when scraped off. I'm not sure what the hell it is...

 

if you are still using your stock valve cover re-circulation the black gunk is normal.... typically your TB will become sticky in colder weather and you'll need to clean it... mine looked like that at like 45-50k miles... the other side.... well that's not normal.. was the rust or dirt I couldn't tell?

 

looks like ur evo got sick and threw up. never seen that before (the yellow stuff). but thats a lot of crap. u might want to check ur turbo, ic and piping.

 

The stuff has a consistency of dry clay or something... and smells mildly of rotten egg. Nasty for sure.

 

is the car smoking? that might be coolant and oil mixed with carbon. MIGHT BE! turbo seal went out? dont quote me,

edit, some say its just condensation? ?

http://www.srtforums.com/forums/f24/...-stuff-490540/

 

It will only smoke if it dies and then I start it back up... It seems like it's not getting enough air and chokes out, then when I start it again it's got a bunch of unburnt fuel and runs kinda rough and smokes a bit...

 

Don't mess with the black stuff. You can take a rag and wipe off anything that's loose, but don't go scraping or using solvents to get the "soot" off. That's how its supposed to look...I know, I wouldn't believe me either cus it looks so gross, but here...

https://www.evolutionm.net/forums/ev...e-sealing.html

As for the light brown crap, not sure what that is. If it were coolant/oil it would prob be a film as opposed to what you have, which looks like a dried paste. Is it hardened on there or does it wipe off? Is your upper IC pipe lined with it too? Are you the original owner? Clean it off and see if it comes back lol...

 

What does the inside of your intake/air filter look like, and how does your MAF look?

 

I only wiped off the loose black stuff. There's 4 spots on the IM side of the butterfly valve edges that have a harder substance on them. I'm assuming its the sealant:



The brown stuff is hardened and is like dry toothpaste, for lack of a better description. I didn't see any in the upper IC pipe. I'm not the original owner, I actually just got the car less than two months ago. I knew it had a hard life, but am willing to do the work needed to get it back into good shape. This however, is a new one for me. Never seen anything like it before.

 

probably somebody tried to make it easy for the hose to connect to the throttle body and used just enough "grease" to make that mess.

 

The MAF was cleaned and the filter changed when I got the car, in January. The MAF had some slight soot and oily film, but nothing major.

 

Have you tried Sea foam to clean it.

I would try it and then inspect it all again.

 

that looks like somthing that would come out of a catch can if its recirced back to the intake. oil and condensation look exactly like that. if you have a catch can look in it to see if its the same color.

 

Added to my "to do" list! It needs it bad...