I just switched out my 9.8 hotside for a new 10.5. I pulled my 9.8 hotside off and its all white after the turbine. Anyone know what causes this? Is it normal? Should it be something to worry about?



The downpipe is carbon black along with the rest of the exaust. Exaust manifold is black too. The only part that is white is the hotside after going through the turbine/wastegate.

 

have u ran leaded gas before?

 

I sense race gas.

 

Nope, I've never ran race gas, But i've ran xylene as octane booster a few times.

 

that's just a higher octane level alcohol or race gas or something in that line..

same thing.

unless you're running lean?... i'm so off tonight.

 

that hotside looks normal. you have to understand that all of your gasses are spent right there and they will get reeeeeeeeelllllly hot at times. now, if all of the housing were white-you can see alot of carbon build up on the sides-then you are running realllllly lean or reeeeellly rich. but overall it looks normal.

 

I don't have a wideband or EGT gauge to verify if I'm running lean. I'm running the Works P2 reflash (91 octane) which should be pretty safe. Why would it just show up right after the turbo, y not the whole exaust system?

Oh yea, and the O2 sensor has some white on it too.

 

Alright, thanks man. I've just never seen something that white before in an exaust system.

 

Wow, thats really white.

 

i think that should be black, not white.

 

The turbine housing off my 1g DSM looked like that. I never figured out what caused it though. I did run lots of leaded race gas through it. The grey coating at the exhaust tip would usually go away after putting unleaded gas back in, but the whiteness always stayed in the turbine housing. I also ran octane boosters as well.

Regardless, I never had any problems with the turbo after over 100k miles.

 

Okay, I just went into my garage to look at my 9.8 hotside and it has traces of that same whiteness in it as well. I've run nothing but pump gas on my evo, so my guess is that it's caused by the extreme heat of the turbo.

 

yeh, i guess the heat could cause that...

 

I highly reccommend that you refrain from using octane boost supplements. They have all kind of BS in them that is not good for your engine. It also cause your fuel filter to go pretty quick too. When I first got my evo and didn't know any better I used to put that crap in all the time thinking I was gaining power. I may have picked up a 1/2 of horsepower, but was doing more damage than good. When I swapped out my fuel pump with a Walboro the mechanic was like you used a lot of octane boost at one point didn't you? I was like yes why? He said look at your fuel filter. It looked like crap and was discolored. Good luck and I dont think you have a serious problem.

Matt

 

Thanks for the input guys, I was worried that is was a symptom of engine damage or something. I did use xylene probably every other tank last summer but haven't used it since, It gets expensive. I did feel decent gains from it though.

Is that screen type baggy thing on the fuel pump the fuel filter? Should i change it out as a precaution? Would xylene casue it to deteriorate?