carbon build up in tube from intercooler to TB
 

How much carbon build up is normal for the intercooler to throttle body tube? I am installing new belts PITA!! and took the tube off. There is a pretty substantial amount of carbon build up in there and I am not sure if that is a sign of a problem. There was also some oil in the tube, which I understand is normal. Any help?? Thanks.

I don't think there should really be a carbon build up in those pipes. Oil usually appears from being spit through the turbos for so long. Its normal just as long as there's not too much. If there is a large amount of oil in there, clean it out and have your turbos checked. You could have an oil leak or broken gasket in them.

It looks pretty extensive. I will try to post a pic when I get home later today, but when I pulled the pipe off there was like 3-4mm build up on each side right where the pipes meet eachother. I guess I should wait before I buy all my aftermarket parts until I see if I need to replace the turbos. That would suck!!

some oil is normal. check the primary turbo, if you see oil dripping from the air outlet heading up then it could be a leak or blow by. if the turbos were rebuilt there will be some blow by more than when they were new. if the turbos are not leaking you should try an oil catch can if you have an extra 100$. if you put your finger inside the elbow and your finger has liquid oil dripping that is a not a good thing.

Isn't Carbon Build up a result of combustion? umm last time I checked fire in the intercooler and IC pipes is not something you want. If it really is carbon build up not just crap that got in unfiltered then I think that something is really wrong.