Well i got 2 new knock sensors in and realized how much carbon was built up in the intake, OMG i had chunks comin out. I was gona clean it all out but just decided to get what i could with a rag and clean the throttle body good when it was off. So i got everything back togethar and it ran fine so i got some seafoam and did the vaccuum line trick with a straw and a cup, let it sit for 45 mins or so then had a helluva smoke show. Wow....i duno if it was the seafoam or what but i can tell a huuge difference in the idle, throttle response, and throughout the rpm's. it idles like it did when it had 30k miles on it. This thread is for anybody thinking about using seafoam. I highly recommend it!!

 

Thank GM for the wonderful PCV system on these trucks and the crap they send into the intake manifold. Trust me. It will pile back up in there. Catch cans on the PCV line are the best way to avoid that problem.

 

i thought the egr was what mostly caused all the carbon?

 

Nah, it's the oil that gets sucked through the PCV system mostly in the case of the GENIII's, combined with normal carbon buildup from incomplete combustion/unburnt fuel, etc. The EGR is a contributor also, just not the biggest offender. As silver mentioned, a catch can in line with the pcv system will help tremendously...I drain over a tablespoon of oil from mine about every 1k. If you do a search on "catch can", you'll find a wealth of info.

 

thanks alot i wish i woulda known this when i had the intake off but i guess a catch can cant be too bad to install.

 

It's a piece of cake...goes in-line from the PCV valve to the intake. I have one made by AMW, but they're quite pricey now ($90 when I bought mine, I think they're almost double that now...there's a link to their website at LS1Tech.com)

Here's a pic of mine:

 

Mustangs must have the same problems, because on stangnet.com there was a writup about how to make your own PCV catch can for like 20 bucks. Ill try to find it later.

 

There's a write-up around here about a home-made catch can also, using an oil/water separator (for an air compressor), some brass fittings, etc. It came out to less than $20 also. I made one prior to my AMW, but it filled up quickly and stopped functioning after about 1k. I'm sure that with a bigger separator, different filter, etc., it can still be done at home fairly cheaply. Type "catch can", and/or "home made catch can" into the search bar and there should be a ton of info for sure