Hey guys. After reading this thread from beginning to end, I decided to do the seafoam treatment on my '00 Yukon. The yuke is my daily driver, and has realatively low miles for it's age...just shy of 97K. It has been a flawless truck since I bought it in January of last year. I bought it from a dealership, and they said it was very well maintained. So far, I am thinking the extra $1800 I spent on a 3 year warranty was a waste of money.
I used deep creep to clean out the throttle body first, just to see how much gunk was in there...there was a rather thick layer around the edges of the throttle plate as well as behind it, and some general soot and gunk in front of it.
I wanted to take the thing off completely to give it a really thorough once-over, but got a little scared when I noticed what appeared to be coolant lines running through it. So, I unbolted it and got in behind it as best I could, but there was still alot of gunk around the plate bearings and whatnot that I just couldn't get off. SERIOUS amounts of crud in the air passages (or whatever they are called). That all got put back together without a hitch, so I decided to try the seafoam in the PCV valve and see how much smoke I could get. I let it sit for close to 30 minutes while I cleaned up the engine bay a little bit.
It started rough just like I was expecting, but suprisingly I didn't get as much smoke as I thought I would based on the condition of the throttle body. It smoked pretty heavily for about 4-5 minutes, but after that it was completely gone. I used nearly half the can through the PCV valve, and dumped the other half into the oil per the instructions on the can. I took it out on the highway until the smoke stopped, then stopped by AZ and picked up another can for the fuel system as well as a replacement PCV valve just for the hell of it.
Results?
Not terribly noticeable, but the throttle response seems to be smoother. A little power has been restored, but again, someone who didn't drive my truck on a regular basis like I do probably wouldn't notice. No change in idle, but it's always idled at about 500 RPM very smoothly, so I wasn't expecting it to get much lower. My truck makes a ticking noise for about 5 minutes upon startup when it's cold, so one thing that I am anxious to check on is whether or not the ticking will go away with the combined fuel system and PCV valve treatment. We shall see, I'll update in a day or two. It certainly doesn't appear to have damaged anything or made anything WORSE, thats for sure. There was some improvement, but not a whole lot. I expected a 2000 with 97K miles to be a little more coked up than it was, but I'm not complaining, thats for sure! Next step will be an oil change and possibly spark plugs next week. Wires too, if needed. All in all, I am satisfied with the product, and I'm glad that I used it.
On a side note, is there a guide or a wiki-how for removing the throttle body anywhere, or do I just need to buy a chilton's manual? I'd really like to get the rest of the crud out of it...it's bugging me knowing that I couldn't get all of it out, even though the truck runs fine. I'm anal about crap like that.