Ok... dont beat on me too much here for all the things I didnt do and should have done. But... I have a 2014 GMC Sierra at 80k and I have NEVER done anything to the intake valves, no CRC, no seafoam, no BG GDI, nothing. I have done full synthetic oil changes at appropriate times, techron fuel cleaner here and there, new air filter, MAF and throttle body cleanings, etc.... but not the intakes. Anyhow, truck has been SLIGHTLY slower, using a little more oil, SLIGHTLY more vibration at idle, and last few weeks I have gotten a "cold start rough idle" code, and a random misfire code, on/off (it happened twice). Mechanic friend down the street who I trust and have used forever found nothing specific but recommended I had the valves decarbonized.
So... the question is... AT THIS LATE STAGE OF THE GAME... 80K MILES... what would you do? I fear the CRC or Seafoam thing would create more problems with the large deposits coming off. I have called a few places looking for the BG GDI cleaning, but all the places BG lists only offer a fuel system cleaning and NOT the back of the intake valves directly. I called the dealership who of course would do it manually, but they want $600. Does anyone have a suggestion for how to do this? I feel this is above the DIY job for me. In the future, sure, I'll do a seafoam or crc in the intake just prior to oil changes and maybe do a catch can as well, but AT THIS POINT, what would you do? Thanks, Chris