Originally Posted By: mechtech2
Evidence? Years of seeing so many that are filthy in the shop. The cleanest ones were far away from the residue/pooling in the manifold.
Cleaning a TB is not a 'malfunctioning part'.
If your TB is staying clean, be happy - you are lucky and this is not common.
Staying clean? No, but after I cleaned it for the first time around 120K miles, I was surprised at the lack of buildup it had, and how easy it was to remove what was on there. The TB had never been touched prior to that. There was also no discernible difference in performance after the cleaning, so it obviously wasn't a lot of buildup.
If the IAC has to compensate for a TB that allows too much air to pass at idle because the coating has been stripped off, to me that means the TB is malfunctioning.
Do you tell your customers you are disregarding manufacturer warnings to not remove the coating? Yeah, I know, they probably don't care. I wouldn't want a shop to just disregard a manufacturer warning though and strip off a coating that was put there for a reason. TB cleaner doesn't cost that much, may as well do it right.