Normally I would say there is wear in the bushings the throttle blade rotates on and the throttle body needs to be rebuilt, but there's two problems with that. First, this shows up due to very high mileage, as in over 300,000 miles. Yours does not have that much wear yet. The second problem is your car most likely uses the "throttle-by-wire" system that put Toyota in the news a few years ago. I've never autopsied one of those assemblies to see what's in them, but I do know they use a really strong motor to turn the throttle blade. I would start by looking for something that could have occurred on the assembly line, like a mis-positioned gasket, a cracked housing, loose mounting bolts, and things like that.
I know this can be hard to tell, but if it looks like there's something that could be a common or recurring problem on many cars, there may be a recall or service bulletin. Dealers will take care of recalls at no charge to you. Those are issued for safety and emissions concerns, and some manufacturers issue them for customer satisfaction concerns.
Service bulletins are issued to help mechanics find the causes of elusive, but common problems. They are only meant to save time. You have to pay for the repairs if the car is out-of-warranty. The bulletin will specify part numbers and repair procedures. I would leave anything related to throttle-by-wire systems to the dealer. Most independent mechanics don't want to work on them because anyone who touches it could become party to any future lawsuit, and it's only a matter of time before another malfunctioning computer sends a driver on a wild ride. That will probably change in the future when the independent shops learn more about these systems. There have been many instances where mechanics were baffled by something new, like Chrysler's "alternator", "Lean Burn" Engine Computer, anti-lock brakes, and air bags, and GM's "HEI" ignition systems, so they refused to work on them. Now those are very common and simple systems. This is the first one though where making a mistake can kill someone, hence the reluctance to work on them. This is also why I don't recommend you work on it unless you see something obvious and simple.
Saturday, August 20th, 2016 AT 11:33 AM