Throttle body cleaning tips?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by cyberpriusII, Dec 27, 2014.

  1. sosarahsays

    sosarahsays Member

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    Thanks for the responses -- seems like the maybe recommended it as a "recommended" service to try and get a bit more money out of my wallet after all!

    ... I do think this sounds like something I can eventually try myself, though. I get nervous about breaking stuff, too, Kris, but I love being able to do my own stuff and be knowledgeable about my car. Plus, I think it makes me less likely to get scammed at the dealer! :)
     
  2. Yakoma

    Yakoma Active Member

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    Read up on the MAF...it's definitely one of those things you need to be careful with. It's relatively delicate and, if you damage it, you will damage the performance of your engine. But, if you are careful, it's also easy to clean and not damage it. The way I look at it is that it's also easy for some numbskull at the stealership to damage, so I trust myself to do it before I would trust them to do it.
     
  3. greenbubba

    greenbubba Junior Member

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    Thanks Mr Wong et al for the confidence to clean mine. Other than the paper towels this short and sweet video also made it a breeze. I liked having the filter housing off - made it easier to get to everything.
     
  4. edthefox5

    edthefox5 Senior Member

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    Really bad.

    You don't have to take that back bracket off with the 2 bolts the air cleaner assy just hooks onto that. Don't use a screwdriver and a paper towel. Use a cut up piece of soft cloth I like strips of old t shirts. Soak the cloth and shove it down the bore and scrub away. Soak the cloth real good while in the hole with choke cleaner. Pull it out and discard & repeat with fresh cloth. Scrub front & back of butterfly plate.

    After thorough cleaning Inspect the bore & butterfly closely with flashlight especially the mating edge area of the butterfly to bore. This butterfly edge gets corroded & rusted and can get stuck in the bore leaving you stranded. See how hard it is to open the butterfly by hand
    and if it freely opens up.

    And the video missed the most important part flushing out the PCV input tube on the tb. Disconnect the big hose on the back of the tb and while cloth in bore flush out that input tube hole. Thats where all the oily gunk gets into the tb via the crankcase PCV. That hole is easily clogged killing PCV.

    Lubricate the throttle return spring.

    Don't forget to tighten the bore clamp under the housing after housing re-installation.

    When I go through the trouble of a tb clean on a G2 since the housing is off I will take out the VVT oil filter and check it. Its behind a hex key bolt head under intake runner #1. First time you take it out it requires a breaker bar to get it off. Use a high quality socket hex key not a piece of junk from Harbor Freight. I have owned the car since new and have kept up with oil changes but if the car is used and new to you its worth a peek. Especially if its seen dealer oil change its whole life. The cars performance will suffer if that tiny oil filter is clogged.
     
  5. Stevewoods

    Stevewoods Senior Member

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    Heck, I was looking around for a video on TB cleaning and found a good one this morning.

    Then, I come on here to post it, only to find that Greenbubba already posted it a couple of posts above me!

    Anyway, four things that the video does not cover, one is that after you pull the airbox, go ahead and clean the MAF, odds are if the TB needs cleaning the MAF really needs cleaning. I took the MAF out of the airbox before cleaning, but I seriously don't know why you would need to. It is much easier to take MAF screws out if the airbox is out of the car.

    Number two: If you take out the two 10mm bolts holding the relay box that is just above and slightly obstructing the airbox bolts, and then swing the box out of the way, it is easier to access the airbox bolts, etal.

    Number Three, as long as you have the snorkel disconnected from the airbox, might be a good time to clean it. My wetvac hose end slips into the airbox end of the snorkel nice and tight. Turn it on and you will vacuum up any gunk that might be stuck in the snorkel.

    Finally, for the 10mm clamp under the airbox that holds the airbox to the bore, A normal 10 mm socket had no access because the bolt is set back so far.

    My short socket extensions were too long and I was blocked by the coolant recovery tank. I poked around and finally found a deep well 10mm socket that once connected to the wrench, worked perfectly, indeed, I used it on all the bolts.
     
    #25 Stevewoods, Oct 8, 2015
    Last edited: Oct 8, 2015
  6. edthefox5

    edthefox5 Senior Member

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    The maf rarely gets very dirty. Its above the tb and is protected by the air cleaner. A novice can do more harm than good going after it. Just leave it in the housing and undo the wire clip and set the box aside. You'll know the maf is whacked out as it will throw a dtc. If you must clean it just buy a can of MAF cleaner and give it a spray or 2.

    And you don't have to take all those brackets off. The airbox is just hinged to all that.

    The throat clamp just requires a short extension.
     
  7. Stevewoods

    Stevewoods Senior Member

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    Ed, I saw you mentioned the airbox and hinges before, but you are just talking about the top cover of the box, right? Not the bottom?

    Because I can see no way to remove the entire box, top and bottom without taking out the bolts, etc. I could be wrong. So, if I am missing something I apologize.

    I do know that some people say to just remove the top of the box and try to work around the MAF and just use a towel taped to a screwdriver to clean the TB, but as you said the MAF can be damaged and I did not want to risk that by trying to poke around the side of it.

    If I remove the entire box, not just the top I can actually hold the cleaning rag soaked in TB cleaner with my hands and get down there and give a good scrub by hand and not have to go through all the taping of the screwdriver, etc.

    Conditions vary, but just looking at the MAF while it was screwed into the box, it really looked clean. However, since I had the entire box out, and it was easy to unscrew the MAF from the box, I did just that. When I actually had it out in the light of day, it actually was dirtier than it looked. It was by no means filthy, but the wires and bulb were coated pretty well...of course, can't really see into the other part of it.

    Anyway, this is all a learning process for me. Much different than my first vehicle -- a 1966 Yamaha 250 Big Bear Scrambler -- which I eventually slammed into a block wall. Wall and bike mostly survived. A few days of hospitalization and I did also.
     
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