Throttle Body Cleaning

[HowAboutThis]

Should I clean the throttle body on my 17 Corolla? I've got around 125k miles, always had a slightly rough idle after warming up (popping into neutral or park smooths it out so I've always concluded it's transmission related when in drive and stopped), but the dealer mentions it as preventative at times.

Looks easy to do. Pop the intake hoses, use throttle body cleaner on a rag, etc.

I do read and see conflicting advice on gently opening the butterfly to clean/wipe it and the edge around it. I've read some places say never move it by hand. But other seemingly reputable videos and sites say to gently open it and wipe it down.

Advice? Anyone do this? I checked it at about 75k and it looked clean enough so figured it's one of those "money makers" at the dealer. 10-15 minutes of work for a half hour of labor.

Any relearns or anything? Or as simple as remove hoses, gently open and wipe butterfly, attach hoses?

Thanks!

 

[iahawk]

cleaned my kids '06 Vibe (drive by wire...maybe great grandfather to your TB?) just as you described...TB cleaner and a soft microfiber, disconnected from all hoses and gently opened and cleaned. Looked like new when done.

 

[Kira]

Turn the car ON.
Place a weight on the accelerator to open the throttle plate.
Go in and clean it.
Get back to us on this thread and tell us how dirty it was and what you did.
It should prove interesting.

Have fun! (seriously)

 

[tig1]

I take my throttle bodies off to clean. It's easy on my two Ford Fusions, and clean them every 50K.

 

[Capt W]

I take my throttle bodies off to clean. It's easy on my two Ford Fusions, and clean them every 50K.

Absolutely! Pick up the required gasket(s) and pop it off. Not the least bit difficult on most cars, and a lot more thorough.

 

[4wd]

The cheap TB cleaner will bog down a running engine - but CRC intake deposit cleaner will not be as drastic at that - and cleans very well … Ain’t cheap … I use a Qtip if needed

 

[HowAboutThis]

Turn the car ON.
Place a weight on the accelerator to open the throttle plate.
Go in and clean it.
Get back to us on this thread and tell us how dirty it was and what you did.
It should prove interesting.

Have fun! (seriously)

See, this is where I've read different things from YouTube people that seem reputable, websites of throttle body cleaner company instructions, supposed dealership articles. Not all Toyota.

Some say to do it with car off and MAKE SURE it's not ON. Some say what you say. Some say you must disconnect the battery unless you do the relearn procedure. Etc.

And I feel like, by the end of this thread, all of those will be mentioned in here, too

@Kira you're a frequent commenter but I can't remember your story. How certain are you on turning the car ON? Are you a technician somewhere or shadetree like me?

I really just don't want something easy and basically free ($5 for cleaner) to end up costing $400 after the dealer has to run an OEM scanner and do something I could've avoided

 

[Legs4Arms]

Should I clean the throttle body on my 17 Corolla? I've got around 125k miles, always had a slightly rough idle after warming up (popping into neutral or park smooths it out so I've always concluded it's transmission related when in drive and stopped), but the dealer mentions it as preventative at times.

Looks easy to do. Pop the intake hoses, use throttle body cleaner on a rag, etc.

I do read and see conflicting advice on gently opening the butterfly to clean/wipe it and the edge around it. I've read some places say never move it by hand. But other seemingly reputable videos and sites say to gently open it and wipe it down.

Advice? Anyone do this? I checked it at about 75k and it looked clean enough so figured it's one of those "money makers" at the dealer. 10-15 minutes of work for a half hour of labor.

Any relearns or anything? Or as simple as remove hoses, gently open and wipe butterfly, attach hoses?

Thanks!

This totally sounds like an IACV issue to me. The TB is easy to clean so have at it but I suspect the issue will persist.
If the car runs and pulls well in every other scenario save for idling at a long traffic light for instance, the IACV is surely the culprit.

 

[HowAboutThis]

This totally sounds like an IACV issue to me. The TB is easy to clean so have at it but I suspect the issue will persist.
If the car runs and pulls well in every other scenario save for idling at a long traffic light for instance, the IACV is surely the culprit.

If that's the case, it's been bad since brand new If you Google "Corolla low idle at stop" it seems to be common and the way Corollas idle, if you believe the Internet. Pop in neutral and it's great. Some say it's the TC, some say it's Toyota computer running as lean as possible for fuel economy and that after a longer highway drive it's more common for the computer to do this, etc.

I was just happy to know others have the same issue since new

 

[Kira]

@Kira you're a frequent commenter but I can't remember your story. How certain are you on turning the car ON? Are you a technician somewhere or shadetree like me?

I'm a shade tree.
My angle is that I've owned 3 vintages of the Volvo 5-cylinder, non-turbo engine, the B5244S, spanning 20 years.
Open the plate as described and clean things without moving it.
The one repeated caveat is to not muscle the thing....so I never have and never had a problem.
I have no idea if that advice is based in fact or common prudence.

Use wire hanger wire and cloth for reach.
Be careful of lint/threads.

Legs4Arms' post just came through:
The IAC Valve in my Ranger 4.0l has a test done with the engine warm and idling.
You unplug the IAC Valve and the engine will stumble and even die. That's normal.
See if there's a simple procedure like that for your Corolla.

Also, for the Rangers with bad IAC Valves, owners are urged to buy Motorcraft or Hitachi (OEM) IAC Valves as the signal sent to them by the ECU matches the motor in the valve. Queer aftermarket stuff doesn't work.
Again, see if such a caveat pertains to your vehicle.

 

[Kestas]

I use gasoline and a toothbrush. Some deposits can be stubborn for a rag.

 

[Legs4Arms]

If that's the case, it's been bad since brand new If you Google "Corolla low idle at stop" it seems to be common and the way Corollas idle, if you believe the Internet. Pop in neutral and it's great. Some say it's the TC, some say it's Toyota computer running as lean as possible for fuel economy and that after a longer highway drive it's more common for the computer to do this, etc.

I was just happy to know others have the same issue since new

The reason it smoothes out and idles higher in "N" is because the engine is free spinning and is no longer fighting the converter's stall load. In "P" or "N" it meters bypass air to hit the target idle speed, in "D" it works harder because the converter is loading the engine. If the valve is weak or sticky, this is where the issue will show it's teeth. The longer it idles in "D" the worse the idle will get.

 

[SatinSilver]

Check out TCCN on YouTube for specifics on your model from him as a Toyota tech. Although many good suggestions already mentioned on here.

 

[HowAboutThis]

Check out TCCN on YouTube for specifics on your model from him as a Toyota tech. Although many good suggestions already mentioned on here.

That's what I'm commonly seeing on YouTube. The chemical cleaner company websites often say to actually spray it inside. Everyone else seems to say NOT to do that and to ONLY wet a rag and wipe.

 

[Legs4Arms]

I used this, sprayed liberally on a microfiber shop towel.
Wipe the front of the throttle plate, plate edges, bore walls, and the lip where the plate rests.

Final pass with a gloved hand in a coffee filter for a lint free finish. Good luck

 

[iahawk]

That's what I'm commonly seeing on YouTube. The chemical cleaner company websites often say to actually spray it inside. Everyone else seems to say NOT to do that and to ONLY wet a rag and wipe.

granted, I've only cleaned the TB on 2 different cars...but the CRC TB cleaner sprayed on a clean microfiber easily dissolved every last bit of stuff in there. No need to scrub with a brush and no need to spray the cleaner in the TB. Always start with the gentlest option and work your way up if necessary.

 

[SatinSilver]

That's what I'm commonly seeing on YouTube. The chemical cleaner company websites often say to actually spray it inside. Everyone else seems to say NOT to do that and to ONLY wet a rag and wipe.

Just remembered a few months ago I bought the 2 pack of CRC throttle body cleaner and MAF cleaner at Walmart. My point is you may want to clean the MAF sensor. So easy to do and you may notice an improvement in performance.

 

[martinq]

I used this, sprayed liberally on a microfiber shop towel.
Wipe the front of the throttle plate, plate edges, bore walls, and the lip where the plate rests.

Final pass with a gloved hand in a coffee filter for a lint free finish. Good luck

Final pass w a coffee filter is a good tip. They're an easy to find and cost effective lint-free wipe.

 

[researcher]

That's what I'm commonly seeing on YouTube. The chemical cleaner company websites often say to actually spray it inside. Everyone else seems to say NOT to do that and to ONLY wet a rag and wipe.

ok since it's a Toyota, I'll tell you how I always clean the Camry engine 2.4L that's in my Scion tC. I leave the battery connected, turn the car to the ON position but DO NOT START it.. Have someone push the gas pedal down so the throttle plate opens, clean both sides.. No issue.

The reason you do not want to spray throttle body cleaner into the throat is because on the other side might be a PLASTIC (nylon composite) intake manifold. Throttle body cleaner has acetone in it, it will hurt the plastic manifold. That's why I use the foam cleaning swabs, apply the cleaner and gently clean things. The other cleaner you could use is the MAF sensor cleaner, it's safe for all plastics. I still like using the swabs, helps to remove the dirt/gunk.

and yep I agree with @Kira, turn on and hit gas pedal to clean both sides. Had to give them a shout out.

The other part, not sure if Toyota is still doing this. On my throttle body, you open up the throttle plate, and on the inner side you'll see a hole, that hole is how the electronic throttle body gets extra air, basically that is the IACV (idle air control valve) hole. Make sure to clean that too.

I've noticed that yes the computer does re-learn after cleaning, since the angles are different once the gunk is gone, no worries, it will adjust. On mine takes about 200miles.

 

[BrendanC]

CRC MAF cleaner is the best stuff i have found at cleaning throttle bodies. it absolutely melts everything. spray it on a rag then wipe the build up away.