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[Solved] Is this normal after cleaning the throttle body?


Topic starter

I have a 1998 Toyota tacoma 2.4l, automatic, 2 wheel drive, with 183,920 miles on it. I recently cleaned out the throttle and boy oh boy was it dirty as hell! Surely it hasn't been cleaned in ages. Once I was done I put everything back together the way it was before I took it apart to access the throttle body. I tripled checked everything to make sure everything was in order. I turned on the truck and the engine now makes a really loud humming sound, it was never this loud before. I also triple checked for any air leaks around the throttle body and in the air intake assembly,  didn't find none. The truck drives very smoothly now though, and doesn't vibrate alot like it used to during idling, but it consumes more gas now, still makes that loud humming sound, and shakes just a little bit when I turn it off. Is this normal after cleaning the throttle or did i miss something or do something wrong??

2 Answers

I would say it is normal.

When your throttle body is dirty, you can't get enough air to keep the air/fuel ratio stoich, which is why you had vibrating and general rough running conditions. 

Now that it is clean, you are sucking in more air, which means a smoother engine and likely a bit more fuel is needed to keep things running as intended.

It's a 25 year old truck with almost 200k. It sounds like it is in good shape to me.

Thank you!! @Mod_Man I was a bit concerned about my truck. Thanks for your answer.

You're welcome! I don't think you have anything to worry about. Happy motoring.


It's perfectly normal for your engine to act funny after you clean out the throttle, especially if it was filthy. I did that to my 1999 Ford Ranger last summer, it didn't look like it was touched in 21 years. When I was finished, my truck wouldn't start when I cranked it over 3 times, then it caught on the 4th time and it ran like absolute crap. The check engine light came on, lol. I let it run for 10 minutes and the shaking, rough idle, and some idle hunting gradually went away as the computer relearned how to idle. I probably traumatized it. Haha.   

I cleaned the throttle body on my 26-y-o Lexus. Now the engine does not start. I wish I could traumatize it a little instead of killing it outright...

Did you clean the MAF sensor with MAF cleaner and let it dry before plugging it back in? There's no real reason it shouldn't start if you did all of that. It may take a few cranks, but it ahould start.

I cleaned the MAF sensor with an electronics cleaner. They are identical, as people say. Probably sprayed too much of a throttle cleaner beyond the throttle valve. Or there is something unrelated at all.