Rep Power: 0

Hi i have a 99 honda civic ex

Car idles up and down when in Park what will cause it i took it to a garage and he had it two months he said i needed a throttle body so i paid 200 had him get one put it on, he said the sensor on it was bad i needed to buy a new throttle body for it will that make it idle up and down?

 
Rep Power: 0

i have a 99 honda civic ex i bought a throttle body and had it put on what the garage said it needed so they got one put it own then said it was bad i needed another one said its the senor bad on it. when i put it in park it idols up and down?

any ideas he said he has took the hole motor apart but what is causing that was the sensor

 
Rep Power: 518

There are several things that could cause the idle to surge up and down repeatedly.

If it needs an IAC valve (attached to the throttle body if the car has automatic trans) that can be purchased by itself, or you could look for a complete throttle body at a recycle yard.

If the IAC valve is simply stuck, sometimes it can be cleaned.

If there's an electrical or wiring problem causing the IAC valve to not operate, replacing the valve isn't going to change anything (obviously).

Sometimes something as simple as low radiator level can cause the issue too.


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From your description of the situation, it would seem you are at the mercy of a mechanic or shop that sounds either shady, lazy, or less than qualified to be working on your car.

It should not take two months to figure it out if one knows what they are doing. More like an hour or less.


If you paid someone $XXX.xx to obtain and install some part, and they obtained and installed a broken/bad/defective part, IMO they are obligated to supply and install a good unbroken and working part at no additional expense to yourself. (exchange bad part for a good part wherever they got it from)

 
Rep Power: 210

Never use this mechanic again. Two months? Lol

 
Rep Power: 210

Sounds like he is referring to the TPS (throttle body position sensor).. it, along with the throttle body rarely fail. As Ezone mentioned could be several suspects but with surging idle cleaning the IAVC (idle air control valve) and the TB (throttle body) with throttle body cleaner spray is the first place to start. Any CEL's (check engine light)?

I don't know what your level of knowledge is as far as auto care acronyms and auto repair in general so please forgive me if you already know them.