How to Fix a Car that Idles Poorly (Rough Idle)

Datum objavljivanja: 3. Ruj 2020.
Does your car idle poorly, have a rough idle, or in general have an idle problem? Learn how to fix a car with high or low idle, and learn how to fix a car that idles up and down by cleaning the idle air control valve. The IAC valve is what keeps the cars idle at around 800rpms. If you turn the ac on and it idles low or your car stalls at lights or in reverse, or your car shakes at idle, this video can also help!
Throttle Body Cleaner:
Pipe Cleaners:
Socket Set:
The OG Idle Air Control Valve Cleaning video (7yrs ago):
→ As an Amazon Associate I earn from qualifying purchases.
→ Become a ChrisFix Subscriber:
→ Instagram: chrisfixit
→ Facebook: chrisfix8
→ Website:
→ My Channel Home Page:
**If the video was helpful, remember to give it a "thumbs up" and consider subscribing.**
Due to factors beyond the control of ChrisFix, I cannot guarantee against improper use or unauthorized modifications of this information. ChrisFix assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. Use this information at your own risk. ChrisFix recommends safe practices when working on vehicles and or with tools seen or implied in this video. Due to factors beyond the control of ChrisFix, no information contained in this video shall create any expressed or implied warranty or guarantee of any particular result. Any injury, damage, or loss that may result from improper use of these tools, equipment, or from the information contained in this video is the sole responsibility of the user and not ChrisFix.


  • I have this issue on my vauxhall zafira 1.7ecoflex I have the part just didn't know if it need reprogramming

  • hi chris... my cars rpm jumped from 300-1400 and finaly we thougth it is a fuel filter so we changed it as soon as we changed it car started end rpm jumped but from 1000-1200 end can not go upper than 4k we got mazda '99 no shop knew what's problem whit it can you please answer could it be iac or throttle body?

  • How did tou you get to where you are now? As in where did you learn so much about cars?

  • Idle at 1500rpm? Now you have a easier hill start.

  • The round dahlia experimentally obey because bicycle peroperativly order following a silent heat. unknown, obtainable relish

  • Read about what JESUS did this is mine blowing. Can you believe this, did you ever hear of this about HIM Romans 10:5/10, c u there! 👌

  • will it kill your power like going up hill if its bad

  • Make video showing how to fix a car that crank long before turns on

  • I’m definitely going to do this, I have a 98 Ford Camry I’m driving right now, and it shakes and idles super rough, and drives really rough. But when it’s in neutral, it’s smooth as silk. Has a P0135 oxygen heater circuit code. I just fixed the P0500 speed sensor with a little ceramic resistor in the speedometer assembly, rather than the actual speed sensor. I’m super proud of myself since I’m an older single woman with no one to help. I’m going to be trying to find what’s up with an O2 heater next, I just happened to find this video while waiting for the autozone to open, before getting the codes ran.

  • My 2002 e46 m54b22 has autogas instaled on it. It runs totally okey on gas but when on petrol, it runs rough around maybe 600-700 rpm. It sometimes can stall. The problem is when i even touch the accelerator pedal the engine drops the rpm and like clogs up and stalls, even if engine is warm. When it is in neutral or even changing gears the car loses almost all power and stalls, I can get it to drive but each time i let of the accelerator or try to shift gears car stalls or almost stalls. I changed my fuel pump, got new spark plugs ( it didn't even start when i got the car, I had to try keep like 3k rpm and pump the accelerator to even try to keep car running on petrol, but when engine temp reached over 45"C then autogas turned on and car was like new and run no problem) Also diagnostic shows codes for: fuel trim level exceeded fuel trim 1 fuel trim 2 missfire, 4, 5, 6 cylinders Only time it runs perfectly on petrol is while Secondary air pump is warming up the catalytic converters. When the pump shuts off then the stand still rpm drop from 1k down to 600-700rpm, when it drops then it starts to stall when i touch the accelerator. I have never owned a petrol/cargas powered car so this is all new to me. Weird thing is that car runs like new on autogas. I hope I wrote something understandable, my english isn't the best. Maybe you can help me find the problem. As i was told, the DISA valve was okey, so I thing maybe i should look for vacuum leaks. ( and should I do a secondary air pump delete? I'm totally new to this car world sadly, but you live you learn as they say... )

    • and I haven't checked this ICV yet, but I will when I'll get the car back. It is at mechanics shop now, they are changing the subframe bushings.

  • There are many reasons for poor idle condition; vacuum leaks, dirty throttle body, O2 sensors, TPS, etc. You have to systematically eliminate potential issues. Certainly a bad IAC is among them.

  • Thank you sir

  • I would recommend not using carburator cleaner. It contains a dry lubricant that can gum up the needle seat assembly after cleaning.

  • Idk my car revs itself when i steer and sometimes idles at 500, 1100, 900 or it fcking dies It should be 900 or 1100. And if the revs drop the needle stops at 1400 for solid 2 sec and then chooses one of the 4 options above. That valve has to get hardcore stuck the entire time

  • Hey Chris, kinda stumped. I'm in a really cold state, the past month has been below freezing. When I turn on the car on days below freezing, the RPM flutters constantly during idling. I don't seem to have this issue on warmer days. Is this a sign of an potential issue with the IAC?

  • Chris is it possible to replace it

  • When an engine starts shaking Like that and the RPM goes down That's called surging which means that the engine is running lean or running out of gas thus it starts doing that shake And the RPMs go low

  • I love you chris fix you solve all my problems :)

  • why does my honda iacv have coolant pass through it?

    • So it doesnt stick closed from moisture buildup in the winter.

  • Hey Chris, desperate for a solution! My iacv keeps getting clogged from carbon buildup. I’ve owned my 1998 Toyota Harrier for 3 months now and have had to clean it multiple times. What’s the reason for this? Thanks in advance :)

  • What about if my rpms jump up and down quickly? Same solution?

  • Hey Chris, what are your thoughts on rough idle with the 5.3 Chevrolet’s? (Specifically 2001 Suburban) They just seem to have somewhat of a rough idle. I read one time in a forum that a guy was able to seemingly determine that it was due to the ethanol in today’s fuel. He was able to run his Burb on ethanol-free fuel and he stated that it idled steady. Ever heard anything like that? Thanks for your time!

  • when i’m done driving and put my car into park it will noticeably shake and drop rpm little below 700 any idea what’s the issue? only seems to happen when goes into park maybe reverse 1 time

  • PCV is just as easy and should be changed at the same time. It can easily be just as clogged. They are super cheap.

  • Am I supposed to dry before installing??

  • Don't count out a vacuum leak.

  • Why just clean iac should do throttle body also dummy

  • I want to know if its still good to clean this on my car when it doesn't idle poorly, just doesn't feel smooth when accelerating through the lower gears? And when i press the accelerator, there is a short delay but when i press it down more then it works as it should. It jerks a little too. A 2009 Renault. Could this be a dirty throttle body/IAC?

  • It's not a motor it's a solenoid. And you should use the meter measure the solenoid coil. A bad solenoid will be infinite ohms or open circuit. Also swelling around that housing is it an indication that hid has stuck and overheated and should be replaced. I'm just saying

  • You can make your engine look really nice with tire foam.

  • So maybe that's why my muffler shakes now.

  • I really enjoy watching your vids. Very educational!! Thank you.

  • I'm kinda new to checking for engine problems, but my car starts at 2,000 RMPs and takes 5 minutes to idle down. I am concerned if I should change/clean up the idle control valve ? Also, my car would sometimes stall when I try accelerating into the freeway.

  • Hey could this by any means cause check engine light and code p0101? No vacuum leaks and harness is checked good as well as new MAF sensor installed. Or could the EGR valve also cause CEL and p0101?

    • on intake temp of 20C

    • also the old maf reading on idle was 12g/s and the new one is 8 to 9g/s.

    • @ChrisFix Hey man i really thank you for the reply. yes i did reset the codes but they come back after a short drive. someone said the battery may need to be replaced which was in bad shape and i changed it because it was only 11.5V so i thought maybe the sensors dont get enough voltage but nothing changed after replacing the battery. someone said it can be EGR valve or restricted catalytic converter or exhaust leak but i thought all these actually have sensors and i should get their codes not the MAF no?

    • Did you reset the codes after you installed the new MAF sensor? Cleaning it shouldn't cause codes unless it was already broken!

  • Could a fluctuating acceleration on a electronic throttle body be due to a dirty throttle body or MAF?

    • Yes, I would give it a clean and that should restore the acceleration!

  • I just did this twice and it didnt work. Do you think it is just a bad iac valve or another problem?

  • would this cause misfire too or no?

  • Hey Chris! I've been binge watching your channel for about a year now. I paid a tow truck to move my old sister's Foxbody to my garage and it is now mine. Not only do I enjoy referencing your videos, but I enjoy hearing the excitement in your voice as the years went by. really shows how passionate you are with what you do. THANK you and keep it up!!

  • Rip my carbureted 429.... its idling a little choppy but I couldn't find the IAC

  • I gotta '92 chev and my idle made my truck die all the time when I first bought the truck. This helped so much. I can drive it like it's new. Thank you chrisfix you're by far my #1 youtuber for anto mechanics repair. I thought it was throttle body.

    • I'm glad this worked well for you!

  • With all the suggestions on how to fix my car, I'm going to end up becoming a mechanic.

  • Hey chris my 2004 f150 5.4 idles weird it goes up and down and shuts off

  • You have a video on cleaning a throttle control valve with out taking it out because I dont have a computer to reset the throttle thanks bro

  • Thanks men your the boss...

  • Where is at on 2016 Hyundai elantra? Thanks

  • My mustang shakes a little at idle once it is warmed up after sitting, is this a problem?

  • cAN i USE mass Air FLOW CLEANER TO DO HIS OR DIOESNT IT HAVe to BE TRONGER LIKE CARB CLEANER? oops caps sorry to lazy to rewrite

  • You must have the biggest ego EVER to have your name and logo on literally everything

  • If it was stuck open could it throw a check engine light saying the mixture is too lean?

  • Excellent way to explain the cleaning process greating from Paraguay

  • We've always pronounced it "Eye-yak".

  • guys I'm a mechanical and hes videos is harder than u think he work hard and I respect him ☺

  • Hi ChrisFix another helpful video. One question pls, you mentioned the symptoms my Honda CRV has perfectly. However, if I don't warm up my car for at least 5 minutes it will stall, then it runs normal until it cool downs again. I will clean IAC, it can't harm, should I also clean my mass Airflow sensor or just try IAC clean first? I appreciate your help. Everything you show is accurate. The other day I replaced my brake pads, rotor and the breaks worked like dream. Thanks for all your instructional videos, what are blessing you've been. Seriously saved me thousands of dollars and grief.

  • show us how to do a engine rebuild

  • Yup thanks for the tip clean my iacv on my Acura Rl 1996 and it idles normal it was ideling low it idle a lil higher now so my car don’t stall no more at a stop. Planing on putting a new iacv in the future and flush the coolant and new hoses .

  • So cool watching you work on this car! Can’t wait for the next video on it!

  • With ChrisFix, I can do anything with my car 👍🏾👍🏾

  • I was losing my mind for years, watching these videos... Plugs, wires, fuel pump, air leaks, ECU... My problem was a bad distributor.

  • Could this cause my truck to bog down and die while puffing white smoke out the tail pipe

    • My truck is a 1995 ford ranger XLT 2.3 l 4 cylinder

  • On my ranger when I have it gas and let it fall back to idle it would shudder so I just turned the idle up 👍

  • Yay I’m going to do this because I’m still in quarantine

  • could this cause stalling at stop signs? My car will stall sometimes when I hit the gas from a stop.

    • Yes, I would clean it (along with the throttle body) and that should fix the issue!

  • I did this. Mine was a little different and had 4 bolts...maybe it was a different part. Regardless I did this to it and just like it said, my rpms increased to be about 800!!

  • My truck had a high idle occasionally. I would just slowly let the clutch out while holding the brake to force the RPM down for 2 or 3 seconds then it would idle fine until it was left to fully cool down before using it next.

  • Hey Chrisfix! I have a 2003 Chevy astro, I have done everything in the video as well as replaced a lot of parts on the van. I have a rough idle when I put my foot on the brake when in gear. the harder you press the brake the worse the shake, soon as you put it in park its fine. this van does not have a brake booster, the powersteering pump and master brake cylinder are together. (powersteering gives power brakes) I really need help with this I have replaced a lot of stuff. I have replaced motor mounts, transission mount, crankshaft position sensor, 3 new distributor caps, new spark plugs, new spark plug wires, brake master cylinder, Idle pully and blower motor,oxygen sensor, fuel pump, fuel filter, new computer, catalytic converter, pcv and hose, and new Idle air control valve. When I had the reman module replaced at dealer they said the pcm randomly misfires are still present, and needs more diagnostics for misfires. Your my last hope......

    • Might be a vacuum leak or brake booster going bad, if it can't hold vacuum then that could cause your idle issue

  • Hey Chris Aren't You supposed to make a video about how to replace your stock steering with a race steering wheel?

  • Anyone have a guess what Chris is using for a headunit? What tablet/droid radio?

  • Brother , I love your videos you were definitely meant to do this...keep up the excellent work.

  • @chrisfix please help, I followed this video.cleaned the IAC valce, the throttle body and still idles poorly, then i took it to Autozone to hook uo the obd2 and it shows that I has misfires, so I replaced the spark plugs, didn't fix it, i replaced the ignition coil amd spark plug wires and still didn't fixed it, so now I'm fixing things and buying parts that doesn't fix the ilde problem, then obviously I did checked the air intake filter, and the sensor everything is good, so I must be missing something. All help would be greatly appreciated.

  • Hey Chris, I have a 2015 Ford Focus 2.0 FFV that has been having idle issues. It has also been throwing a bad O2 sensor recently. Could having a dirty IAC valve cause this code to pop up? Thanks for the awesome video!

  • How many of you cleaned the IACV kn your vehicle and it didn't fix it? As usual, this is one of may reasons that can cause a poor idle, but a parts changer mindset is what you all want instead of actual diagnosis and data. Don't guess, test.

    • @ChrisFix That's what you show then, how to determine xyz. This type of video just sells carb cleaner and gaskets.

    • Exactly why I made sure there wasn't any kind of vacuum leak or bad plugs or some kind of blockage in the fuel system before doing this!

  • Where tf did you get a 2014 Maserati from

  • Hey Chris please make more videos because I binge watch your stuff

  • My Ranger didn't want to go into a fast idle RPM when first starting the truck up in colder weather. I learned about the IAC on this channel, and replaced this item new figuring the truck was starting to have lots of miles on it. It was a quick fix, and the idling is perfect. Then I started to hunt for other small items to replace on my old truck. My recent purchased part is an Ignition Coil, but I'll wait and change it in the warmer Spring weather. Last fall of 2020 on my 02' Ranger 4.0L, we changed the thermostat, it's housing, hoses and sensors, and hose fittings. Then the valve cover gasket. I remember when work was hard work, but now its just to much fun since watching this channel . Sometime I'm in the garage late at night, and the wife thinks I have a GF. I'm Kidding.

  • ahh, got some food now time to watch some ChrixFix Reruns 😂

  • Can I use mass air flow sensor cleaner or WD-40 to clean it ?

  • I have a 19 Altima the dealer said I have computer stuff or something? Is that true? I literally just first time clean my brakes and got em super shiny. Calipers and I finished about an hour ago I just showered but I finished. Thanks to you. Took me 4 hours.

  • Do you bite your nails?

  • I have a question will the little peace inside the transmission that looks similar to the idle air control valve? Would it also help with the idle if the oil was easier to flow through the tiny holes filter that's inside the transmission? The little sensor inside the transmission.

  • Does the iac valve sensor have alot to do with it? Because i switched my iac valve with a brand new one in my truck, and connected the senser now its even more accelerated

    • Does it still idle poorly?

    • Someone plz respond

  • Hey Chris, my girlfriend's 2012 subaru legacy shuts off if you come to a stop without being super gentle with the brakes. It idles a bit low as well, but would this be a fix for it? Thank you so much man, I love the videos

  • Great work, great explanations

  • I don't even have an idle issue but I watched the full video lol

  • Hey chrisfix!!! i have a question! Did you teach yourself about cars ? did you go to a school ? family teach you??

    • @ChrisFix i have learned a lot about cars just from you ! You always go into detail about everything and show every step! After i graduate high school this year , i am thinking about going to pennco tech for automotive ! I work at a shop right now , and i’ve only learned brakes , change oil , tires and simple stuff , i want to learn more and i really enjoy everything about cars !

    • I've been working on cars since I was young with my Dad!

  • Hmmm...I'll have to give this a shot

    • Let me know how it works!

  • 1:18 🥶🥶

  • If anyone is interested, this is an informative vid, just not totally correct. I have been working on cars for about 45 years and know some dealership mechanics. They all say never use a toothbrush on throttle bodies. Also use throttle body cleaner, NOT carb cleaner. The bristles on toothbrushes are too hard and could etch or wear away some of your TB which is aluminum. Also carb cleaner has stronger chemicals and could damage some of the rubber or plastic in your TB.

  • I tried cleaning my (unaccessible to a newbie) EGR valve by spraying cleaner for 1-2 second bursts into the air intake tubing while maintaining revs at 1500 and then going to 3000 10 times every few minutes. Needless to say my turbo is now shot :( Guys, don't watch other YT channels. ChrisFix is the only channel you need.

  • Man I love your videos but I have a Ford Galaxy and the engine is backwards. To get to the EGR valve and IAC I have to take the turbo off which is behind the engine and I am a newbie fixer! :(

    • Darn! Are you able to access from underneath?

  • Hi, I live in Indianapolis, and I couldn't find an engineer to put the turbo on my 2011 Bmw 335is convertible would u like to do it I'll sended to u and we will talk🙄

    • I'll be making a turbo installation video soon! Stay tuned!

  • You are so badass! So glad you make the best detailed videos! You seriously freakin' rock! 🙂 Love all your videos!

  • How to lubricate turbo peoperly

  • Excellent video Chris as always. Can I suggest you do a video with cleaning the TPS sensor.

  • Man you are a legend. You tips are absolutely amazing. Makes me want to clean all parts of my car.

  • I HAVE THIS ERROR code p1504 ford expedition 1997? its idling low when its cold only! do you recommend that i replace or clean IAC valve?

  • i’ve had this problem for about 3 months now and couldn’t find anything on why it does it so i lives with it then i watched this and u explained exactly what is happening to me thank you again for your help

  • Do you need to clean out the residual trottle cleaner with distilled water or wait until it dries completely?

  • Do you wait for IAC's to dry up before reinstall? It wouldn't be smart to try snug inside same paper towel to dry them up. Or can they be reinstalled slightly wet from the spray?

  • awesome, will try that for my 23 year old vintage, rpm is bouncing up and down while idling in hot engine..

  • Great video Chris. Have you ever thought about doing Diesel Truck tutorials?