Symptoms of a Bad Idle Air Control Valve (IAC)

Рет қаралды 56,130

8 ай бұрын

Common symptoms of a bad Idle Air Control Valve (IAC) and how to fix it. Read here for more information: www.backyardmechanic.org/symp...
An Idle Air Control (IAC) valve is controlled by the computer and allows air to bypass the throttle body butterfly plate.
Some Newer vehicles don't use an IAC but have an Electronic Throttle Body (ETB) System, which controls the throttle butterfly plate.
A bad Idle Air Control will only affect the idle of the engine, but engine will run well when the gas pedal is pressed.
Symptoms of a Bad Idle Air Control Valve
Idle Speed Erratic
Idle Speed Too High
Idle Speed Too Low (Stalling)
DTC Error Codes (P0505 to P0509)
How To Fix a Bad Idle Air Control Valve
An intake air leak can cause the same symptoms as a bad IAC since it is letting air in around the throttle body.
The most common fix is to clean the IAC of carbon build-up, but it may also have failed or have a wiring issue.
If the IAC is cleaned, the engine may run badly for 2-3 minutes until the cleaner is burnt away.
By using this information user assumes all risk of use.

Пікірлер: 35

@vincentbryan1962 3 ай бұрын

Thank you for making this video. I drove 30 miles with bad IAC. Ended up not hitting a single red light so I had my foot on the gas the whole way.

@carriersignal Ай бұрын

Wow. This is a very good video. My car is exhibiting the very symptoms you describe. It runs fine going down the highway, but as soon as your press the clutch in, its RPMs drop and it stalls out. It also seems to occasionally idle at a very high or sometimes erratic RPM. It has been setting for a while in the garage. This will be the first thing I take a look at along with any air leaks. Thank you!

@georgehooper6955 8 ай бұрын

Great video and explanations! Nice and direct

@johnmcnulty6392 5 күн бұрын

Great Video! I have a 2006 Jeep Grand Cherokee and recently put new heads on due to bad head gasket, also new timing chain kit along with brand new OEM catalytic converters. When i was taking the Cruise cabe off the throttle body i broke the nub that the cable clipped to so i got a used throttle body and rebuilt mine. The issue i'm having is sporadic idling and when going down the road i have to mash the accelerator to get it going. Stops are worse trying to get going. I have replaced the IAC and that did nothing , The data on my scanner is saying the IAC has high input voltage. I was told with me rebuilding that throttle body it is probably out of spec, So i ordered a new throttle body with both new sensors IAC and TPS . I installed the New throttle body last night and its still the same running ruff and still have High voltage at IAC. Can anyone lead me too what might be causing this High voltage? I can't find anything besides replacing the IAC. Instructions with the NEW Throttle body say's the IAC needs Idle speed relearn and i cant find anything for my jeep how to do this. Also as last night im throwing a code of UO41, Witch i just watched your video on that before writing this book. Thanks for that as well. Any help would be appreciated. Thanks

@davepatt6018 2 ай бұрын

Thank you bro that's good information to know

@Warzone4.9 5 ай бұрын

Thank you

@juliansdiamonds 5 ай бұрын

Great thank you

@jifcks4320 3 ай бұрын

What happen if the iacv hose line has tiny leak ?

@Hardwick989 2 ай бұрын

Its the same issue with mates Toyota hilux. Prob mid 80's. Trayback . I pulled it off and cleaned it. Good for 2 days then back to over reving, about 2100. It is the idle sensor, electric that controls a magnet i think to turn the shaft inside. Ive minipulated the shaft and confirms its faulty. But only the magnet! End where it has a elec plug.

@johnf.6942 5 ай бұрын

Good video! I have a 2015 Nissan rogue, runs great first 10 minutes or so , but vibration starts and is present at stops, and at idle. I Cleaned up throttle body, mass airflow sensor, new filter, new pvc , no cracks in any hoses, new engine mounts, new 02 sensor, pre cat, no codes, fuel cleaner in , fuel trims are good … …🤔.. any thoughts?

@franzapolski8863 7 ай бұрын

Hi, my name is Fran I have a 2008 Saturn Arua XR 3.6 with Idle problems changed the throttle body and checked for a vacuum leak checked some wiring still the same problem. What's next? Changed the throttle body because had a low-speed warning light.

@21gonza21 3 ай бұрын

Does it suppose to leak or vacuum air thru the idle control valve ? I did a smoke test and smoke came out of the control valve

@swimwithcoachraven1532 2 ай бұрын

Mine didn’t have a cel when idling as soon as I hit high rpm the cel comes on. Now it comes on as soon as I start the engine. It’s just got worse

@user-uw7gf4xp4n 5 ай бұрын

Mine does those things but also after it's warmed up when I put it in gear it dirs

@ricardogonzalez3032 Ай бұрын

2016 cryshler 200 2.4 once you have it in reverse engine stalls,replace motor mount.transmission mount same thing did tuneup spark plugs coils,pcv,clean throttle body

@kamalmahmood406 3 ай бұрын

Great video, thanks. How do I differentiate between malfunctioning Idle air contole valve and leaking air please?

@jakub4976 2 ай бұрын

Try feeding smoke in the Intake. While it is running. The vacuum lean should reveal itself w smoke if you have a vacuum leak

@dfields9511 7 ай бұрын

IAC vs bad TPS thought ?

@adamc4155 3 ай бұрын

Have all the symptoms, but the engine code is a misfire p0300 code and a misfire code for all cylinders.. already checked all the usual culprits, the iac and egr are among the last to check besides possible vaccuum leak..

@proroofersncllc-vb8rl Ай бұрын

I had same code my issue was water in the gas tank, dumped pit new gas on it and truck runs again.

@adamc4155 Ай бұрын

@@proroofersncllc-vb8rl might have to do that.. it's either that or the ecu is burnt out

@tracemiller1519 Ай бұрын

I’m having the idle problems bad but I’m having codes like p052c cold start and other codes like camshaft/crankshaft correlation sensor and timing codes, could the AIC or throttle body cause such things??

@HVAC_Mechanic Ай бұрын

It will need to be troubleshooted, but that sounds like a timing issue such as a slipped timing chain/belt.

@nony350 2 ай бұрын

What about the engine nice and hot and push on the pedal while in park an it idles high like 3 rpm’s then after 10 sec or so it starts to idle down to normal is that a sign of bad iac too ?? Code shows p0507

@HVAC_Mechanic 2 ай бұрын

I made a video on a P0507 code. Here is a link kzfaq.info/get/bejne/e9OAY9x12M7beZc.html

@markanthonybokeron1860 11 күн бұрын

Hey bro. My car is 2006 honda civic coupe 1.8… does it have an IAC valve or its called purge solenoid valve??…coz i cleaned my throttle body using cr throttle body cleaner. After that the idle is too high and fluctuating and the engine light turns on. I reset it manually by gaking the negative wire on the battery. and by the way i scanned it and the code is po505 .. doni have to replace the purge valve that is attached to the throttle body???

@HVAC_Mechanic 11 күн бұрын

The purge valve is for the EVAP system used for emissions, which is separate from the throttle body idle. If the purge valve is bad, it will usually give an EVAP code. With a P0505 code, there is still an issue with the throttle body. Usually, it is dirty and needs cleaning, or a component has failed, but it needs to be troubleshooted.