JoeyJoseph

My 2012 Max has had a fluctuating idle from about 650rpms to as low as 550rpms at stop in gear and in park. The engine compartment has noticeably become more unsteady with a slight vibration with the low rpms. The weird thing is sometimes i experience a bit of a bogginess upon acceleration but sometimes performs as if it were new again when accelerating. It is a random problem that seems to be getting worse. The car performs great at highway speeds. Can the CVT cause a low rough idle? Another clue is the engine really bogs down at a stop when a load is applied like using the power windows or using the AC. Anybody out there cure these symptoms? Ive cleaned the throttle body, changed the sparkplugs, checked for vacuum leaks (seems to be none with soapy water and spraying sensor cleaner), changed out the intake idle air control valve, changed air filter, changed MAF sensor, and used Gumout fuel system cleaner with PEA a couple times. Any input would be greatly appreciated.

User1

How do you check for a vacuum leak using soapy water? I was not aware that gen7's had an IACV? How many miles are on your car? Have you tested your battery and charging system? Have you scanned for codes?

mahanddeem

Seems like a fuel/air ratio issue, vacuum leaks, air filter, MAF, dirty throttle body, cracked air intake, fouled spark plugs, worn ignition coils, worn oxygen sensors, etc.
Though you seem to have tackled most of these! Have you ever performed idle air relearn and/or throttle position relearn? it is a CONSULT procedure, paddle dance or CVTz50 can do the idle relearn, do some research on that.
Mileage? as User1 said, get a code scanner and see if you have a hidden DTC. I doubt a CVT can cause idle issues

JoeyJoseph

The soapy water method is like checking for a leak on a tire. The IACV is known as a Intake Manifold Idle Control Valve. I have 204K kms (not miles) on the car and the battery and alternator seem to check out with the correct voltages. There is no check engine light and no codes pop up with the scanner.

JoeyJoseph

Thanks for the response. I will try the relearn idle process today! Will keep you updated on the results. Car has 204K kms and there are no hidden codes popping up when using a scanner.

Richard66

You didn't load test the alternator or the battery? It needs to be done.
How old is your battery?
Reading voltages does not give you the health of the electrical system.
These cars can develop all kinds of problems when the electrical system is not up to par.

User1

Leaky tires are under positive pressure. Vacuum lines run negative pressure. Ponder that... These cars are fly by wire, no IACV. Like the previous poster mentioned, power and charging system first. Everything about everything on modern cars is computer controlled and needs clean power. You a Canuck too, eh?.

JoeyJoseph

Will give the load test a try. The battery is about a year old. And voltage checks out normal.

JoeyJoseph

Thanks for the helpful comments.

User1

Good luck.

Nmax5150

Try the simple thing first.. Clean that Throttle body .. if it is dirty.. it will cause a low or rough idle... Do not use brake clean.. only use throttle body cleaner .. just use a rag or micro fiber towel.. a tooth brush works great ..

Bluedawn0001

ive spent 2 hours on the car and online trying to find this dang part! I have idle issues when cranking as well as a code that says the idle air control is bad. I guess the 2012 is intake air control? But where is it? Driving me mad. Nothing online at all. It’s all gen 6,5 etc nothing gen 7

Richard66

Did you clean the MAF sensor and/or check for vacuum leaks. Both of those will mimic a bad idle air control valve, and will cause a rough idle
BTW what was the specific code you get?

mahanddeem

Where did you search?

User1

What part?

Bluedawn0001

sesrched all around that area. Nothing there. Took off the throttle body, nothing attached to it.

Bluedawn0001

i just started at the error first before looking for anything else. I’ll have to find the error but I remember it saying specifically the idle control valve was bad and the system was running rich. A few weeks prior to this one day got in it cranked it up and it stalled a few times. Took 10 min to get it running then it ran fine. No check engine light but put it on a computer anyways and it came back with a misfire code. So went online and see tons of post about the exact same issue with this car just like the one here (sorry for hijacking ur post figured same issue maybe get somewhere). It also hesitated at idle within idling in low gear and you hit the gas it will almost sputter. Also the lights seem to flicker a little (praying not a coil pack).

So bought some seafoam but then a other place said nah use good carb cleaner take apart throttle body clean it out, pull out iacv clean it etc etc. so can’t find it to clean it. And the throttle body wasn’t that bad $120k miles.

I did just have to replace bad radiator radiator fan and found a small radiator leak (will fix later). So not sure if motor overheating a few times could have caused any issues. But just seems a common issue so went to ground zero first.

User1

There is no IACV. You're looking for something that doesn't exist.

User1

Are you praying hard enough?

Bluedawn0001

P0507 - idle air control system RPM higher than expected. - idle air failure - idle air system has higher voltage than expected.

Reason for failure - high mileage and age

recommendation- check throttle body for damage before rebuilding.

Thats the code and info I got. Some people say it doesn’t have one but parts stores do sure sell one. It’s separate and seems to attach somewhere else.

Bluedawn0001

I trust oem parts never had an issue with them. With that being said I called a mechanic at the dealer so I can try and get this done. He went along with what was said above (already had it on my list to do) which was check for vac leak. Just for anyone else comes looking with same issue, he said this car and engine has issues on the left side with vac leaks. So adding that to the list.
Check and clean map
clean throttle body
replace throttle gasket
check for vac leaks

LtLeary

I am trying to remember all the vacuum line sizes and am coming up blank (I slept a few times since I did it) but it will save you a lot of time if you just start pulling them off and replacing them one at a time. With all the heat cycles, they do get fragile and crack. I think it only took a few hours max to replace them all and if you buy them in a retail shop they come in 6 or 10 ft lengths. I don't believe I used more than 1 pack of any given size.

User1

Granted I am using a '14 motor in a 5th gen body, but my vacuum connections were quite simple and I didn't have to plug anything that wasn't required for the swap. They are:

1) Bank 1 Brake booster
2) Bank 1 PCV
3) Bank 2 breather to airbox

Not much to it for vacuum lines. Bank one lines are pretty short, not more than 6" or so.

Should you opt for a TB replacement, here is a good deal OEM Hitachi unit:

https://www.ebay.com/itm/Fuel-Inject...6/323775766969

LWilspeed

TO OP: JoeyJoseph. Do your lights flicker? Like interior lights, or even headlights? And/or do you head a slight popping noise through your sounds system when activating electric loads (turn on headlights, etc)? If you notice either of these, I agree with the earlier advice to check charging system. I've seen this on 7th gens, including my own. Ended up being a corroded connection where the negative battery cable bolts to the top of the transmission. Takes some work to get to it because you have to pull the battery tray out. This is a long shot but I thought it might help. If you have the other symptoms just cleaning the cable end and the transmission boss it bolts too will do wonders for your car.

User1

OP is gone. Account creator passing through looking for a quick answer and maybe save a buck so they can get to work the next morning. There's gotta be a name for that type, no?

LWilspeed

Sorry, I just got excited about the first question.

VeeQue35DE

The IAC on your car is the electronic throttle body. On older cars, usually drive by cable, the IAC is separate and can be changed out. So new or old, it's there, but when it's electronic controlled and non-replaceable then it's not mentioned. You should go through the Idle Air Volume Learning procedure before you continue with a new throttle body purchase. It's free anyways and you'll have to redo the procedure if you buy a new one (so count this as practice). You may want to have a timer ready on your phone.

Start engine and warm it up to normal operating temperature. (Temp needle in the middle)
Turn ignition switch OFF and wait at least 10 seconds.
Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds. (K.O.E.O. - Key On Engine Off)
Repeat the following procedure quickly five times within 5 seconds. - Fully depress the accelerator pedal. - Fully release the accelerator pedal.
Wait 7 seconds, fully depress the accelerator pedal for approx. 20 seconds until the M.I.L. (Malfunction Indicator Light / Check Engine Light) stops blinking and turns ON.
Fully release the accelerator pedal within 3 seconds after the MIL turns ON.
Start engine and let it idle.
Wait 20 seconds then W.O.T. (Wide Open Throttle / Snap Throttle) two to three times.
Wait for the RPM gauge to settle back down and it should over between 600 to 750 RPM's nominal value.

Sal.1027

Has your issue been solved yet?