Engine Revving Up and Down at Idle FIXED

Car won't idle normally? Engine surges or revs up at idle? Mine used to as well, until I discovered what the problem was. I replaced multiple parts that may not have been needed to fix this issue. Hopefully this video help someone else out.

The car used in this video is a Hyundai Elantra 2001. Same or similar engines: Hyundai Accent Elantra Tiburon Tuscon Kia Spectra5 Saab 9-3 9000

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Troy's Garage YouTube
4956 West 4800 South - Box 235
Salt Lake City, Utah 84118

[skenginmyblazer]

I got a bmw 1 series 2.0L diesel and 80% of the time when I turn the car on the idle revs drop every second and then come back up again it also does it when I drive so it feels like the car is jerking and pulling but I have no clue what it is and I can’t find anything similar anywhere can anyone help?

[ItsMikeHalk]

Finally a video with a 16 valve Hyundai engine repair with useful information.

[SuperBanjo]

I had a bearing going bad in the alternator. It would turn hard sometimes and smooth sometimes. When the bearing would hang up a bit it would pull the engine down causing the computer to open the throttle to find the idle point it wanted to see, when the bearing would smooth out it did the reverse causing the engine to speed up. As a result of the bearing doing that the engine would idle up and down erratically. There are bearings in the alternator, power steering pump, water pump, A/C compressor, tensioner pully, and idler pulley so any of these could cause this problem. Anytime you unplug the throttle body or remove it from the intake you have to reset the computer and let the car idle for about 15 minuets with no load so the computer can relearn the idle settings. This needs to be done when the vehicle is cold with no electrical load and up until the engine is warm so the computer can learn the different positions to hold the throttle body plate at different engine temperatures, that is why you need to let it idle for 15 minuets or so.

[ostralopiteq]

Hello sir, yesterday I had the same problem, and after watching your video, I searched and found a leak in EGR tube causing the truble to my engine, and i fixed it, you saved me lot of time and money sir, so thank you very very very much.

[lebronjordan]

Nice to see father taking good care of his daughter 🙂!

[dohcameraman]

I love the way that video ends “I Love Manuals!”

[jvst]

Thanks u for this video that gave me another clue why my car is reving up and down and stalling then just dies before i start throwing parts at it

[jonathanwingo]

OMG!!!! I've been trying to find someone who had the same problem and made a video. THANK YOU!!

[Electux]

Same issue in a 01 focus, no codes. Only thing I did before this was change the spark plugs 2 weeks before this issue.

[mikehigby]

You can take wd40 (non flammable) and spray it around all of the hoses and gaskets and when you hear the engine rpm's go up you have found you're leak.
To identify a vacuum leak is the issue before even wasting any time and money replacing sensors, hook up a scan tool and go to live data.
Go down to the short term fuel trims and see what % they are at.
If a vacuum leak is present, the fuel trims will be very positive anywhere from 5-25. This is the computer adding fuel to compensate for the lean condition the vacuum leak is causing.
press the throttle and hold it around 2000 rpm's. If the fuel trims go into negative or close to 0...you have a vacuum leak present.
This is because when you rev the engine, you are out of vacuum and in positive pressure.
Doing these procedures saves time, money and a dry scalp from scratching it too much.

[worshipwhilewewait]

What did it for Me was the smile on Your face when You realized "hey - I think I just fixed it!" GREAT video!

[jamesmarshall]

You are the MAN! I have a Ford focus 2.0L zetec... Exact problem you were having from start to finish. 10 + years now. Lots and lots of money spent all over and car would run fine for a while after replacing various parts then poof back to square one again. All these experts working on this car and all of them saying the same thing after replacing parts, that it's got to be a vacuum leak somewhere but they can't find it. In the morning I'm going to see if it is that gasket. I'll let you know when I'm done. Thank you so much for this post.

[JodBronson]

When sporadic idle, usually it's the " Idle Air Control Valve " or something to do with Air. Check for Air / Vacuum Leaks or Idle Air Control Valve not opening / closing correctly. Another possibility... Throttle Position Sensor or Throttle Body / Butterfly not closing correctly or dirty.

[onigiriworld]

Does this work for recent models, I’m having a similar issue but it also feels like it’s losing power when I’m driving around with a little vibrations too

[rockyhavens]

this guy is good, one of the best youtube on line, very good info !!

[fatwalletboy]

Sign language known the world over by diy mechanics to illustrate revs going up and down....wave hand around from the accompanied with a sound impression to match 😂

[dannyzukko]

He said schwing !!!! Very thorough garth

[MultiLupio]

*very good video in my case my ford taurus when I turn it on the rpm goes up to 1500 and then goes down to 600 and goes up and down but when it heats up it stops doing that, the codes show me injector number 3 and maf sensor or it could be the iac valve ? my car has these symptoms when it's cold when it's hot it does little*

[cassiem]

My Honda S03 civic does this. My mechanic replaced my intake with an bottle intake and said it will resolve the issue. The issue got worse. The jumping of the revs.. 2k to 1k then 2k again. Its very annoying. I need help. Cause it doesn't seem like they know what they are doing

[integrator]

Great job .. now do you have a video for the shocks.. My lady have a Hyundai 2005 we replaced the shocks but still have a bumping sound.. like to see how you do it