Vacuum Leak? Rough idle

[FrankM5]

This sounds very similar to what I was experiencing with my 16. I told my friend / neighbor who is a mechanic and he said clean the throttle body and MAF sensor. I tried it and there was quite a bit of residue on the throttle body, the MAF sensor was clean. It solved my issue. May want to give it a try, only takes 15 mins or so and cost nothing.

I will for sure try this! I might even throw back on the stock intake at this point lol.

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[coz0502]

I will for sure try this! I might even throw back on the stock intake at this point lol.

To be clear, I was replying to njweatherman, his issue seems very similar to what I experienced. When it happened to me, there was no shaking or stalling. Just a fluttering of the RPMs (100 - 200) when idling, while driving the issue was unnoticeable.

You're issue seems more sever, but still a good place to start before you start incurring cost.
Good luck.

 

[FrankM5]

To be clear, I was replying to njweatherman, his issue seems very similar to what I experienced. When it happened to me, there was no shaking or stalling. Just a fluttering of the RPMs (100 - 200) when idling, while driving the issue was unnoticeable.

You're issue seems more sever, but still a good place to start before you start incurring cost.
Good luck.

Sorry i guess the fluttering in RPMs to mean come off as a sort of shaking lol. But exactly what njweatherman said about his car is exactly what is happening to me, its only when the car is idling on a red light never happens while driving. RPMs goes from 600 to 500 as it hits 500 thats when the fluttering happens.

 

[coz0502]

Sorry i guess the fluttering in RPMs to mean come off as a sort of shaking lol. But exactly what njweatherman said about his car is exactly what is happening to me, its only when the car is idling on a red light never happens while driving. RPMs goes from 600 to 500 as it hits 500 thats when the fluttering happens.

Ok, cool. Sounds very similar or could even be the exact issue I noticed too and there was just enough goop on the throttle body that was causing it and getting the RPM fluttering. It was immediately resolved after I cleaned and started the car up. I hope that is the only issue with your car as well.

 

[njweatherman]

I will for sure try this! I might even throw back on the stock intake at this point lol.

Please let me know if it works.

 

[coz0502]

Please let me know if it works.

Me too! This is my 4th reply in this thread, I'm invested now, got to see it through to resolution

 

[njweatherman]

Me too! This is my 4th reply in this thread, I'm invested now, got to see it through to resolution

Glad to see I'm not the only one. Mine happened twice so far since the beginning of the New Year, which is not bad. I'm not mechanically inclined at all, so if the throttle body and MAF cleaning works, I will take it somewhere to be done.

 

[njweatherman]

Make that 3 times since the New Year. Today, it happened twice at a red light. Instead of dropping to 500, it only dropped to 550 or so, but I could definitely feel and hear it in the engine.

 

[blue5.slow]

So I've been having this issue with my car for a while and I figured out the issue. For me, I have a Roush cold air intake. These two barbs had holes on them that were not plugged, which I never noticed LOL. This was causing a vacuum leak. Stupid me for not realizing, but it's worth checking if you have an aftermarket cold air.

 

[njweatherman]

So I've been having this issue with my car for a while and I figured out the issue. For me, I have a Roush cold air intake. These two barbs had holes on them that were not plugged, which I never noticed LOL. This was causing a vacuum leak. Stupid me for not realizing, but it's worth checking if you have an aftermarket cold air.

Just a quick off-topic question. Did you notice a sound increase with the Roush cold air intake? How about a performance gain?

 

[blue5.slow]

Just a quick off-topic question. Did you notice a sound increase with the Roush cold air intake? How about a performance gain?

I did not, and for the performance gain I did not not notice anything, but I know I gained some horsepower. Only with the tune though, when I was running the intake with no tune I saw no gains

 

[Strokerswild]

My F150 just got out of service jail today after a week of incarceration. Both intake cam phaser solenoids were replaced, as the dealer was seeing erratic operation with both. Hopefully this is the end of the nonsense with this vehicle.

 

[njweatherman]

Frank and Chris,

I bought CRC Throttle Body Cleaner and Mass Air Flow Cleaner. My friend is a mechanic and we are going to clean them both today. I will post how it goes.

 

[njweatherman]

Frank and Chris,

I bought CRC Throttle Body Cleaner and Mass Air Flow Cleaner. My friend is a mechanic and we are going to clean them both today. I will post how it goes.

Frank and Chris,

As I previously stated, I had my throttle body and mass air flow sensor cleaned this past Sunday. So far, the rough idle has not returned. Today, I did a lot of stop and go city driving and it held up. So, hopefully, this cured it. I'm keeping my fingers crossed.

 

[NeedForGreen]

I had a simular issue. It was very random. Wouldn't always happen and I would always notice my rpm's slightly drop at a light before going back up. Not a huge difference, but notciable on the digital gauge. This past January during some cold days here I noticed my rpms bouncing a little more and my idle would be higher than usual. I took it to the dealer and they blamed it on the cold weather and told me no codes. I knew there were no codes, but knew something was off. I took it to another dealer 30 mins away. Found out I had a bad spark plug on #2 cylinder that was misfiring without tossing a code. Replaced it and all fixed. They actually took the time to look for the problem unlike the dealer that is 1 mile from my house.

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