High pitched noise from throttle body with engine off and vehicle in run

[MrFahrenheit]

Do all 3.6L's have a high pitched noise from the throttle body with the engine off and the vehicle in the run position? I know it's that because I can unhook the harness from the TB and the noise goes away. It might do it with the engine running too but I just can't hear it over the engine itself.

No codes or lights and everything drives fine. It's been doing it for as long as I can remember.

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[SteveInOrlando]

I need to check that. I have a highpitched whine from mine, at first I thought it was the SC until I realized it does it when not running last weekend.

 

[SteveInOrlando]

@DAVECS1 you are the resident expert dealing with tuning and supercharges, have you seen this before?

 

[DAVECS1]

It should not be humming that means it is keeping a position while off and that ahould not be happening. But I need to hear rhe hum and see the theottle body and data.

 

[MrFahrenheit]

Here's a YT video of the whine mine makes. This is key on in the Run position. 2020 JTR. I have the airbox removed so you can see the TB. I unplug it and the noise stops. Plugging it back in does not make the noise come back until the key is cycled off and back into the run position.

 

[DAVECS1]

The position sensing seems like it is off. look how the throttle body moves when you unplug it.

 

[MrFahrenheit]

Yeah, I guess my original question was more of ‘is this normal’. Seems that it is not.

 

[SteveInOrlando]

The position sensing seems like it is off. look how the throttle body moves when you unplug it.

Is there a calibration for that? I don't see one in the the scan tool. Is this something we can request HP to look into, or am I throttle body shopping?

I have also recently started getting Airflow greater than expected when sitting stopped at a redlight sometimes.

 

[DAVECS1]

There is a throttle relearn in the VCM tool but I have never had much luck with it. That error makes sense if the throttle is hanging open.

 

[SteveInOrlando]

There is a throttle relearn in the VCM tool but I have never had much luck with it. That error makes sense if the throttle is hanging open.

yeah, I tried that. All it is relearning is the pedal position. Same a the brake relearn.

I can seem to find the sensor part numbers. I remember when we got my Maggie in the MAF was damaged in shipping. The shop found another MAF that was the same part number as the one that came with the Maggie.

I am torn if this would be a throttle position sensor, a throttle body position sensor, or the throttle body. I think I will check my scan settings and see if I can see the TPS sensor output. I know there is a reading for applied throttle, but it isn't clear to me if that is calculated or reading the current TPS reading. I would love to diagnose it down before throwing money at parts. These aren't super expensive, but I hate to waste money and have extra parts laying around.

 

[DAVECS1]

Steve. I will message you my latest channel config. It has a section just for throttle and pedal.

 

[jac04]

Mine has made the same noise since day 1, although maybe not as loud. I remember reading other reports of the same noise, either here or maybe on the JL forum. It seemed to be common to the JT/JL 3.6.

I also have, and have had, other cars with electronic throttle bodies that make a similar sound. The strange thing is that my 2014 JK is silent.

 

[DAVECS1]

I can tell you one of the most difficult issues I have faced offering tunes, is how temperamental, the throttlebody airflow model is. I have three different customers at the moment, we are trying to get this under control.

And there are a number on here that can tell you, I have had to address it on their rigs in the past. When the power is low enough, I don't think it matters much from 0-30% pedal, this is also why some people feel like there is dead pedal off idle, cause there is. When people go forced induction. There are way more functions that need squeezed in, during the 0-100% slide. Throwing away the first 30% makes drivability feel off, and is how many of the OEM tunes come from other manufacturers.

 

[SteveInOrlando]

So, I have figured out that the relaxed position of my throttle body is 6.4% throttle with no power applied. As soon as I apply power, the throttle body moves the throttle blade to match the min desired throttle. As such, it is closing the throttle body and holding it in a position. My video perfectly matches @jac04. When unplugged you can the the throttle blade move to it's relaxed state which is open somewhat, not fully closed. Is that supposed to be idle throttle position? The good news is the throttle position sensor seems accurate, so it isn't that.

I am trying to get @DAVECS1 a scan file showing it with the parameters he needs.

 

[DAVECS1]

Aint gonna lie. It would be interesting to see what another throttle body does, woth all the issues we have had.

These engines are starting to make me a tad frustrated, as it seems there are a number of parts that are different and have quality issues from truck to truck in the same model year. The thing that really gets my goat, is the parts are not broke they just don't run optimized. The owner gets some misfire, throttle bounce, and overall reduced power, but it is not entirely noticeable unless you drive it back to back with a good truck or log the data and know what to look for. I will get a number of guys that are over the moon with my tune offerings and then a guy will load the tune and I have to wonder did he actually load it on a jeep. Then I have to start doing math and sending revisions to figure out what part is causing the issue.

Sorry just had to rant.

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