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Discussion Starter · #1 ·
I did a search on this topic and found an old thread, but was instructed to create a new thread rather than revive the old one. So here goes, my apologies if this has been asked and answered.

I have a 2008 GT500 that I bought last October. The supercharger boost gauge has never worked. I have been on the track at Thunderhill, so I have definitely dropped the hammer, but nothing on the gauge. I have NO desire to modify the interior, I just want the stock gauge to work. Does anyone have any suggestions? Also, do not ASS-U-ME I understand mechanic talk. I have to Google everything. I can follow clear instructions very well, I just don't truly know what all the parts are called. LOL - please don't judge, we are in a safe place here, right?
 

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2012 & 2021 GT500 strippers
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Is your car modified? If so, what are the mods? The factory boost gauge doesn't actually measure atmospheric pressure. The gauge movements are based on airflow calculated by the pcm, so chances are if it did work, it would be wrong anyway. The exception would be if the engine and tune are stock. If it is stock it should appoximate boost. If the gauge is not working at all, I can't help you.
 

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Discussion Starter · #3 ·
Thanks, Catmonkey. As far as I can tell, it has NEVER been modified. Which is why I am not looking to add an a-pilar or one of those vent gauges. I would like to keep it as stock as possible (call me old school). The gauge actually being accurate is really no concern to me. I just don't like having a gauge that sits dead.

I am no wrench monkey, so I am open to all suggestions that may seem "obvious" to anyone. Maybe there is a cable that is loose, where would I look? Perhaps a sensor is attached somewhere. Where would it be and where can I get a replacement?

I won't be offended if you treat me like a complete newbie. ;)
 

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Moderator/Admin Dude!
2020 CFTP Red! 2011 Kona Blue
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I won't be offended if you treat me like a complete newbie.
Just to make 100% sure… get the car in 3rd gear and about 1500 RPMs… then absolutely MASH the gas pedal to the floor. Did your boost gauge move…?

I moved your thread here to our problems section.
 

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It’s possible it’s a failed stepper motor. As others have said, it’s a pseudo boost gauge anyways and if it wasn’t getting a signal you’d most likely have other PCM issues. Stick needle / failed motor would be my guess
 

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I suppose it could have a fuse associated with it. You might check for that.
 

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Just to make 100% sure… get the car in 3rd gear and about 1500 RPMs… then absolutely MASH the gas pedal to the floor. Did your boost gauge move…?

I moved your thread here to our problems section.
^^^^^Yes, that is what I experienced with the original boost gauge in the dash cluster, it never moved when driving around and the engine not under boost/load. It required a scenario as you outlined above, a higher gear a lower rpm to see the gauge move because that forced a boost/load scenario. Before that I'm sure it moved but my car was gaining speed quickly and I was sure not worried about the boost gauge as things were coming at me and going by quickly while I accelerating moderate to hard..........

R
 

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^^^^^Yes, that is what I experienced with the original boost gauge in the dash cluster, it never moved when driving around and the engine not under boost/load. It required a scenario as you outlined above, a higher gear a lower rpm to see the gauge move because that forced a boost/load scenario. Before that I'm sure it moved but my car was gaining speed quickly and I was sure not worried about the boost gauge as things were coming at me and going by quickly while I accelerating moderate to hard..........

R
Yup, I was in the same place for the first few months. I was actually pretty excited when I saw it move the first time cuz I had the opportunity to take a quick glance. Kinda like how I didn't look at the speedo much during the ShelbyFest fun cruise for similar reasons. :)
 
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Discussion Starter · #9 ·
Goose, not only was that a FUN way to test it, it turns out it worked! I was in 3rd gear around 1500 RPMs, dropped the hammer and the gauge responded!

So I guess it does work, just useless! Thanks everyone. I am good with this. ;)
 
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Moderator/Admin Dude!
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Goose, not only was that a FUN way to test it, it turns out it worked! I was in 3rd gear around 1500 RPMs, dropped the hammer and the gauge responded!

So I guess it does work, just useless! Thanks everyone. I am good with this. ;)
Excellent! Glad to hear it’s all normal/normal. You aren’t the first to think the gauge is dead. It sits at zero most of the time... until you aggressively mash the pedal. The gauge isn’t “worthless.” It’s an accurate reading of inferred boost. The only time it becomes inaccurate is when you mod the car to have more than 15 psi or a tuner screws it up.

Enjoy and happy boosting! 🤟
 

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2008 Vista Blue with White Stripes
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Boost Gauge Owner's Manual: Drive it like you stole it.
I 'researched' my boost gauge after dropping off KurtDog back at his workplace once we returned from our visit to the bank where I paid for the car.

It worked then, as well as the already 50,000+ other times I wanted to confirm it 'still' works. But I will maintain vigilance just in case..... :ROFLMAO: :ROFLMAO:
 
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