Swap gauge needles and get accurate readings

[fisdad]

Many have asked about how to swap your gauge cluster needles and still get accurate readings. Here is how I have done it several times with my Alero and it has not let me down.

First thing:

Google what your motor should idle at or get an OBD II scanner to read your rpms.

Let your car idle for 20 minutes or until the fans kick on to be warm.

Fill gas tank to max.

Remove face from gauges so that needles are exposed.

Remove needles with car not running. (Pull straight out)

Start car with full tank and a warm engine.



Place temp needle just above center line and push it on. It should drop back down to center... If not, pull and reposition higher until it lands on center on its own and stays there. Turn key off then back on to verify smooth operation and proper position of the needle.

Next do the fuel gauge. Stock, mine always went about 1/10 of a tank above the full line. That's where I placed it. You don't have to be perfect here. The idiot light for the gauge works as it should regardless of if the needle isn't perfect.

Tach is next, with car running, do as you did for the temp gauge until the needle rests at proper idle speed. Use and obd II scanner to read your actual rpms from the computer if you have one available.

Speedo last. Download a free speedometer app on your phone. I recommend the basic and free one. Also use your gps reading if you have one. Put the needle on 0 and push very lightly. Compare your speed from your dash and app as you drive. Keep pulling the needle off and repositioning it as needed WHILE STOPPED. To get better readings. When your app and dash follow from a steady 10, 25, 40 mph consistently... You're good to go. I've had my speedo verified by my app, GPS and a police officers radar gun. It's spot on. It usually only takes me a couple of tries to get it right after pulling the needles.

[Shiwnath]

You can use an OBD2 Scanner for the temp, RPMs and speed. That's the method i used. And I confirmed speed accuracy with a GPS. As for fuel, IMO i think you should be more concerned how much fuel is left until the gas light. I waited for my gas light to turn on and then put the needle on the empty line. That way I can predict roughly how much gas is left before I need a fill up. By going this route, my car never hits the full line, but it's all about preference.

[fisdad]

Originally Posted by Shiwnath

You can use an OBD2 Scanner for the temp, RPMs and speed. That's the method i used. And I confirmed speed accuracy with a GPS. As for fuel, IMO i think you should be more concerned how much fuel is left until the gas light. I waited for my gas light to turn on and then put the needle on the empty line. That way I can predict roughly how much gas is left before I need a fill up. By going this route, my car never hits the full line, but it's all about preference.

I knew temp would read but gauges just have bars so its still a bit if guess work. I forgot about speedo on OBD II though. Thanks!

As for fuel... I'm not very worried about it. I know exactly how far I can push it.

[Shiwnath]

Originally Posted by fisdad

I knew temp would read but gauges just have bars so its still a bit if guess work. I forgot about speedo on OBD II though. Thanks!

As for fuel... I'm not very worried about it. I know exactly how far I can push it.

Luckily for us the Grand Am cluster has the actual numbers on it. The middle bar on our clusters represent 200 degrees F for USA cars or 90 degrees C for Canadian cars so using that as a reference should help with temp

Edit: also to ensure RPMs are set correctly, you can try hitting the rev limiter which should activate at 4K RPM while in park/neutral. This isn't suggested and should be the last resort as it puts unnessary strain on the engine.

[fisdad]

I hate grand am people now... Just for that! Stupid functional temp gauge bs.... ;p