Temp gauge Jumping around when driving, help!

[Jboss12]

Hello r3v I just recently replaced my thermostat with an 88 degree thermostat from blunttech. When driving the temp gauge seems to be very spuratic. On the freeway today it was at 1/2 mark then it would randomly jump a bit higher then come back down to 1/2. Sometimes it would jump/skip up to 3/4 on the temp reading gauge and stay that way for about 5 minutes then jump back down.

Is this a problem with the radiator not being bled completely? I feel like the gauge must have something loose as well because it always skips when I start up the car.

Thanks in advance, James

[atldohc]

both scenarios are a possiblilty. if you havent tried already i would suggest taking out the cluster and making sure the grounding nut for the temp gauge is tight, as well as for the fuel gauge. i think they used a 7 or 8mm nut. any air pockets from incomplete bleeding can also cause your symptoms as well. a quick search will give you lots of tips on coolant bleeding. i had the same symptoms on my car when i got it and needless to say it freaked me out. after tightening the nut all was good

[Jboss12]

both scenarios are a possiblilty. if you havent tried already i would suggest taking out the cluster and making sure the grounding nut for the temp gauge is tight, as well as for the fuel gauge. i think they used a 7 or 8mm nut. any air pockets from incomplete bleeding can also cause your symptoms as well. a quick search will give you lots of tips on coolant bleeding. i had the same symptoms on my car when i got it and needless to say it freaked me out. after tightening the nut all was good

Nice! Thank you very much for your help. I will try and re bleed the radiator as well as check out the instrument cluster