Left the house today and about three minutes into the drive, I heard a series of beeps. I looked at the LCD display and it said "Engine Temp Hot". I then looked at the temp gauge and it was pegged on HOT! :o I then looked for a place to pull over and shut it down, but before I did, the temp gauge dropped from HOT back down to normal. I pulled off anyway and popped the hood. The temp seemed normal. It did not happen again all day. Scared the **** out of me. Has anyone else had this happen?

A number of members have had this and other gauge gremlins happen, but from what I know of the situation it happens once or twice then appears tof ix itself. You may if it persist take it to a dealer, but most havn't had it occur more than once or twice.

Check the thread on this problem in the maintenance forum from a few weeks ago. Someone posted the technical service bulletin regarding this issue. Seems that you will either need a software update or new computer depending upon the build date.

Had the exact same thing happen to me. Quite a scare.

I borrowed this from another site. Its from a technical service bulletin:

Speedometer Erratic Movement, Fuel Gauge Does Not Go to Full After Filling, Engine Coolant Temperature Gauge Reads Hot and Coolant Temperature Light Illuminates (Reprogram IPC) #05-08-49-003 - (Jan 20, 2005)
Speedometer Erratic Movement, Fuel Gauge Does Not Go to Full After Filling, Engine Coolant Temperature Gauge Reads Hot and Coolant Temperature Light Illuminates (Reprogram IPC)
2004 Pontiac GTO

Built Prior to VIN Breakpoint 4L29601

Condition
Some customers may comment on one or more of the following conditions:

• Speedometer jumps erratically. Gauge may go up to 200 MPH or not return to zero.

• Fuel gauge does not move off empty when tank is full.

• Engine coolant temperature gauge reads hot and coolant temperature light illuminates.

These conditions may be intermittent.

Correction
Technicians are to reprogram the IPC with an updated software calibration. This new service calibration was released with TIS satellite data update version 1.0 available January 10, 2005. As always, make sure your Tech 2® is updated with the latest software version.

Important: Vehicles built after the VIN breakpoint must have the IPC replaced to correct these conditions.

I nearly shat myself when it happened to me. I took it to my technician here in CA, but he said there was no problem. I'm taking it in again after this though.

Had the same thing happen to me. Also I noticed something else this week end. I let a friend of mine try out my car and he decided to double clutch it. The tac went to 6500RPM by time the next gear caught. What happend to my rev limiter??

Anyone else notice this after their temp and gas guage malfunctions?

So, 131NC, would that be North Carolina Hwy 131???

Flash, I've had the temp and gas guage problems as well as the speedo & tach gremlin attack, but not all at once. Also had the brake warning display act up once. Right now I'm playing hide & seek with the idiot light that tells you your lights are on. Sometimes it works, sometimes its off to happy hour.......
The service manager at the dealership is lost.

I'm in NC, near Charlotte. 131 is my call number(I'm a police officer). Originally from Buffalo NY. My wife and I were back up there last month, weather was terrible. Saw one '04 GTO up there, driving in the snow and salt slop. I love sunny NC!