Ok, so I got off the highway to day, and glanced down at my gauges to see I was doing 75 around a 25mph curve, thought it felt fast, but not that fast.

Anyway, when I break, it slides down about 5 mph, and when I accelerate, it moves up to reflect a gain of whatever i actually picked up from where i just was. Right now I'm parked in the drive way doing 128.

Any thoughts?

 

https://montecarloforum.com/m_62459/mpage_1/key_/tm.htm

let us know if that works for u!

 

This is a common problem with the 6th generation Montes. The guages tend to go bad. If you have any kind of warranty left, it's covered. Basically the dealership will replace the entire guage cluster. The old one has to be sent back or there's a core charge. At least that's what they told me. So if you have custom mods done to your guage cluster, you should remove them before bringing the car in.

I had that problem happen to me with my Temp guage. I suddenly looked down and saw my Temp guage look like this:
(I had my camera in the car at the time)




It scared the crap out of me since I was out in the middle of nowhere on a rural road at the time. But I looked at the message display in the tach, and there was no message. Luckily I remembered hearing about this problem from others on this site. I re-started the car, and the guage then went even higher and looked like this pic (which I thought was funny):

 

Well, the key thing has worked for now, I'll keep an eye on it and see if it acts up again.

If I end up replacing the cluster, will it show correct mileage or is that stored somewhere on the cluster and not on some other computer module?

 

The odometer will remain the same. I didn't get too detailed into if it was stored in the gauge cluster or if it was programmed back in. I believe it is in a separate unit though.

I had a pic that I brought to the dealership though where I was outside of the car, rpms where at 800 and the speedometer read 130 mph.

 

800 rpms at 130? wow dan what could u possibly have done to your engine? lol

 

After re-starting mine about 6 ot 7 times, the temp guage seemed to start working normal again. But I had it replaced anyway because I didn't trust it anymore. It already messed up once. Who's to say next time my engine really will be overheating and I won't know until it's too late because the guage is stuck in the "normal" zone? Besides, I paid for the extended warranty, I might as well let it start paying for itself.

In your case, if you have to pay for it out of your pocket, you can fix it as funds permit. Not sure if they'll let you buy just the one guage or not. But I do know of someone who purchased a new guage cluster and kept the old one. Claims he took apart the faulty guage and fixed it. I believe he's trying to sell the repaired guage cluster on ebay now.