bayoukid

Hello, I'm a new member and am not sure if this is where this needs to be.
I have a 2011 Silverado crew cab 1500 4.8 ci v8 engine. This weekend the family and I went camping with the 25' EVO Forest River travel trailer. We started out at an elevation of 450.ft. and drove up to an elevation of 4400 ft.
During our climb all at speeds of around 45-50 mph. the engine was working great, the trailer mode was engaged and all was fine. Then, at one point in the climb I noticed that we were loosing speed as the road rose to a seep point in the trip.I pressed on the accelerator and the tranny kicked into passing gear the tach rose to about 4500 rpm then all of a sudden it pegged! 6000 rpm, however the engine and tranny was working normal all the normal sounds. Of course I immediately let go of the accelerator and pulled over stopped and shut the engine off. The tach stayed at 4500 rpm with the engine off. I re started the engine and it went back to 6000 but the motor was running normal.
I took off again and it went all the way to the bottom the gauge. it stayed there till we arrived at the camp site. I set up camp and went back to look at the tach, it was still at 4000 rpm. The next morning I looked and it was down to 1500 rpm. Remember this is all with the engine off. I pulled the tach fuse it was OK but seemed to reset it to 0. I have never experience anything like this and no one I talk to has either. The drive home was normal. So has anyone out there ever experienced anything like this on their truck?
Sorry for the long story.

89scottsdale

Well judging by your story your tranny isnt shot! (thank your lucky stars)

If the Gauge sticks while the engine is off, and the ignition is off, this is a good sign that the stepper motor has gone faulty in the cluster, or something is stuck inside the assembly. if the cluster is on, the gauge sticks, but moves when everything is shut off, you might have a glitch or faulty sensor.. ETC.

Things i would try:

Pull the Postive and Negative cables off the battery and wait for 10 minutes. if that doesnt change anything pull the connectors again and touch them for 30 seconds, then reconnect your battery. Beware this resets the WHOLE truck, Such as Adaptive shift points, presets, ETC. restart and test drive.

If that doesnt work, you may have a faulty speed sensor, Cluster, bad ground, Something of the sort. take it to a dealer or shop and get it scanned. Im convinced its a cluster or glitch since the speed determines MANY MANY things on the operation and efficiency on these trucks.

Sage

bayoukid

89scottsdale,
Thanks for the input, I was thinking along the same lines as it being the cluster. I will look into the reset, however I need to do some homework first as I need to be assured that the reset will allow me to drive without issue the next day to work. It only happened that one time. I've driven it since and all is normal. However that was the first time I pulled the trailer to that high of an elevation with this truck. Hmmm, and I remeber them saying that computers will make our lives easier. Great salesman they were.LOL.

89scottsdale

If its fine now, just unplug the battery for a while and plug it back in. sometimes glitches happen, and its crazy how they fix themselves. one day the "service airbags" light came on in my 2003 Silverado, Expecting a hefty bill, I was told to Kick the panel below the emergency brake and if that didnt work just take the panel out and unplug-replug in the wires. i just kicked the panel and the codes instantly went away and that was a year ago!

good luck!

sage