mlentz

With my 2004 impala the speedometer will work fine after driving for about 20 minutes. Then it will go way up to 110 and back down to 60 then stick at like 70 until I pull over and turn the key off and on enough for it to go back to zero. Sometimes this will fix it for a while and sometimes it won't. Any ideas?

higgsboson02

The problem with your speedometer may be a bad electronic cluster in your gauges. Had a similar problem with the oil and temp levels. If under warrenty, take it to the dealer and should be covered for the replacement part. Part may be order directly from Chevrolet. If not covered, parts and labor will run you around 300.

redly1

If you're not picky about which display you get (i.e base model w/no tach) you can get an instrument cluster for ~$50 off ebay


search "impala cluster"

samahi72

let me know what you did to fix yours. My father in laws 2004 is doing the exact same thing. Out of warranty of course and GM won't do a thing, and they wonder why people are buying foreign.

Iflylow

These cluster problems are very common. Email a guy named BBEngineer@comcast.net. He rebuilds and modifies clusters, and can get you one fairly cheap. By the way, here is how to get your cluster out:http://impalahq.naioa.com/ Look under "How To:" and then "How to remove the instrument cluster trim plate"
If you buy a cluster off ebay, be aware that it will not display the correct mileage. Mileage is stored on the cluster itself, and the cluster must be taken apart to reprogram it. Also, just because a cluster will fit in your car does not mean it will work right. Some years and models will only work with certain other years and models.

Tom-ADC

We had the same problem with our 2004 not only the speedometer but all the gages went wild. I was able to get it repaired under a "Good Will Warranty repair" the actual cost would have been $562 for a exchange cluster. Dealer tells me problem is very common with the trucks but not as bad with the cars.
I figure I got lucky getting it fixed this way. Good luck

chevyp2p

I had the same problem in my car. I found a website where I had my cluster rebuild for $140. That's a lot cheaper than the $750 that the dealer wanted to replace the speedometer.
Here is the address incase you wanna check it out:
www.speedometergaugerepair.com

denco

My 2004 has the same intermittent speedometer problem.
I want to repair it now, but remember reading somewhere that if you remove the cluster, the car may not run.
Can you drive it with cluster removed?

HeMi101

Yes you can drive the car without it.

__________________

Dave_R

Another thing to check is to make sure the alternator connections are tight, along with the battery connections (sepecially the GROUND for the battery).
On my Lumina (Similar to the Impala) I had a bad ground connection on the battery cable.
This caused a LOT of AC ripple from the alternator to affect the speedometer pulses from the speed sensor. This "fooled" the speedometer by displaying erratically high speeds (it would jump up between max and around 60 MPH when barely moving).

Cleaning up the ground connections for the battery cables fixed it.

----Just a thought of another possibility

SierraK1500

OK Folks heres the deal and the fix for your car.

Several previous posters all hit the problem. BUT This is the fix.

I have a 2005 Impala that had the same bad speedo. I turned the key off and on several times to get it back to zero.

There is a servo motor in the cluster. This motor runs on impulses from the
unit on the Transmission and a few other places in the car. The bearings in the servo motor DO AND THEY WILL GO BAD. There is no ready available solution for these bearings in the motor but to replace the entire cluster.

If you get a USED cluster from a junk yard it will not have the same mileage as the one in your car. It must be reprogrammed with the current mileage. Make sure you get a cluster from the year your car was made to insure that it will work and fit properly. DISCONNECT THE BATTERY!!!!!

If you go to a DEALER look to spend 500.00 to replace it. I have had it replaced with a new one.

In any case if you replace the cluster and all the connections are made and the unit is reinstalled in the dash, reconnect the battery and leave the key ON for 20-30 minutes. Try to start the car. The security light may come on and the vehicle will not crank. If the car does not start after you tried to reprogram the new cluster and the BCM do it again. It should start after.

If you have a Garmin or other GPS device with a speedo attached, your speedo cluster you installed should be accurate, or +- 1 mph.

If you have any questions feel free to send me a personal message.

John

shadetreewannabe

I had the same problem on my 2004 impala ss.I ordered the new servos off ebay and soldered them in it is not very hard.That was 2yrs ago at 39000 miles now at 62000 no problems.Do not put a used cluster in or you will have the same problem,GM had a bad batch of servos.

denco

Is their a part number on the servos?
If I could order the servos, I would have no problem with desoldering and replacement.
Do they have to be calibrated?