2005 Buick Park Ave Odometer reads about twice as fast as actual speed. Looking back went from 150K mi to 195K mi in two years. But only drive about 10 mi per week + a couple 180 mi weekend trips. Any ideas?

if your refering to the light on the odometer and its dark there is a little resister on the back of the cluster that you cannot fix yourself unless your an electronic oriented person. this happened to me. I went on ebay and bought another one and it worked about 2 years and not its the same thing, black with no light. I read some where these are warranteed for life by buick and they have to replace them but that was around 8 years ago and not sure if it still applys.

Usually if the speedometer works but the odometer does not, the problem is inside the speedo assembly. It would need to be sent to a shop for repair or replaced with a used assembly.

use a code reader to reset the CPU.

I have had the almost same problem twice. A 'thump', like the engine missed a fire and tach drops. Seems OK after restart. Electrical? Timing chain slip?
Has 135,000 mile. Any clues?

Sounds like you have another Vacum Leak, What is this thing idleing speed AT...?????? Vacum Leak Cause high Fast Idel...so i would check futher into more leaks

warning light activates when it senses low fluid lvls. chk your brake fluid then chk for leaks.

You may have damaged the starter when the engine kicked back.

The ignition module may have been defective.....but change the crank pickup too.........more likely it is the cause of the problems.

Change the crank pickup at every tune up..........it has a high failure rate.

If your engine has 250km or 150K miles you may need a chain soon.

MAN U SHOULD GIVE ME THE ERROR CODE

You probably got a spike when disconnecting the cables from the battery...the other thing that might have spared this problem was to take the battery cables off while charging.

Speedometer or fuel gage?

If speedometer which is bouncing around, it is likely a bad ground near where the speed sensor wire harness (which connects the speed sensor to the rest of the "network") exits the transmission housing. It's at the very back of the transmission (you have a 4T60E trans) to the left of where the right side half-shaft leaves the trans housing. Just look for damaged wires. If none, replace the speed sensor for $50-60.

If it is the fuel gage, the sensor is probably not "zeroed"--it's reading wrong, too high, and if it were to start at true "empty", it would read right. Thus, the gage is always reading a little high (maybe a 1/8-1/10th of a tank too high?). This isn't a problem until to stop, start, or turn quickly and cause the fule to slosh around in the tank and starve the in-tank pickup which sends fuel to the engine.

If it is the fuel gage, you should simply put as much fuel in as you can and see if the needle goes far above "F". If it does, note how far it went and then practice filling the tank when the needle is that same distance above "E".

Hope this helps.