When I'm driving mostly around 45 or more up a hill or flat ground it vibrates and kinda shakes but when I put it in 3rd from OD it drives fine. Something wrong with my over drive? I'm going to flush system new filter and fluid. But I don't know if it will help. Got 133000 on it Thanks for your input

 

Depends on which rear end ratio your car came with--Stock is a 2.73 and an option was the sport ratio of a 3.15---You can go to your rear end and there should be a tag marked with your rear end ratio
If your car has a 2.73 and it has never been tuned----GM locks the converter in 4th gear at 38 MPH----This is horrible and causes bucking and surging at low speeds---Tuning will be the best thing you can doo to a car with 2.73 gears beyond an actual gear change----Best is to have it tuned so the converter does not lock til about 50 MPH or approaching freeway speeds- Also raising all the P/T shift points by 2-3 MPH will prevent the car from lugging all the time and short shifting and becoming not fun to drive around town-----This keeps the RPM's up between shifts and at lock up in 4th gear
This is common with all C5's with a 2.73 rear ens--I doubt if there is anything wrong with your trans----mechanically

 

You SHOULD be able to BOG the engine and it should NOT SHAKE or MISFIRE.

You description on what is actually happening is kind of vague.

When you experience the shaking/vibration, do you see any of the following???

FLASHING CHECK ENGINE LIGHT (CEL)

If you use the DIC and check the Diagnostic Trouble Codes what DTCs pop up? I will provide you the procedure to read the DTCs from the dash. If you have TONS of old DTCs, CLEAR ALL OF THEM!

Take the car for a drive and make it do the shake/vibration. When it does it, look at the IPC and see if the CEL is flashing (engine is misfiring) and read the DTC (BEFORE YOU TURN THE IGNITION OFF) and see if you get a PCM P-0300 (misfire DTC)




READING YOUR Engine Diagnostic Codes


The Diagnostic Display Mode is entered with the following procedure:

1) Turn on the ignition but don't start the engine. NOTE! You can read the DTCs with the engine running and or driving down the road but it can distract you. BE careful! Some DTCs clear themselves when you turn the ignition OFF!

2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open ect)
3) Press and hold OPTIONS
4) While holding OPTIONS, press FUEL four times within a 10-second period.


Initially, on-board diagnostics go into an Automatic Mode which shows diagnostic codes in a pre-set sequence: PCM - TCS - RTD - BCM - IPC - RADIO - HVAC - LDCM - RDCM - SCM - RFA. All codes will be displayed for each. ( i.e. PCM = 4 codes) If none are present in a given module, you will see No More Codes on the display.
There are two kinds of diagnostic codes, Current and History designated with a letter suffix, “C” or “H”. A current C code indicates a malfunction is present and active in the module displaying data. A history code indicates a problem existed sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it's potential evidence of a previous problem, now resolved, that was not removed by clearing the codes.
More likely it's an indication of an intermittent malfunction.
Intermittent codes are the most challenging of the diagnostics. An intermittent code may have happened once, may have happened more than once but is inconsistent or may be happening on a regular basis but not at the time the codes are displayed. History codes can also be caused by a current malfunction in a system that is not operating at the time codes are displayed. An example is the rear window defogger which doesn't operate until the Body Control Module detects engine rpm. For history codes set by a module that does not operate with the key on and engine off, a special diagnostic tool called a Scan Tester is necessary to properly diagnose the malfunction.
Once the system has displayed all modules, it goes into the manual mode which allows selection of each module using combinations of Driver Information Center buttons. Manual mode can also be entered during the automatic sequence by pressing any button except English/Metric (E/M). Once the display shows Manual Diagnostics, select a module by pressing the OPTIONS button to go forward or the TRIP button to go back. Once a module is selected, a code is displayed, and if more than one are present; press GAGES to go forward or FUEL to go back.
To exit the diagnostic mode at any time, press E/M. If you want to erase codes in a given module, press and hold the RESET button To reset the codes once in manual mode, press and hold RESET until it displays NO CODES Press OPTIONS to go to the next module. Repeat the steps until you have reset the codes in all the computer modules.
NOTE!! Only reset the codes IF you want to - it is NOT necessary to do this. Clearing a code does not repair a problem. You are simply erasing the evidence of it in the module's memory. If you clear the code/s, and extinguish the Check Engine Light, your emissions status ready will NOT allow you to pass an emissions test until you have completed the required driving cycles.
Once you have the codes, the next question is: What to do with the information?
First, consult the factory service manual. Any serious C5 Do-It-Yourself owner should invest in the Corvette Service Manual of the appropriate model year. The Service Manual is really a requirement if you want to understand and work on your C5. You can GOOGLE the DTC and also find information on it.




Here is very good site that explains the DTCs:


http://www.corvette-web-central.com/C5DTCcode.html


http://www.corvette-web-central.com/C5DTCcode.html


http://www.obd-codes.com/trouble_cod...d-ii-codes.php



Make sure to include the H or C suffix!!

 

No . No codes no lights nothing. From what I think and found out it might be the torque converter. So I'm going to get it looked at