Mystery vibration or shimmy?

[marvinmoon]

I just got a '97 Grand Caravan and drove from Va to AZ ..intermittenly I got a shimy or vibration that kind of felt like tires or frontend, but with immediate gas reduction it stopped? Usually about 65 MPh and seemed like fuel statrvation then with release slightly and reapply of pedal it was fine?
Any suggestions of anyone expereinced this and how I should proceed?
Thanks in advance ......... Old and white hair not used to "these new fangeld things"
Had first car Dodge 1958 Custom Royal w/push button trans ...Loved it while in the Matrines 1960 on ..... then got Dad's ole truck pickup "59 D-100 w/swept wings... restored it ... Truck steering wheel/ hydraulic clutch/radio in roof ...first attempt at Camino competition by Dodge .. Divorce forced me to sell ...Darn!!

[CBP ENGINEER]

It could be tires being out of balance. Check the tires for abnormal wear, you might have to get an alignment or the tires balanced. Vibrations can become noticable at certain speeds and not at others, that is why letting off the gas will make it seem to go away.

You also mentioned fuel starvation. Since the vehical is new to you, you might want to take it to a place like Auto Zone and ask them to check the van's computer for error codes. Some places like Auto Zone will do this for free. If you get error codes, write them down and get back to us to help track down the problem.

[marvinmoon]

I did get a code of PO740 which came up as Torque Converter Clutch Circuit? Don't know if that means electrical or tranny w torque replace or work?
Thanks for your comback and help . Ny advice? :help: I will bal and align frontend

[gas28man]

Despite the code, I'm still inclined to believe your shimmy is in the tires. If it shakes or rocks the steering wheel in your hands, it's a front wheel. If you feel it more in the seat of your pants, it's a rear wheel. Worst-case scenario, I have known a front end vibration to be caused by a failing CV axle, and with just the symptoms you describe (i.e. the vibration is worst when you're on the gas, and practically nonexistent when you let off the gas).

Now, as to your code, it does suggest an electrical glitch, but just to be on the safe side, it might be worth the $75-$100 to go get your tranny fluid flushed (including a torque converter flush) and the filter changed. Since you say you just got the van, you need to know that these vehicles are very sensitive about tranny fluid. Despite what the owner's manual says, I would never let one go more than 50,000 miles between changes. And you must always use ATF+3 or ATF+4 without fail or you'll wreck the transmission in a hurry. Unless you've got documentation from the past owner that tells when the fluid was changed last, I would assume the maintenance wasn't done and get on it.

Once you get the fluid change done, you can clear the code by unhooking the negative battery cable for five minutes and reinstalling it.

If the code comes back, take it to a trusted shop to have them check your solenoid pack and transmission control module.

Good luck, and let us know what happens.

Rick

[marvinmoon]

Thanks for all the help I appreciate it very much and will follow it! I'll let you know ....