2010 Cobalt issue

[bensonwe]

Good morning. Needs some help. My 2010 Cobalt is having shift issues. Between 30 & 50 mph and between about 1200 & 1800 rpm's the rpms randomly increase about 500 rpms and then settle back to normal. This happens while im excelerating normal or just normal cruise. It does not seem to do any of this under heavy excelertion. Any thoughts would be appreciated. Thanks

[Rich/WIS]

Have you checked your transmission fluid level? Don't know if you can on some of the newer cars but had a similar problem on a 2009 Jeep and issue was fluid level. Some newer cars don't have the old dipstick and almost have to go to a dealer, my Jeep was like this. You're reaching ten years on the car and the cost of a trip to the dealer and a flush and fill is still less than blowing a transmission. I am not a mechanic and hopefully someone who is will chime in shortly.

[Frosty Boolit]

Maybe related to torque converter clutch lockup. My dad had a Chevy that would unlock the TC clutch every time the ECM detected a cylinder misfire.

[edp2k]

This sounds exactly like the throttle position sensor is bad/going/worn.
its a small electrical device on your fuel injection throttle body.
Word of advice: get a replacement one from a chevy dealer and not from the local autoparts store.
the parts store will sell you a cheap version which will fail in a few weeks, and may fail in a much more spectacular way than
your old one, if you catch my drift.

[Lloyd Smale]

my thoughts. Either that or your clutches are worn out.
Maybe related to torque converter clutch lockup. My dad had a Chevy that would unlock the TC clutch every time the ECM detected a cylinder misfire.

[jonp]

Are you getting a check engine light? My CR-V is doing the same thing. Check the voltage on the throttle position sensor. Replace the trans fluid and filter and make sure it's the correct level. Check all wiring and connections. It might be the torque converter which means a tran rebuild or new/used transmission.

My 1997 CRV seems to be the converter. No filter to change in the trans.I replaced the TPS, changed the fluid and added some Lucas to try and get a few thousand more miles out of it before deciding what to do. At 180,000 I don't think $3,000 for a transmission is in the future, probably sell it for $500 to someone that wants to mess with it

[bensonwe]

No check engine light. Checked the tps but seems to be in spec. With it having issues in that very specific range i was really expecting it to be the tps. Other forums say it may be the shift solenoid but have to remove alot of parts to get to it. Thats going to take more than a night after work. Thanks all for the input.

[Pressman]

My 1999 Dodge diesel was doing that, turned out the wire from the computer to the transmission was laying on the alternator and getting RF interference. Moved the wire and all was well.