When i travel anywhere around 40 mph my RPM will jump up about 100 and then back down. It will go up 100 for about half a second and then drop back down for around a second or 2,and continue until i'm driving faster/slower. you can feel and hear the change in revolutions. At idle its fine, needle doesn't move a bit. It's also fine at highway speeds. It only does it at the cruising speeds on the streets around town, 35-45 mph range. No check engine light or anything.

This is an 05 automatic with about 54k miles. I've only had it a few months. i seafomed the gas and intake a couple days after i got the car, i can't remember if it did it before that. That was about 1000 miles ago.

Any ideas?

 

Mine does the exact same thing...from 1500 rpm it jumps to about 1700 ish then back down to 1500. Only in that spot...setting cruise control makes it stop, but if I hold it there with the pedal it will do it every time. I usually just down shift a gear to make it stop untill I can get over 40 mph.

 

I have an 05 with 54k and I've seen this a few times since I've had the car....usually it shows up at ~35-40 mph..RPM starts jumping 100-200 rpm while speed is constant. I just speed up or slow down and it usually goes away...

 

OP...anything new?

 

perhaps torque convertor lock up?

 

Ha, and I thought it was just my car. Makes me feel better anyway.

I just wrote it off as being near a shift point (not saying it is or is not, that's just what I assumed). I just speed up a wee bit and it behaves.

I don't recall exactly where it happens, but I know it's around 45 mph.

 

This actually happens in 4th gear and 5th gear for me. Both instances seem to show up around 1400-1600 rpm. For some reason it seems to happen more often as its been getting colder outside.

Whenever the rpms start to dance it seems like I can maintain my speed (ie. it doesn't effect the speed of the car..just the speed of the engine). Would it be a tranny problem if the car seems to maintain speed but the engine speed increases?

 

It's hunting. Really.

 

Mine is doing the same thing in the cold weather when I had bought the car in August it was fine but now with weather being cold the rpm does sorta bounce but not really to bad just maybe 50 to 100 rpm at around 47 to 48 mph

 

Somebody solved this problem? I have the same problem with my car... Unfortunately...

 

I had similar problems with my 05 TL an it was the throttle position sensor

 

I am having the same issue with my 10 TL. Wanted to search it here before i called up my dealership.

 

Welcome to the forums.

You should post this in the 4G TL Forum. https://acurazine.com/forums/4g-tl-problems-fixes-297/

I would move this for you but sometimes newcomers have a hard time finding a post that has been moved.

 

mine does it and i took it to the dealer bc i couldnt figure it out, they didnt come back with any diagnosis.

 

I've never noticed this before, but I will now. Kind of wish I would've never seen this thread.

 

Yep, it's kinda on the bubble, does'nt quite know what you want to do, speed up a little, then set the cruise.