New 2006 Outback Sport Impreza, 2.5 liter engine, 5 speed manual trans. Nice care but has an odd characteristic that is driving me crazy.

 

Car is fine when accelerating or decelerating. But any time you are just attempting to hold a certain speed, backing off on the gas pedal and just keeping the speed the same, you get a sensation that someone is tapping on the brakes, or that the car is slowing and then speeding up. It feels like a constant bucking back and forth. Not violently, but subtle yet definite. Others have driven the car and they can feel it too. So can passengers.

 

When the AC unit is on, it's much worse.

 

I did take it back to the dealer and they said nothing was wrong with the car. Their "technician" said it was just a super sensitive electronic throttle and that you have to take your foot completely off the gas pedel unless you are actually accelerating. Said I would get used to it. I haven't.

 

Any ideas?

 

One last thing that may or may not be related - when you first start this car up in the morning, everything is fine until you put it in gear and let the clutch out the first time - you have better be ready to push the clutch back in quickly, because the engine is going to self rev to about 3500 RPM. It does this for about 10 seconds, then settles down and is fine for the rest of the day. But every morning, first time you put it in gear and let the clutch out, it revs to 3500 RPM all on its own. If you don't get the clutch back in you'll take off like a bat out of ..........

 

Any ideas on that?

 

Thanks to all. Nice car but these two things are very annoying.

One last thing that may or may not be related - when you first start this car up in the morning, everything is fine until you put it in gear and let the clutch out the first time - you have better be ready to push the clutch back in quickly, because the engine is going to self rev to about 3500 RPM. It does this for about 10 seconds, then settles down and is fine for the rest of the day. But every morning, first time you put it in gear and let the clutch out, it revs to 3500 RPM all on its own. If you don't get the clutch back in you'll take off like a bat out of ..........

 

Any ideas on that?

 

Tom

There is a ECM update for your last concern . It may fix the first concern

 

SEA#3

 

Thanks to all. Nice car but these two things are very annoying.

Years ago my father had a Chrysler New Yorker that had the same herk and jerk with the cruise control, and it was a new car. What was traced down was that the cable to the throttle valve from the cruise control actuator was too tight. It didn't have enough slack, causing the cruise control to hunt up and down with the throttle in jerking motions. Once a little slack was introduced into the cable, by backing off the locking nut on the cable assembly and retightening the nut on the other side of its mounting bracket, I believe it only needed one or two turns of each nut, the problem was solved. I realize that this was on a 1969 automobile, but some things haven't changed in 35 years. Its worth a try, will take two minutes to do before a test drive, and if it doesn't solve your problem will still only take two minutes to put back. Good Luck!

[...]What was traced down was that the cable to the throttle valve from the cruise control actuator was too tight.[...]

Good general info, but does it apply to the newer Subarus that are "drive by wire"?

I had a Lumina:rolleyes: that did that sort of thing. It definately had a hitch-up in it's getalong but only during low throttle cruising situations like you describe. After some looking and cursing I pulled the plugs just on a hunch. One of them was missing the little nipple thing from the outside electrode that used to be there. This effectively almost doubled the gap and was causing a fairly consistent misfire on that cylinder. I was trying to sell the car so I just regapped it without the nipply part and it ran perfect again.:cool:

Actually, the car runs smooth as silk when using the cruise control, or accelerating, or decelerating. But if you try to keep it at any constant speed you get the buck, surge, brake, lag, buck, surge, lag, brake, feeling.

 

I suspect it has to do with the drive by wire electronic throttle since you can stop all the bucking and jerking just by taking your foot completely off and away from the gas pedal.

 

Would still like to reset the ECU just to see if that makes any difference. How would one go about doing that?