Subaru WRX - high, increasing revs when idle in traffic

Hi

My car is a 2005 Subaru WRX Sedan. It has 37000 miles and has had all the regular servicing.

Last night I did some highway driving (25mins) and then was in city center stop/go traffic. After about 10 mins in the congestion the revs started to increase when idling (clutch disengaged and in neutral). Typically it sits at about 600rpm or so when idling, it was started out at 1500rpm. After another 5 minutes it had passed 2000 rpm, another 5 and it was close to 2750rpm. Felt as if I was holding the accelerator down constantly. I didn't have any engine management or oil lights showing on the dash, and temperature wasn't any higher than normal.

Only thing that reduced the revs was to put the car into 1st or 2nd gears and engage the clutch. Doing this made the car feel like an automatic - no need to put my foot on the gas. I've probably done some damage to my clutch, but wasn't sure of possible damage from the high and increasing revs.

I found somewhere to get my car pulled over and I turned off for

15mins or so. When I started it up, revs seemed normal again, and I was able to get the car to my mechanic since I was near the highway. On the highway driving the car performed as it had done earlier.

I've left the vehicle with my mechanic now, and am expecting a big bill! Anyone have any thoughts on this, or experience anything similar?

-Brian

Reply to
Brian
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I am not sure about the WRX, but the STi has electronic throttle control (drive by wire). If the WRX does, itcould just be a bad sensor. If not, it can either be an 02 sensor or something wrong with the ECU. If it is the ECU,it can be expensive. If it a sensor, it probably won't be too bad

Reply to
JD

Does the wrx or sti have an egr implemented?

Reply to
bgd

I get this from my insurance website and it has it listed for my 03 WRX. Not sure if it specific to the WRX. but may want to look into it.

VEHICLE SPEED CONTROL:CABLES

Recall Number: 04V128000 Dates Manufactured: SEP 2000 to FEB 2004 Number of Vehicles Affected: 127580 Date Owners Notified On: Unavailable ON CERTAIN PASSENGER SEDANS, WAGONS, AND SPORT UTILITY VEHICLES, THE CRUISE CONTROL CABLE COULD COME OUT OF ITS TRACK ON THE CRUISE CONTROL LEVER AND LODGE ON THE CONTROL LEVER TAB WHEN THE ACCELERATOR PEDAL IS RELEASED. IF THIS CONDITION OCCURS, THE THROTTLE WILL NOT RETURN TO THE IDLE POSITION AND WILL REMAIN IN AN OPEN POSITION.

Reply to
Mike

My 2005 Forester XS did the same with me twice. Then I figured out my foot was pressing the brake pedal, and would overlap the accelerator. So the harder I applied the brake, the higher the revs.

I have now gotten use to the small distance between them, and now at 37000 miles, it doesn't happen much.

If this is not the case, then as others have posted, it is most likely the TPS (throttle position sensor) for the throttle by wire system. I am wondering what their life span will be, and I try to use cruise control as much as possible.

Blair

Reply to
Blair Baucom

Odd you should mention this. My base Impreza (2007, 2.5i with manual transmission) was revving very high one morning (3,500 rpm at a stop light). revving it "up" to kick the idle "down" (like you do in older, carb'ed cars), did nothing but increase the idle. My car was at ~4000 when I shut the engine off, put the 4-way hazards on, and popped the hood. No throttle control cable anywhere. It's drive by wire. I fired it up, problem went away. I moved the floor mats back just in case (away from the pedals).

1200 km's and it's ok so far. Stoneman
Reply to
Stoneman

Thanks for the replies. The throttle control valve/sensor had a lot of carbon according to my mechanic. He tried to do some diags on the computer but it had been reset. No idea how this happened as I have never had battery/power problems. He'll have the part tomorrow and I'm going to drive it for a week to test the computer.

-Brian

Reply to
Brian

It never hurts (well, not that I can think of) to remove the negative battery cable for a few minutes. I used to have a 98 ford expedition that one time started having similar symptoms. A reset of the ecu or whatever by way of removing the battery cable fixed me right up, never had the problem again.

--Dan

Reply to
dg

At the risk of stating the obvious, make sure the engine is *not* running when you do this. Load dump is a bad thing for automotive electronics.

Reply to
Jim Stewart

I have a 2003 wrx I am having the exact same problem too. its getting worse every year since i owned it. the only time i notice the cooling fans coming on is when i have the defroster on or the ac. If you noticed under the hood when it is revving it is really hot. i think it is revving to keep the coolent flowing to keep it cool. If you find out what the problem is with yours could you let me know too

"Brian" wrote: > Hi > > My car is a 2005 Subaru WRX Sedan. It has 37000 miles and has > had all > the regular servicing. > > Last night I did some highway driving (25mins) and then was in > city > center stop/go traffic. After about 10 mins in the congestion > the revs > started to increase when idling (clutch disengaged and in > neutral). > Typically it sits at about 600rpm or so when idling, it was > started > out at 1500rpm. After another 5 minutes it had passed 2000 > rpm, > another 5 and it was close to 2750rpm. Felt as if I was > holding the > accelerator down constantly. I didn't have any engine > management or > oil lights showing on the dash, and temperature wasn't any > higher than > normal. > > Only thing that reduced the revs was to put the car into 1st > or 2nd > gears and engage the clutch. Doing this made the car feel like > an > automatic - no need to put my foot on the gas. I've probably > done some > damage to my clutch, but wasn't sure of possible damage from > the high > and increasing revs. > > I found somewhere to get my car pulled over and I turned off > for > 15mins or so. When I started it up, revs seemed normal again, > and I > was able to get the car to my mechanic since I was near the > highway. > On the highway driving the car performed as it had done > earlier. > > I've left the vehicle with my mechanic now, and am expecting a > big > bill! Anyone have any thoughts on this, or experience anything > similar? > > -Brian

Reply to
m

Mine does the opposite. My 03 will idle fine then dip. Sometimes it feels like is about to stall. I'm going to try cleaning out the IAC valve, probably should change my pcv valve too. I know its not time but i may pull my plugs and see what they look like. I dont have a CEL.

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Reply to
Mike

replying to Stoneman, Steve Hirsch wrote: Did the problem return? Any idea what caused it?

Reply to
Steve Hirsch

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