When I leave work and it is cold out, say around 35=40 the car jerks bad. It usually runs for about a minute before I leave the parking lot. It's not like I'm taking off hard at all, don't want to stress a cold engine, just an easy pull. If I take off at a more moderate rate it feels just as bad. The jerkiness raises with rpm's. Feels like there is a patch of super glue on the tires. Once the temp guage starts to move, the jerkiness starts to dissapate, as soon as the temp guage gets to 1/4 on the first mark it is fine. I live about 100 yards down a gravel road so I idle to the hwy, by then the car has warmed up enough it doesn't do it. It is hard for me to take it to the dealer as the nearest one is 3 hours away.

When I leave work and it is cold out, say around 35=40 the car jerks bad. It usually runs for about a minute before I leave the parking lot. It's not like I'm taking off hard at all, don't want to stress a cold engine, just an easy pull. If I take off at a more moderate rate it feels just as bad. The jerkiness raises with rpm's. Feels like there is a patch of super glue on the tires. Once the temp guage starts to move, the jerkiness starts to dissapate, as soon as the temp guage gets to 1/4 on the first mark it is fine. I live about 100 yards down a gravel road so I idle to the hwy, by then the car has warmed up enough it doesn't do it. It is hard for me to take it to the dealer as the nearest one is 3 hours away.
Is this other than normal "trailer-hitching"? This is the only explanation I've been able to come up with so far: When the motor is warming up, idle speed is pushed up as far as 1500 RPM to start. That means when you engage a gear, the motor slows down, while the ECU is trying to push it up. Meanwhile, you are trying to push it up gently, and while you ease slightly off the pedal and the car begins to coast, the ECU is still pushing it up again and it begins to surge, and there is a little back and forth micro-struggle between you and the program as you try to keep easing and it tries to keep surging. It is frustrating, because you can feel the driveline whipping itself back and forth and making you feel like great, just try to avoid undue wear and tear and the driveline and see what you get. The best treatment I've found so far is to not particularly baby the throttle just starting off. Push it down and don't be hesitant when you shift into second either. The second best treatment I've found is to keep my foot off the gas and just let the car pick up the clutch from first and do what it wants, and then move possibly into third, again without putting on any gas. Once the idle speed gets down to 1000 RPM and below, it is easier to shift normally.

I'm glad to hear I'm not the only one with this problem! Ha one more Quirk of the Subaru. :devil:

"trailer hitching" I'm not sure that is it. It does it all the way up the rpm range till I shift and then in the next gear. This goes on for about two blocks, just till some heat gets built up in the car. Don't know if it will do it all the way to red line cause I usually shift between 2-3k. As far as a micro struggle, it's bad enough if you had a cup of coffee it would get spilled all over the place. It is definately related to the car being cold, as soon as the temp guage starts to climb, it's gone. I assume it's in the motor, but I have not ruled out the tranny, although it seems more related to engine rpm than wheel speed. I just hate to take the car to the dealer, 3 hr drive, knowing I'll be driving a rental turd for a week, if, they can duplicate the problem.

Feels kind of like my wheels are shaped like eggs, a very eneven acceleration.

"trailer hitching" I'm not sure that is it. It does it all the way up the rpm range till I shift and then in the next gear. This goes on for about two blocks, just till some heat gets built up in the car. Don't know if it will do it all the way to red line cause I usually shift between 2-3k. As far as a micro struggle, it's bad enough if you had a cup of coffee it would get spilled all over the place. It is definately related to the car being cold, as soon as the temp guage starts to climb, it's gone. I assume it's in the motor, but I have not ruled out the tranny, although it seems more related to engine rpm than wheel speed. I just hate to take the car to the dealer, 3 hr drive, knowing I'll be driving a rental turd for a week, if, they can duplicate the problem.

Feels kind of like my wheels are shaped like eggs, a very eneven acceleration.

Trailer hitching is when you are pulling a trailer, and as you ease off the throttle, the trailer bumps you from behind, and when you put on the gas, it bumps the other way. That much isn't abnormal for a car with MT, and on the subaru, the driveline is so tight that you really feel it. That itself can spill some coffee. But --

But I won't doubt that you might have something altogether different. How long have you had your car and how long has this been going on? Maybe there is something going wrong in the cold-start program. Might be discovered with some logging.

Why dont you let your car idle for a few minutes until the temp. gauge starts to register, then drive down the gravel road in second gear at 2k rpm and tell us how it feels.

Are you describing clutch shudder?

Do STi's get clutch shudder? I thought that was due to the 5spd and the flywheel.

Mine used to do this in the fall. Then I threw some dry gas treatment in and it went away.

qphilo: had the car around two months, used with 25000 on the clock. After your description, definately not "trailer hitching", this is not a hard bump or thud, it just feels like all the tires are shaped like eggs except the pulsations change with rpms. It isn't slack in the drive line. Imagine one person standing in front of you, one behind and both forcefully pushing you back and forth, not slapping, slamming or bumping, but putting their weight into it. No strange noises, no cels.
It just started doing this as the weather has turned cold, around 30 or so.
theicewall: if the car idles long enough for the temp guage to get say 1/8 of the way to the first mark, it won't do it. I live about 100 yards down a gravel road and let the car idle down the road till I get to the hwy., by them the temp guage has moved a bit and it goes fine. This may be why the problem hasn't shown earlier. I leave for work in the morning letting the car warm up while idling down the gravel, when I leave work in the afternoon, no gravel roads just turn the key let it warm for a bit and go, but the weather was very warm for this time of year, just these past few weeks the temps have dropped enough during the day for the problem to show. (idle down the gravel in the newer vehicles, just hate to see all those rock pecks on my paint.)
Stanley: No, I don't think it's clutch shudder. This is in 1,2,3 gears, no clutch, no hard acceleration, pulses seem to change with rpms, by third gear I'm sitting at the stop light waiting my turn, when I take off from the stop things are fine. The speed limit there is 35 and I don't run much over that if at all, cause as we all know, an STI is a cop magnet!!!
Corkfish: I will try some gas treatment. I have never had bad gas from this station before, but ya never know. Station down the road sells e85, could run a couple gallons through, that should pull any water out and clean things up.

On a side note, I was thinking of doing a silencer delete but when I looked the previous owner had replaced it with the GP moto elbow. I have wondered what else he might have done. How would I tell if he had the ecu programmed? If I took the car in under warranty and they came back saying it had programming and other mods and wouldn't cover it what would I do? The dealer I bought if from said many times if I had any problems at all it was under warranty.


picking your brains guys.....

My car does that in first gear if I dont touch the gas while warming up and im coasting at low rpms in a parking lot. It basically felt like it was going to stall. The fix, I updated my Cobb map and it went away. What do I think it was? A combination of low rpms, the ecu idling the car higher than the speed it is travelling at causing the car to slow down, think its stalling, elevate rpms, slow down, think its stalling, elevate rpms, repeat. I think the best way to avoid this is like I said before. Let the car idle before you drive it for a few minutes, then drive it for a few hundred yards in 1st gear at 2,200rpms and you should be fine.

Oh God, my first week with my 2004 WRX, and you guys speak this weird Subarian dialect! I guess I've got this new language... "silencer delete", "Cobb maps" good-grief in the hell are those ;O). I get the same feeling with my car. I notice it more if I'm accelerating. Example, in third at 2k RPM, I press about 90% full throttle and while it is accelerating, it feels as if it hits week spots. If I would guess, I would think perhaps a sparkplug misfire. Slight shudder. According to car-fax, I'm the third owner, and I'm stressed someone beat the hell out of it or applied mods (x-box term) to boost hp. I'm gonna be glued to these forums, and bug the hell out of my new dealer.

I have the same problem every morning when i leave for school. I think that this problem just runs in the subaru family. but i found out that if you let your car run for about 5 minutes it wont do it nearly as bad or not even at all.. Give it a try.

Brody

I also got my WRX used, and have also suspected at times that the ECU might have been remapped. There are a few non-stock behaviors, and it really makes diagnosing other things a challenge.

Maybe a Scooby Specialist could come in and run down the cold start program for us. The timing of your problem suggests the causes may be in there if the problem goes away when the engine reaches operating temperature. A bad sensor or sticky injector or air valve might cause the motor to hunt around. These things all interact in peculiar ways, and especially during cold start. No CEL I guess.

I usually shift between 2-3k.


Wow that is a very low rpm to be trying to accelerate a cold car. On the 2.0 L WRX your lugging the engine if your accelerationg at that low an rpm. Although the 2.5 has more torque, when the engine is cold it will act a lot like the 2.0 engine. Get some rpm and keep it in a lower gear for a bit longer. A cold engine needs to be run near its torque peak rpm to avoid lugging the engine, light load, a bit more rpm than usual, in a gear one lower than you would with a warm engine is actually easier on the engine than asking it to pull hard a very low rpms.

I seldom let my engine drop below 2500 rpm at any time, usually cruise on a warm engine near 3000 rpm to a minimum of 2600-2700, below that you can feel that your pulling the engine out of its torque band and it is working awfully hard to gain rpm.

In cold weather, ( 20's -30's) I start the car, let it idle for about 30 seconds and then pull out of the parking spot, hold it in low gear until I get up to almost 3000 rpm or slightly over before I shift into second. Once in second, I take it up to about 3500 before I shift to 3rd.


Try a bit more rpm, and a lower gear, and you'll probably have a much happier engine.

Larry

I have the same problem every morning when i leave for school. I think that this problem just runs in the subaru family. but i found out that if you let your car run for about 5 minutes it wont do it nearly as bad or not even at all.. Give it a try.

Brody

Is this normal for the STI or wrx in general? If it takes 3+ minutes for it to warm up enough to drive, that sux. What about when it gets like 15-20 degrees out? It might take 5+minutes to warm, I could take the truck and be to Wally world and back before the car was ready to drive.

surely this isn't normal???

Yeah you could, lol! You can always get a remote starter and leave the car in neutral with the ebrake on. The surging and lack of power mixed together very well might be the car lugging and feeling like its going to stall while accelerating at that low of an rpm. I was able to decrease that by 2/3 by installing an APS cast Y-pipe and even more so with accessport, but just the pipe alone should help a bit with that.

Wow that is a very low rpm to be trying to accelerate a cold car. On the 2.0 L WRX your lugging the engine if your accelerationg at that low an rpm. Although the 2.5 has more torque, when the engine is cold it will act a lot like the 2.0 engine. Get some rpm and keep it in a lower gear for a bit longer. A cold engine needs to be run near its torque peak rpm to avoid lugging the engine, light load, a bit more rpm than usual, in a gear one lower than you would with a warm engine is actually easier on the engine than asking it to pull hard a very low rpms.

I seldom let my engine drop below 2500 rpm at any time, usually cruise on a warm engine near 3000 rpm to a minimum of 2600-2700, below that you can feel that your pulling the engine out of its torque band and it is working awfully hard to gain rpm.

In cold weather, ( 20's -30's) I start the car, let it idle for about 30 seconds and then pull out of the parking spot, hold it in low gear until I get up to almost 3000 rpm or slightly over before I shift into second. Once in second, I take it up to about 3500 before I shift to 3rd.


Try a bit more rpm, and a lower gear, and you'll probably have a much happier engine.

Larry

I am accelerating slowly, not much pull at all, really. A Chrysler mini van with two spark plugs fouled would blow my doors off. If I let it rev further than say 3k and shift at a higher rpm, it is still there. No difference other than the pulses get quicker with the rpms.
I can definately tell the motor is happier if kept spinning above 2500 in town, even on flat roads.

Do STi's get clutch shudder? I thought that was due to the 5spd and the flywheel.

My STi seems to suffer from this problem.

I have the same problem in an 03 wagon. I have an Access Port but I want to say that the problem was there before the Access Port went in. The access port just means i have more power when the problem occurs, makes it more pronounced. I have the latest maps so remap isnt necessarily the answer.

I have a 03 WRX Wagon and I had this problem under my Warranty last year. I would notice that the car was having a hard time cranking when it was in the 20’s (degrees). I took the car to the dealer and they told me that the battery had a bad cell and they replaced it. They also told me that the acceleration problem that we are having was because of the voltage on the battery dropping too much. I thought this was total BS, but after they replaced the battery, dam if it was fixed. The rest of the winter it was fine and I didn’t think of this again.
Well here I am a year later, and the WRX is having a hard time starting in the cold and the stuttering is back. It feels like a clutch shudder or lack of power under acceleration, just like before. I don't have a dead cell this time, but I noticed that when I do fell the stuttering under acceleration, my voltage is low. (I have a volt meter now in the car). I am thinking that I need to replace my alternator and/or battery again. No CELs come on and there are no battery warnings either. The car doesn't think there is something wrong with the battery/alternator, but I can watch the voltage drop to 12.4v and at that time I am having some serious stuttering in the acceleration.
I am going to check my belts and possible replace the alternator and because of this under charging, I am wondering if this bad charging has killed my second battery...?