hawkeye27dr Posted July 11, 2011 Share Posted July 11, 2011 Hi Have been driving my legacy gt for a couple weeks now (Automatic) Still very new to the subaru and turbo engine scene so please bare with me. Been reading that people have come across significant lag in acceleration. I wanted to know if my case is the norm or maybe its extreme and something's wrong. Mind you I've taken the car to multiple mechanics, have had computers run through it to tell me the car is in fine condition. At certain points especially on the highway, I'm driving at lets say 20-40 mph once in a while the hit the gas and the car won't accelerate. Instead I hear the turbo revving but it doesn't end up kicking in. I might be there for a good 5 secs and then after removing my foot off the gas and reapplying it the car picks up slowly. Is this something that's been heard of? Would changing the up pipe improve the response of the car in terms of acceleration? Mind you this doesn't happen every time but out of every 150 miles I drive...it's likely to happen a couple of times. Thanks. Link to comment Share on other sites More sharing options...
bmx045 Posted July 11, 2011 Share Posted July 11, 2011 Possibly a slipping transmission, is what it sounds like. The fact that you hear the engine increasing RPM and the acceleration not happening means the power is not getting to the wheels. How does the car idle? I suppose a boost leak could cause poor acceleration, from a loose hose etc.. Link to comment Share on other sites More sharing options...
hawkeye27dr Posted July 11, 2011 Author Share Posted July 11, 2011 that's what I thought as well about the loose hose but according to my mechanic that's not the case. The car is fine idle no issues. Only note this problem while driving on the highway in the 20-40 mph range when I'm trying to accelerate higher. Link to comment Share on other sites More sharing options...
frank_ster Posted July 11, 2011 Share Posted July 11, 2011 are you putting the pedal to the floor ? Now that's thinking out of the boxer! fyi all 05 + legacy's have built in code reader Link to comment Share on other sites More sharing options...
lieutenantcolumbo Posted July 11, 2011 Share Posted July 11, 2011 OP try using the manumatic feature of your transmission. Test out the acceleration in 3rd gear. If you have no problems with that gear after a number of tries, then repeat the acceleration tests in 4th gear. If no problems there, then try 5th gear, which is probably the one that is slipping the clutches. This may or may not show you which gear is failing, because when you use the manual mode, a higher line pressure is applied which can help mask the symptoms of a failing clutch. Also for future reference it's never a great idea to go WOT in a stock 5eat while in 5th gear. You should downshift or get your valve body upgraded. If you're slipping in 5th I would advise you to drive exclusively around in manumatic mode and don't use 5th gear at all. I did that for a couple of months. That will give you time to find a good transmission shop and start saving some money. If you end up getting your transmission rebuilt you should also consider adding a transmission cooler and doing a valve body upgrade such as this one: http://legacygt.com/forums/showthread.php/5eat-valve-body-upgrades-finally-164484.html Link to comment Share on other sites More sharing options...
hawkeye27dr Posted July 11, 2011 Author Share Posted July 11, 2011 Not slamming the pedal to the floor. Just accelerating normally as I would in any other car. It might be somewhat aggressive but not to the floor. I"ll try messing with the manual feature. If the tranny is the issue i have no freaking clue why it wasn't picked up at the mechanic or by the comp sensors at a couple different places. Link to comment Share on other sites More sharing options...
frank_ster Posted July 11, 2011 Share Posted July 11, 2011 i don't think there is a problem, the computer in the car is trying to save gas, when your accelerating like you say the engine is loaded down at a low rpm and its prevented to shift unless your push further on the throttle. so make sure your tranny and everything is working fine. just come to a complete stop and floor it untill 60-70- or what ever mph your comfortable with. does the car keep going ? or does it sit on the revlimiter at some point ? Now that's thinking out of the boxer! fyi all 05 + legacy's have built in code reader Link to comment Share on other sites More sharing options...
Max Capacity Posted July 11, 2011 Share Posted July 11, 2011 When you say 20-40mph on the highway makes me ask why your going that slow on the highway. Most highways have a minimum speed limit of 40mph. Most fokes travel at the posted speed limit 65mph or a little more. I'm not a big automatic guy but IMO the trans should downshift to a lower gear when you increase the throttle angle, when it does that, the engine rpms should jump up to the power band of the engine. What does the Tach do when you stuff your foot into the gas pedel when the cars in drive at 40mph? 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
lieutenantcolumbo Posted July 11, 2011 Share Posted July 11, 2011 just come to a complete stop and floor it untill 60-70- or what ever mph your comfortable with. does the car keep going ? or does it sit on the revlimiter at some point ? A lot of the transmissions fail from the top gear down, i.e. 5th, then 4th. OP will never even get to 5th using the method above since 3rd gear will get you close to 100mph. If the tach is climbing and the car isn't accelerating during any of the pulls using the manual mode, then he will know the clutches are failing. Link to comment Share on other sites More sharing options...
hawkeye27dr Posted July 18, 2011 Author Share Posted July 18, 2011 wanted to post a little update to my aforementioned issue Spoke to my dad and brother about it and they both thought it sounded like a MAF sensor issue. So my dad took it out and cleaned it, it was super dirty, popped it back in and drove the car. Took the car out for a short spin and drove as aggressively as I could. Car was 10x more responsive. No lag on acceleration, only the expected 5EAT slight turbo lag. Drove it as hard as I could in terms as putting the throttle to the test and the car seemed to drive as it should. I don't want to seem too optimistic yet since the car underperformed even more so when I would drive for long periods of time. I'll see the real test when I drive back to work on Tuesday. IF that's the case, I'll prob replace the MAF sensor with a new one. and if it all works out.... then i can use my 'rebuild tranny' fund to mod the car. Link to comment Share on other sites More sharing options...
Rexwagon Posted July 19, 2011 Share Posted July 19, 2011 Have you tried reseting the ecu? See if it becomes a little more peppy? Link to comment Share on other sites More sharing options...
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