kbohip Posted January 19, 2013 Share Posted January 19, 2013 My wife's '05 with 45k miles has started idling high on cold starts. It shoots to about 1,800 rpm when it first starts then usually hovers around 1,500 rpm. If I blip the throttle it then settles down to what I consider a normal cold idle of around 1,100-1300 rpm. At first I was thinking something might be wrong but then I had the chance to drive my mom's '11 Outback with 13k miles on it the other day. Sure enough, on a cold start it shot up to 2,000 rpm and then hovered around 1,800 rpm! I blipped the throttle and it dropped to 1,200 rpm just like my wife's. Is this just normal behavior for Subaru's 2.5 engines? Link to comment Share on other sites More sharing options...
iNVAR Posted January 19, 2013 Share Posted January 19, 2013 normal. Link to comment Share on other sites More sharing options...
-Samurai- Posted January 19, 2013 Share Posted January 19, 2013 Completely normal. It will ease down as it gets warmer. Nothing to worry about. Link to comment Share on other sites More sharing options...
apexi Posted January 19, 2013 Share Posted January 19, 2013 It has to do with the PZEV system. The car is trying to heat up the catalytic converter quicker, since they aren't very efficient when cold. From Cars101 http://www.cars101.com/subaru_terms.html "PZEV partial low emission vehicle a brief, simple summary (2008) The EPA says a PZEV is the cleanest running gas car on today's market based on emissions testing for carbon-containing compounds, oxides of nitrogen, particulate matter, and other tailpipe nastiness. For 2008 it is required in CA, CT, NJ, NY, MA, ME, RI, VT, PA, OR, and WA. in 2011 it is required in CA, CT, MA, MD, ME, NJ, NM, NY, OR, PA, RI, VT, WA How it works, a brief, simple summary. 1. A charcoal cannister catches unburned gas left in the engine when it's turned off so it doesn't just evaporate. 2. Fuel injectors that close tighter when they're not in use. 3. A finer mesh in the catalytic converter, as well as optimized placement of its precious metal. 4. The engine's electronic brain is tuned to run the hot at start up to help the catalytic converter heat up so it can start doing its job faster" Link to comment Share on other sites More sharing options...
iNVAR Posted January 19, 2013 Share Posted January 19, 2013 His car isn't designated a PZEV vehicle. Link to comment Share on other sites More sharing options...
apexi Posted January 19, 2013 Share Posted January 19, 2013 You're right, my mistake. Didn't realize his wife's '05 was a turbo. Link to comment Share on other sites More sharing options...
scoobie_Bspec Posted January 19, 2013 Share Posted January 19, 2013 Wow i was just about to ask something similar, the difference is my 08 on a cold start its up to 15k. I hate to ask on your thread but, is it normal that the car may feel slower and making that is not as quick from first purchase? Link to comment Share on other sites More sharing options...
iNVAR Posted January 19, 2013 Share Posted January 19, 2013 What, what do you mean, the car feels kind of sluggish/slow when it's cold out and you first start it? That's because it's not warmed up yet. Stay below 3K and do not go full throttle until it's warmed up! And my warmed up, I don't mean start it up in your driveway and wait... that only warms up the engine. There are a lot of other things in your car that need to get warmed up that can only do that when you're driving. I start my car, wait 20 seconds, and then start driving very gently immediately. Link to comment Share on other sites More sharing options...
kred Posted January 19, 2013 Share Posted January 19, 2013 I've noticed the same thing in my car, so it's perfectly normal. How's the idle on your wife's car when rolling with no throttle (rolling in no gear if manual)? I have a 5MT, and I noticed that when rolling in neutral in cold weather, my car will idle up to 1500 rpms, then drop to like 750 when I stop, provided that the car is warmed up by then. Link to comment Share on other sites More sharing options...
famaya26 Posted January 19, 2013 Share Posted January 19, 2013 My car always idles around 500-800. Is something wrong? Link to comment Share on other sites More sharing options...
iNVAR Posted January 19, 2013 Share Posted January 19, 2013 You live in Texas where the temperatures don't get that cold. You shouldn't be as low as 500 though. Here's what a stock idle table looks like: I believe the top table is a "high load" table when AC/blower and other things are on. Bottom table is a "normal load" table. Link to comment Share on other sites More sharing options...
LewisI Posted January 20, 2013 Share Posted January 20, 2013 My Legacy idles as low as 400rpm when warm according to the tachometer, but using OT2 OBD II it's more like 650rpm When cold (50 degF) it reaches 2000rpm , but what I started doing was to disconnect the battery erase ecu memory and then in the mornings just as cold or even colder it only reaches 1500rpm. It will last for a few weeks and then it revs high again, and I disconnect the battery again. I just don't like the idea of it revving high when cold. Link to comment Share on other sites More sharing options...
rob-2 Posted January 20, 2013 Share Posted January 20, 2013 It's high idle protects the motor, don't blip the throttle and just drive it gently. Pretty sure Subi says no more than 50% throttle until fully warmed up. Keep in mind the car was designed to idle for 30-45 seconds before being driven. Warm up idles are a thing of the past. Link to comment Share on other sites More sharing options...
kbohip Posted January 20, 2013 Author Share Posted January 20, 2013 Sorry guys, I should have mentioned that this high idle occurs in Park after the car has just been started. The idle is higher when the car has sat for at least 6 hours or so, even in a garage that doesn't go below 40 degrees. When the car is in gear the idle is right where it should be. I'm just a bit concerned that after a few hundred cold starts and my wife dropping it into reverse when the engine is at 1,500+ rpm's, it might cause some transmission issues or even problems with the mounts. The car runs perfect, with tons of power and the gas mileage has been excellent too. The record for my wife in the city was 23mpg. She averages 20mpg city most of the time though. With that said, I don't think there's anything off with say an oxygen sensor. Thanks for posting that chart Lewis. Those numbers seem to be close enough to what her car idles at on a start at the temps on the chart. I'm probably just over thinking this issue, but I'd rather ask here first than have a problem come up down the road that could've been prevented now. Link to comment Share on other sites More sharing options...
iNVAR Posted January 20, 2013 Share Posted January 20, 2013 Yep, you're overthinking it. I'd be concerned if the idle never dropped even after warming up... that might indicate a vacuum leak. But if it drops and idles around 850 after it's all warmed up, it's fine. Lewis, you shouldn't be resetting your ECU, not because of the idle. It's supposed to idle higher when cold. Link to comment Share on other sites More sharing options...
2manysubies Posted January 21, 2013 Share Posted January 21, 2013 iNVAR, Your a very PATIENT Man. R/Mac Link to comment Share on other sites More sharing options...
a93x Posted January 21, 2013 Share Posted January 21, 2013 /thread torque impresses girrls, hp impresses flat-bills Link to comment Share on other sites More sharing options...
stuck686 Posted January 21, 2013 Share Posted January 21, 2013 it was -10 today in the morning and when i started my car it idled at almost 2000! lol. i let it sit for 15min before driving Link to comment Share on other sites More sharing options...
iNVAR Posted January 21, 2013 Share Posted January 21, 2013 Completely unnecessary. Link to comment Share on other sites More sharing options...
stuck686 Posted January 21, 2013 Share Posted January 21, 2013 what was?? Link to comment Share on other sites More sharing options...
mattg Posted January 21, 2013 Share Posted January 21, 2013 warming up for 15 min. Link to comment Share on other sites More sharing options...
stuck686 Posted January 21, 2013 Share Posted January 21, 2013 but it gave me time to get dressed etc and i live right by the freeway so i need it warmed up right when i drive Link to comment Share on other sites More sharing options...
iNVAR Posted January 21, 2013 Share Posted January 21, 2013 but it gave me time to get dressed etc and i live right by the freeway so i need it warmed up right when i drive What, what do you mean, the car feels kind of sluggish/slow when it's cold out and you first start it? That's because it's not warmed up yet. Stay below 3K and do not go full throttle until it's warmed up! And my warmed up, I don't mean start it up in your driveway and wait... that only warms up the engine. There are a lot of other things in your car that need to get warmed up that can only do that when you're driving. I start my car, wait 20 seconds, and then start driving very gently immediately. If the problem is you don't want to sit in a freezing cold car, then okay, you can warm it up before you get in so the heat is nice and toasty. BUT REMEMBER, just because your engine is warm doesn't mean other things in your car are warm (transmission, axle, brakes, differentials, suspension, etc. etc. etc.) so don't drive it like it's actually warmed up yet. No flooring don't rev above 3K if possible, etc. That's why I recommend driving it. Idling it is a waste of gas, and arguably not that great for your catalytic converter. Link to comment Share on other sites More sharing options...
rob-2 Posted January 22, 2013 Share Posted January 22, 2013 Sorry guys, I should have mentioned that this high idle occurs in Park after the car has just been started. The idle is higher when the car has sat for at least 6 hours or so, even in a garage that doesn't go below 40 degrees. When the car is in gear the idle is right where it should be. I'm just a bit concerned that after a few hundred cold starts and my wife dropping it into reverse when the engine is at 1,500+ rpm's, it might cause some transmission issues or even problems with the mounts. The car runs perfect, with tons of power and the gas mileage has been excellent too. The record for my wife in the city was 23mpg. She averages 20mpg city most of the time though. With that said, I don't think there's anything off with say an oxygen sensor. Thanks for posting that chart Lewis. Those numbers seem to be close enough to what her car idles at on a start at the temps on the chart. I'm probably just over thinking this issue, but I'd rather ask here first than have a problem come up down the road that could've been prevented now. Worry about other things. The tranny can catch the motor at 1500rpm without problem. 3k no. Move on and find other things to keep you Link to comment Share on other sites More sharing options...
rob-2 Posted January 22, 2013 Share Posted January 22, 2013 If the problem is you don't want to sit in a freezing cold car, then okay, you can warm it up before you get in so the heat is nice and toasty. BUT REMEMBER, just because your engine is warm doesn't mean other things in your car are warm (transmission, axle, brakes, differentials, suspension, etc. etc. etc.) so don't drive it like it's actually warmed up yet. No flooring don't rev above 3K if possible, etc. That's why I recommend driving it. Idling it is a waste of gas, and arguably not that great for your catalytic converter. Driving the car gets higher oil pressure which protects the motor. Idling a cold motor isn't very 'good' though generally speaking you're never going to be able to measure the downside. Start, idle for 30-45 sec and drive nicely. The car warms best up driven. Under 4K and less than 50% throttle. In the track car, until it's really warmed up it lowers the redline. I wish more cars were that smart. Subi's should cut boost and a/f until ready for power. Link to comment Share on other sites More sharing options...
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