[Sequoia225]

As some have read from me, my 2003 OB at 240K is on its way out, but I was just curious to ask these questions here.
2 issues its had for years now that no one can seem to fix (3 diff mechanics that work on Subarus a LOT).

A.
One problem is that on cold mornings (I live in So Cal BTW so I mean about 40s and 50s), about the first 15 minutes, my gas pedal seems to "stick".
More clearly, I have a manual, and when I shift, the gas keeps feeding even though I release the pedal to shift, and if anything, it seems to rev a bit more, maybe because Im pushing in the clutch.
If I DONT shift - and just release the gas pedal, it seems to keep feeding gas for a bit then stops.
I had the same problem while driving a LONG trip through freezing temps - so, point being, car was hot from driving already, but SOMETHING was still cold from the ambient temp enough that when I got off freeway to get gas - it was doing the same problem. Im guessing in average cool temps, the engine compartment heats enough to heat the problem spot and the problem stops after some driving, but when Im driving on the highway in freezing temps (which I cant do locally where my mechanic is), its cold enough that the engine DOESNT heat up the problem spot perhaps (whatever that is) so it persists.

Does that make sense?
Its been hard to show any mechanic cause its rarely cold enough here for the problem to last long enough to show them after driving there.


B.
The second issue, is that when I FILL up with gas tank from EITHER low tank or halfway full, for the first 10 or 15 minutes of driving, the car hesitates a bit when giving it gas - just in very short bursts.
This problem has gotten MORE severe in the last year but has existed for a LONG time. About 1.5 years ago - my fuel pump totally went - and was replaced along with the tank cleaned (I believe the mechanic said the pump was in the tank). So my guess is that its not "dirt in the tank" like some people say. This ONLY happens when I fill the tank up but happens even if the tank is ALREADY more than half full - as the other night it happened and I was just topping off because I happened to be at costco already. Again - its only for the first 10 or 15 minutes of driving after a fill up - then its fine.


So two issues that have existed for years without mechanics being able to solve them. Any ideas are welcome and appreciated.

 

[subiesailor]

As some have read from me, my 2003 OB at 240K is on its way out, but I was just curious to ask these questions here.
2 issues its had for years now that no one can seem to fix (3 diff mechanics that work on Subarus a LOT).

A.
One problem is that on cold mornings (I live in So Cal BTW so I mean about 40s and 50s), about the first 15 minutes, my gas pedal seems to "stick".
More clearly, I have a manual, and when I shift, the gas keeps feeding even though I release the pedal to shift, and if anything, it seems to rev a bit more, maybe because Im pushing in the clutch.
If I DONT shift - and just release the gas pedal, it seems to keep feeding gas for a bit then stops.
I had the same problem while driving a LONG trip through freezing temps - so, point being, car was hot from driving already, but SOMETHING was still cold from the ambient temp enough that when I got off freeway to get gas - it was doing the same problem. Im guessing in average cool temps, the engine compartment heats enough to heat the problem spot and the problem stops after some driving, but when Im driving on the highway in freezing temps (which I cant do locally where my mechanic is), its cold enough that the engine DOESNT heat up the problem spot perhaps (whatever that is) so it persists.

Does that make sense?
Its been hard to show any mechanic cause its rarely cold enough here for the problem to last long enough to show them after driving there.


B.
The second issue, is that when I FILL up with gas tank from EITHER low tank or halfway full, for the first 10 or 15 minutes of driving, the car hesitates a bit when giving it gas - just in very short bursts.
This problem has gotten MORE severe in the last year but has existed for a LONG time. About 1.5 years ago - my fuel pump totally went - and was replaced along with the tank cleaned (I believe the mechanic said the pump was in the tank). So my guess is that its not "dirt in the tank" like some people say. This ONLY happens when I fill the tank up but happens even if the tank is ALREADY more than half full - as the other night it happened and I was just topping off because I happened to be at costco already. Again - its only for the first 10 or 15 minutes of driving after a fill up - then its fine.


So two issues that have existed for years without mechanics being able to solve them. Any ideas are welcome and appreciated.

I'm in Norcal - 40-50 degree temps in the morning the car will spike the idle to warm up the emissions system 1800-2000 rpm though once your down the road a few minutes after the morning start up - it should be fine. If its doing the high idle after say 10-15 minutes on the road then you have some sort of idle issue and it could be tied to the fuel issue you listed. Lots of sensors on these cars - if any of those are wonky or you have a vac hose leak some place this can cause odd issues like this also.

For electronic and very car specific things like this I always have the dealer look it over given the local shops are generalists and will simply take their best guess and start replacing parts. The dealer knows the car has the diagnostics tools to spot the cause and correct it. I've never come out ahead of dealer pricing when it comes to very specific stuff to the car brand when taking it to the local shop. Brakes and the general crap which are nearly identical with all cars the local leo is cheaper than the dealer.

 

[Sequoia225]

I'm in Norcal - 40-50 degree temps in the morning the car will spike the idle to warm up the emissions system 1800-2000 rpm though once your down the road a few minutes after the morning start up - it should be fine. If its doing the high idle after say 10-15 minutes on the road then you have some sort of idle issue and it could be tied to the fuel issue you listed. Lots of sensors on these cars - if any of those are wonky or you have a vac hose leak some place this can cause odd issues like this also.

For electronic and very car specific things like this I always have the dealer look it over given the local shops are generalists and will simply take their best guess and start replacing parts. The dealer knows the car has the diagnostics tools to spot the cause and correct it. I've never come out ahead of dealer pricing when it comes to very specific stuff to the car brand when taking it to the local shop. Brakes and the general crap which are nearly identical with all cars the local leo is cheaper than the dealer.

nah, this isnt an idle issue - and it affects my driving. Its only when Im giving it gas - then let off the gas pedal, the gas keeps feeding for another second or so before it goes back down. Its pretty drastic actually, and I have to adjust my driving accordingly, meaning, I have to let off the gas, wait a second, THEN shift.

My main mechanic here is an ex Subaru dealer mechanic that has his own Subaru independent shop. I think hes great - but its not easy to diagnose problems that you cant see so much. He would have to hold my car overnight, and hope for a cold morning, and drive it first thing in the morning - to even see the problem.

Thank you for your input!

 

[1 Lucky Texan]

on B

do you ever detect a whoosh of pressure or vacuum when you remove the gas cap?

have you scanned for pending codes?

 

[Sequoia225]

on B

do you ever detect a whoosh of pressure or vacuum when you remove the gas cap?

have you scanned for pending codes?

nope, never actually.

I have had endless engine light issues and some other little issues that have been looked at and not very solved, but I dont know if they are connected.

 

[DavidPeab]

Might not be related, but you mentioned topping off. These cars (all modern cars actually) do better if you don't fill up the fuel filler neck. Once the pump pops, round up to the next nickle of you are a stickler about numbers, than stop and put the cap on.

Topping off can effect stuff whose name I can't recall now - some filter or evaporator canister or the like. Someone here will correct me as usual. lol But it may have something to do with your problem, so I took a chance and mentioned it.

 

[Storkiln]

Sequoia, I have the same kind of car - 2003 Outback with manual - live in So Cal with the same weather conditions as you - and you know what, I experience the same thing in the mornings right as I start the car.

For the first few minutes of a cold engine, I feel like the revs "stick" a little longer than usual. Usually the revs drop very quickly (perhaps a boxster engine thing), so I need to give it a little gas while shifting to keep it smooth. Just like you said, when it sticks before warming up, driving smoothly is neigh on impossible.

I've never had it checked out, because it always goes away as the engine warms up. I correlate it to engine temp, thinking that the aluminum block is constricted around the cylinders more on a cold day than a warm day. After the engine heats up, the sticking goes away, so I just live with it.

 

[subiesailor]

Sequoia, I have the same kind of car - 2003 Outback with manual - live in So Cal with the same weather conditions as you - and you know what, I experience the same thing in the mornings right as I start the car.

For the first few minutes of a cold engine, I feel like the revs "stick" a little longer than usual. Usually the revs drop very quickly (perhaps a boxster engine thing), so I need to give it a little gas while shifting to keep it smooth. Just like you said, when it sticks before warming up, driving smoothly is neigh on impossible.

I've never had it checked out, because it always goes away as the engine warms up. I correlate it to engine temp, thinking that the aluminum block is constricted around the cylinders more on a cold day than a warm day. After the engine heats up, the sticking goes away, so I just live with it.

As I said above the high idle on a cold start ie morning start is the normal high idle done to warm up the emissions system. Mine did it all 180,000 miles I had it cold mornings I would start up the engine would rev to 1800- 2000 rpm on its own - I would actually when parked on the street simply drop it in 2nd and go 5 minutes down the road it was warm and idling at 800 or so RPM. No if you actually drive a stick a high idle doesn't impact you much given you simply give it less throttle because its already running at a higher rpm ie power setting to start with. An Automatic on the other hand might be annoying given it wants to launch you through the garage door if its idling fast.

My Gen 4 does the same thing only its the CVT and its far more annoying than the old MT was

 

[subiesailor]

You should hear my 4.7L V8 when it does the cold morning high idle. Not to mention if your not standing on the brake a fair bit your going for a ride when you drop it into gear.

 

[Sequoia225]

Might not be related, but you mentioned topping off. These cars (all modern cars actually) do better if you don't fill up the fuel filler neck. Once the pump pops, round up to the next nickle of you are a stickler about numbers, than stop and put the cap on.

Topping off can effect stuff whose name I can't recall now - some filter or evaporator canister or the like. Someone here will correct me as usual. lol But it may have something to do with your problem, so I took a chance and mentioned it.

Sorry - I shouldnt have used that term "topping off". I actually NEVER top off the tank. I meant only that I just filled up the tank even though there was over half a tank because I was ALREADY at Costco. I just mean that that tank wasnt empty - and I filled it up anyway hoping to delay any need to fill up till next time I go to Costco.

 

[Sequoia225]

As I said above the high idle on a cold start ie morning start is the normal high idle done to warm up the emissions system. Mine did it all 180,000 miles I had it cold mornings I would start up the engine would rev to 1800- 2000 rpm on its own - I would actually when parked on the street simply drop it in 2nd and go 5 minutes down the road it was warm and idling at 800 or so RPM. No if you actually drive a stick a high idle doesn't impact you much given you simply give it less throttle because its already running at a higher rpm ie power setting to start with. An Automatic on the other hand might be annoying given it wants to launch you through the garage door if its idling fast.

My Gen 4 does the same thing only its the CVT and its far more annoying than the old MT was

I had a feeling I wasnt making a lot of sense. haha

I dont mean a high idle, I know what that is when my car does it, and it does do that when its first running, but thats different.

I mean when I am driving from a stop, gaining speed by giving gas, and shifting up to 3rd or 4th, every time I shift, and let go of the gas - the engine revs up obnoxiously, as if the gas mechanism is sticking for a second or two and then it lets off. Its real obnoxious. If I dont shift, but just let off the gas- it does the same - so it doesnt have to do with shifting, its like the gas just sticks when something is cold.

When I was driving 12 hours from New Mexico to So Cal, middle of night - temps were freezing, and I had been driving for 6 hours, and I pulled off to get gas - and so the car had been running a lot for a while - but when I was driving around the town to get the gas - same thing happens - engine revs high after flooring the gas to go - like I still have the gas down for a second or two more every time I let go of it. I mention the temps, cause when the temp is REALLY cold, it doesnt matter if the engine is hot - so I think whatever is failing is something not directly connected to the engine heat, so when its REALLY cold, that "part" still stays cold.

So much easier if I could show someone - haha - and thats my problem. I havent been able to.

 

[subiesailor]

Sorry - I shouldnt have used that term "topping off". I actually NEVER top off the tank. I meant only that I just filled up the tank even though there was over half a tank because I was ALREADY at Costco. I just mean that that tank wasnt empty - and I filled it up anyway hoping to delay any need to fill up till next time I go to Costco.

Side tip - I get considerably better gas mileage with all three of our cars buying the cheap off brand gas at our corner station vs the Costco gas. I ran costco gas in our cars for 6 months all three saw a 3-5mpg drop in their average mileage per tank. The lines and price difference at costco weren't worth it

 

[Sequoia225]

Side tip - I get considerably better gas mileage with all three of our cars buying the cheap off brand gas at our corner station vs the Costco gas. I ran costco gas in our cars for 6 months all three saw a 3-5mpg drop in their average mileage per tank. The lines and price difference at costco weren't worth it

When I get my 13 I will be curious to test this out. I dont care enough about my current OB anymore to worry about this

I am lucky though, I have a newer costco built not far from another one, and the lines at this one are never more than a car or 2 when Im there, I also dont tend to go at peak times either.

But isnt all the gas in Calif fairly similar? I mean, isnt that why there was that huge spike everywhere in CA recently, cause our gas only comes from a couple refineries? Or at least one of our season mixes?

 

[subiesailor]

When I get my 13 I will be curious to test this out. I dont care enough about my current OB anymore to worry about this

I am lucky though, I have a newer costco built not far from another one, and the lines at this one are never more than a car or 2 when Im there, I also dont tend to go at peak times either.

But isnt all the gas in Calif fairly similar? I mean, isnt that why there was that huge spike everywhere in CA recently, cause our gas only comes from a couple refineries? Or at least one of our season mixes?

Hanging idle like you mention could be vac hose leak or can't recall when the direct throttle cable was changed to electronic nanny some place around 2003-2004 I think. If you have a cable it might simply be mucked up and need to be cleaned and oiled. Electronic throttle control then the issue is something a subaru tech with diagnostics equipment would need to look at.

All base gas in CA is identical from one of 4 refineries. Each brand then purchases the base fuel and mixes in their magic potion then trucks it to the station. In many cases you can view the magic potion similar to the bar tender watering down your top shelf drink when your not looking.

 

[Sequoia225]

Hanging idle like you mention could be vac hose leak or can't recall when the direct throttle cable was changed to electronic nanny some place around 2003-2004 I think. If you have a cable it might simply be mucked up and need to be cleaned and oiled. Electronic throttle control then the issue is something a subaru tech with diagnostics equipment would need to look at.

All base gas in CA is identical from one of 4 refineries. Each brand then purchases the base fuel and mixes in their magic potion then trucks it to the station. In many cases you can view the magic potion similar to the bar tender watering down your top shelf drink when your not looking.

as little as I know about cars, I THOUGHT it may be the throttle cable (I didnt know what thats called but I know where it is in the engine). But again, I cant SHOW the mechanic.
I had no idea though that the cable was taken out in the years after my car - thats interesting.

 

[cardoc]

There is a couple things that I see could be an issue and it could be verified with a scan tool in the right hands and an emission smoke machine.

Its not a gas pedal. Its an accelerator pedal or you could call it an air pedal. It controls air input only. Nothing else.

Vacuum leak. It is possible to have a vacuum leak when cold, not have it when running normal temperature or close to it or the opposite. A vacuum leak can cause high idle and the ECM will keep adding fuel at the injector pulse due to the influx of air and the readings it gets from the sensors. A smoke machine attached to a vacuum hose on the intake will show a leak. It can be checked cold, then again at temperature.

Engine temperature, or the false readings from the ECT will effect idle and overall engine performance. If the engine is not reaching temperature, the ECM will continue to run the idle up to try and warm it. If it is getting up to temperature and the ECT is failing or failed, then the ECM, only seeing what is being fed back to it, again will keep trying to warm up the engine.

Sticking IACV.

Dirty throttle body. If the throttle body is dirty, it can be sticking partially open. Look for carbon build up around the bowl of the throttle body and clean it if necessary. I actually see this in a lot of vehicles, not just Subaru, and after cleaning, the idle smooths out. Also, dirty plate shaft or worn bushings.

Leak in the EVAP system. This will also explain the odd engine performance after a fill up. An EVAP leak can create a vacuum leak. A sticking purge valve can also cause a leak.

Also check the Charcoal Canister or Vapor Canister. It may be there is fluid gasoline getting into the canister instead of just the vapor. I had one Subaru that the charcoal filter actually just came apart and collapsed into hundreds of little charcoal pieces that fell out on the floor when I removed a hose. It was original with a lot of miles. Can't remember exactly, but it was over 250K.

It can be found. It could be something that has been overlooked all this time that your technician isn't putting together. It happens. I'm not putting down you tech. It could be one thing causing both issues or different problems altogether. Seems to me both issues are more likely connected, thus leading me to think a leak in the EVAP or vacuum that the computer isn't picking up on.

And one more thing to check, the injector seals. But again, smoking the intake system would show a bad seal.

 

[Storkiln]

As I said above the high idle on a cold start ie morning start is the normal high idle done to warm up the emissions system. Mine did it all 180,000 miles I had it cold mornings I would start up the engine would rev to 1800- 2000 rpm on its own - I would actually when parked on the street simply drop it in 2nd and go 5 minutes down the road it was warm and idling at 800 or so RPM. No if you actually drive a stick a high idle doesn't impact you much given you simply give it less throttle because its already running at a higher rpm ie power setting to start with. An Automatic on the other hand might be annoying given it wants to launch you through the garage door if its idling fast.

My Gen 4 does the same thing only its the CVT and its far more annoying than the old MT was

Ok, I see what you're saying. I'm familiar with the computer setting a high idle on start up, but I just hadn't considered it would keep doing it in the first few minutes of driving. The 7th gen manual Civic I used to have did the high idle on start up (as expected), but it wouldn't keep trying to maintaining the high idle once you set off. I guess Subaru does.

I'll have to copy and save CarDoc's list of diagnoses for future reference. I'm hoping I can get mine past 200k. It's a good little steed.

 

[Sequoia225]

There is a couple things that I see could be an issue and it could be verified with a scan tool in the right hands and an emission smoke machine.

Its not a gas pedal. Its an accelerator pedal or you could call it an air pedal. It controls air input only. Nothing else.

Vacuum leak. It is possible to have a vacuum leak when cold, not have it when running normal temperature or close to it or the opposite. A vacuum leak can cause high idle and the ECM will keep adding fuel at the injector pulse due to the influx of air and the readings it gets from the sensors. A smoke machine attached to a vacuum hose on the intake will show a leak. It can be checked cold, then again at temperature.

Engine temperature, or the false readings from the ECT will effect idle and overall engine performance. If the engine is not reaching temperature, the ECM will continue to run the idle up to try and warm it. If it is getting up to temperature and the ECT is failing or failed, then the ECM, only seeing what is being fed back to it, again will keep trying to warm up the engine.

Sticking IACV.

Dirty throttle body. If the throttle body is dirty, it can be sticking partially open. Look for carbon build up around the bowl of the throttle body and clean it if necessary. I actually see this in a lot of vehicles, not just Subaru, and after cleaning, the idle smooths out. Also, dirty plate shaft or worn bushings.

Leak in the EVAP system. This will also explain the odd engine performance after a fill up. An EVAP leak can create a vacuum leak. A sticking purge valve can also cause a leak.

Also check the Charcoal Canister or Vapor Canister. It may be there is fluid gasoline getting into the canister instead of just the vapor. I had one Subaru that the charcoal filter actually just came apart and collapsed into hundreds of little charcoal pieces that fell out on the floor when I removed a hose. It was original with a lot of miles. Can't remember exactly, but it was over 250K.

It can be found. It could be something that has been overlooked all this time that your technician isn't putting together. It happens. I'm not putting down you tech. It could be one thing causing both issues or different problems altogether. Seems to me both issues are more likely connected, thus leading me to think a leak in the EVAP or vacuum that the computer isn't picking up on.

And one more thing to check, the injector seals. But again, smoking the intake system would show a bad seal.

thanks for your input!