Skip to content
View in the app

A better way to browse. Learn more.

Ultimate Subaru Message Board

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

Dealership can't even figure out engine? problem with my Legacy Wagon

Featured Replies

Just needed some advice i might be able to give to the service dept. I bought an 05 Ltd. Legacy Wagon 2.5i in February from the Subaru dealership in Annapolis. Had about 10,000 miles on her. no problems for a while but after about 4-5K miles, each time I fill the tank up the whole way, for the first 1-5 miles from the gas station the car will hesitate, sometimes severely, chck engine light comes on, etc. A mile later and for the next 420 before filling up again, no problem at all. I took her in, they checked things out and couldn't find anything, kept happening so I took her in again where they filled it up to replicate the problem and replaced 2 fuel injectors cuz they were spraying wrong? anyway, after getting her back it happened again the next time I filled her up, but i didn't even stop and but another 150 miles on her before i did, again with no problems after a minute of it happening 2-3 times.

 

By hesitating, i mean i'll hit the gas and start to speed up, then it will be like the car has no power for half a second, or as if i had a standard and didn't take the clutch out right.

 

So now they want me to take it back in, i don't know what the hell is wrong with it, but I have filled her from the gas light being on and putting 15 gallons in, ALMOST filling her up but being careful not to add the last half gallon or so, and I have experienced no problems. ANy thoughts, ideas?

 

So now they want me to take it back in, i don't know what the hell is wrong with it, but I have filled her from the gas light being on and putting 15 gallons in, ALMOST filling her up but being careful not to add the last half gallon or so, and I have experienced no problems. ANy thoughts, ideas?

i dont think that its a gas problem at all.

 

that sounds EXACTLY like what my legacy was doing when the MAF sensor went bad.

 

(i don't know how car savvy you are, so:

MAF sensor - A sensor that is attached to the air intake that measures the amount of air the engine is sucking in. this, in turn, tells the engine how much fuel to used based on the air/fuel mixture.

air intake - open your hood, it's that long black plastic thing that comes out the back of the engine.)

 

sorry, i hope i'm not insulting your intelligence or anything. i just dont want you to be confused.

I would suspect something related to the fuel pump. Not necessarily the fuel pump its self, but a component controlling the fuel pump. There is a pressure sensor in the fuel tank, your car "knows" when the gas cap has been removed. That's why you'll get a CEL if you don't tighten the gas cap all the way. It only happens when you refuel, my money is on that sensor or related components. Another possibility could be that the loss of tank pressure is causing an intermittent failure in your fuel pump, the check valve, maybe.

 

Anyway, what error code did the dealer pull? That too, would be an excellent place to start.

Yeah That Sounds Like A Sensor.. In My Toyota Mr2 My Mass Air Flow Sensor Messed Up. And I Was Bogging Out At About 3 To 5 Hrand Rpm My Car Was Like Garbage Then After That It Was All Good..

<<i dont think that its a gas problem at all.

 

that sounds EXACTLY like what my legacy was doing when the MAF sensor went bad.

 

(i don't know how car savvy you are, so:

MAF sensor - A sensor that is attached to the air intake that measures the amount of air the engine is sucking in. this, in turn, tells the engine how much fuel to used based on the air/fuel mixture.

air intake - open your hood, it's that long black plastic thing that comes out the back of the engine.)

 

sorry, i hope i'm not insulting your intelligence or anything. i just dont want you to be confused.>>

 

 

the 05's don't have a MAF sensor.

Im putting my money on the evaporative system. Thge system is made to handle gas fumes, it is not designed to handle liquid. For some reason it is sucking up fuel. I know how we are all good and go by the mfg directions and never put more gas in beyond the first click on the pump handle, so i wont even suggest you are doing that :grin:

This really is a no brainer for the dealer. If it always happen take the tech with you to the gas station and fill up the car and how him. YOU have to fill it, not him. Also have him bring the code reader so he can see the engine parimeters in real time

 

nipper

^^^^^ding ding ding ding! BEST place to start is nipper's post.

 

The evap system is the ONLY system that is likely to 'care' about a full tank vs an 'almost' full tank.

 

what code was set in the ECU?

 

 

Carl

I concur with Nipper, and the Texan, that was my inital thought after i read your first post, before seeing theirs.

 

Now, since this is a brand new vehicle, and if Subaru is gonna do the right thing, there gonna figure this out for you.

 

 

 

but..... if this was me, i wouldn't top off after the pump shuts off.

  • Author

All good answers , and no you weren't insulting my intelligence.

 

Nipper your answer does seem to make sense...i have been guilty of this mortal sin. the thing is the dealer did fill it up and replicate the problem once...is there a chance he did the same thing?

 

what does "what code was set in the ECU?" mean? are you asking what check engine light code came up? Do you think he would tell me?

 

I'm gonna go fill up the tank at lunch, and see what happens. Thanks!

Its good it happened to him. Its bad that mortal sin that you commit :)

The ecu will store codes. Most codes will trigger the ecu, a few dont. Also some codes dont stay in memory (since they are minor or do not happen long enough to be considered a hard fault). Also when you use a scanner, you can read the sensors in real time to see what they are doing, and it will also tell you (i think) wetaher certin valves are opned or closed. You may have a stuck purge valve. A stuck valve may not throw a code, but if the coil for the valve was dead that would throw a code.

 

nipper

All good answers , and no you weren't insulting my intelligence.

 

Nipper your answer does seem to make sense...i have been guilty of this mortal sin. the thing is the dealer did fill it up and replicate the problem once...is there a chance he did the same thing?

 

what does "what code was set in the ECU?" mean? are you asking what check engine light code came up? Do you think he would tell me?

 

I'm gonna go fill up the tank at lunch, and see what happens. Thanks!

 

when the check engine light comes on it sends information to the car's computer and the computer saves the problem in the form of a code. when you take it to the garage, they hook up a code checker to your car's computer that reads any and all saved errors. this may only come up as a number, or it may be a number and a breif explanation.

 

something you could do it go to pepboys and have your computer scanned for codes. if they find a code they'll let you know what the number is (and may actually tell you what the problem is. i've never done gone to pepboys to do this personally, but people here will tell you it's possible.)

 

then you could bring the code back here are get some more educated opinions as to what the code means and what you should start doing about the problem.

 

it's very odd though that the dealership got a code and doesn't know what to do....

It might be worth reminding, please make certain the gas cap is refitted very securely. Make it 'click' a dozen times. If it is spun on in a cavalier manner it may not seal and that will trigger an evap system code and CEL.

 

Carl

It might be worth reminding, please make certain the gas cap is refitted very securely. Make it 'click' a dozen times. If it is spun on in a cavalier manner it may not seal and that will trigger an evap system code and CEL.

 

Carl

 

yeah, but i've never heard of a car running weird with an improperly sealed gas cap

Scan for codes when the problem is happening, like they said earlier, go to the dealership and pick up your friendly Subaru technician and drive him/her down the street to the gas station. Fill the tank and replicate the problem, and have him read the codes while it's happening.

 

Then you'll have a better indication of what's going on.

 

matt

Please sign in to comment

You will be able to leave a comment after signing in

Sign In Now

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.