2001 Subaru H6 intermittant engine missing on the freeway

[skikir]

I have a 2001 LL Bean H6 with about 120K miles. I have had a fe
incidents of the engine sputtering, missing, cutting out like th
ignition is quitting. All were on the highway after many hours driving
The first time after a while I crammed the throttle to the floor whil
going up a hill and it went a way. I hoped it was just some bad fuel.
I happened again on a couple of other trips but the full throttle tric
didn't make it go away. It just seemed to come and go. Always on
long trip. Unnerving when a couple of hundred miles from home. Neve
seems to do it around town. No CELs and I ran a diagnostic with my cod
reader and nothing stored. Anyone have an idea like maybe an ignitio
amplifier over heating

 

[Carl 1 Lucky Texan]

I have a 2001 LL Bean H6 with about 120K miles. I have had a few
incidents of the engine sputtering, missing, cutting out like the
ignition is quitting. All were on the highway after many hours driving.
The first time after a while I crammed the throttle to the floor while
going up a hill and it went a way. I hoped it was just some bad fuel.
I happened again on a couple of other trips but the full throttle trick
didn't make it go away. It just seemed to come and go. Always on a
long trip. Unnerving when a couple of hundred miles from home. Never
seems to do it around town. No CELs and I ran a diagnostic with my code
reader and nothing stored. Anyone have an idea like maybe an ignition
amplifier over heating?

hmmmm....I'd expect you would at least have a 'generic' misfire code
stored. weird. Maybe an inspection of the plugs would help pin things
down to a specific cylinder or something?

I dunno - if it would ever do that while idling or throw a code, much
easier to track down.

Carl

 

[Tony Hwang]

I have a 2001 LL Bean H6 with about 120K miles. I have had a few
incidents of the engine sputtering, missing, cutting out like the
ignition is quitting. All were on the highway after many hours driving.
The first time after a while I crammed the throttle to the floor while
going up a hill and it went a way. I hoped it was just some bad fuel.
I happened again on a couple of other trips but the full throttle trick
didn't make it go away. It just seemed to come and go. Always on a
long trip. Unnerving when a couple of hundred miles from home. Never
seems to do it around town. No CELs and I ran a diagnostic with my code
reader and nothing stored. Anyone have an idea like maybe an ignition
amplifier over heating?

Hi,
In the dark, open the hood and see if you can see sparks fly around
along each plug wire. Next I'd inspect plugs. I install Iridium plugs.
They last long time.

 

[johninky]

"only after many hours of driving" suggests everything under the hood
becomes heatsoaked. I would suspect the coil pack.

 

[Augie Pabst]

I have a 2001 LL Bean H6 with about 120K miles. I have had a few
incidents of the engine sputtering, missing, cutting out like the
ignition is quitting. All were on the highway after many hours driving.
The first time after a while I crammed the throttle to the floor while
going up a hill and it went a way. I hoped it was just some bad fuel.
I happened again on a couple of other trips but the full throttle trick
didn't make it go away. It just seemed to come and go. Always on a
long trip. Unnerving when a couple of hundred miles from home. Never
seems to do it around town. No CELs and I ran a diagnostic with my code
reader and nothing stored. Anyone have an idea like maybe an ignition
amplifier over heating?

Hi - I've had exactly the same problem - usually after a long run on a
motorway (UK) - it's as if the engine just 'dies' but after a momement of
panic (in the fast lane at 70mph) and slowing down it just seems to right
itself as if nothing has happened! And then everythings fine for another
1000 miles! Weird - and NOT good. Never happened with my 1999 2.5 Legacy
......