Misfires in 98 Subaru Outback w/ 2.5

I have a 98 Subaru Outback w/ automatic tranny. It has 107K miles.
The check engine light came on about 1000 miles ago with Cyl. 2 and
Cyl. 4 Misfire trouble codes. The engine also started idling very
rough. I changed the platinum plugs about 4000 miles ago, so I think
they're probably good. When the light came on, I checked valve
clearance (it was in spec. according to the Haynes Manual) and replaced
plug wires. After replacing the wires, the engine was idling normally
and seemed to be alright. I cleared the engine codes and everything
seemed fine. The problem seemed to come back while returning from a
road trip....the engine was idling roughly and the check engine light
returned to haunt me.

Even though the coil pairs Cyl 1 & 2 and 3 & 4, I replaced it just to
be sure it wasn't the problem, but it's still there. The problem
doesn't seem to go away when the engine is cold, warm, or hot.

Why would it work fine for a while and then suddenly come back w/ no
changes?

I did take the timing belt off for the replacement of the oil seals @
the front of the engine about 4000 miles ago, but it didn't seem to be
a big problem when I put everything back together. I also pulled it
off about 1000 miles ago for checking the valve clearance. Is there a
possibility that there could be something going on w/ the timing, crank
sensor, or cam sensors, etc???

I bought a 1991 Honda Civic a little over a year ago when it had 120k
miles. At 130k it started knocking and there was no check engine light.
It only knocked when given too much throttle for a given engine speed,
but never in 1st gear. It definitely related to the load on the engine.
I assumed it was an ignition problem, and as part of my troubleshooting
I eventually coughed up the money for a timing light. I found my timing
to be way off and found the timing belt off by a tooth.

I guess what I am trying to say with this post is that your timing belt
could be installed improperly, and you may not even notice serious
driveability problems immediately. Since you were able to experience the
car with the belt properly installed, can you remember a decrease in
performance after you did the seal job?

P.S. - I took the car to a chain mechanic who rode with me around the
blocks a few times, and I made it knock for him. I don't know if he
could hear it or not, but he said some crap like, "That's what I should
expect for a car with that ind of mileage". BS

Mark

On Thu, 20 Jan 2005, Hallraker wrote:

> Seems that some mechanics are still stuck in the stone age, when it was
> amazing to get 60k out of a car without serious engine problems or a
> complete replacement. Honestly, any car made within the last 10-15 years
> should be capable of over 200k miles, given proper care and maintenence.

You must've been buying some rather crappy cars, back then -- if you were
buying any cars at all in the "stone age". Perhaps you bought VW Beetles,
or early Subarus, or early Toyotas, or a Chevrolet Vega (was there anyone
dumb enough to buy two?), or any of many other examples of engineering
mediocrity. Either that or you watch too many ads on TV.

Contrary to your implication, automotive durability did not suddenly
appear (boom!) in 1990. It didn't even become universal around that time.
In 1990, one could buy a Yugo or a Hyundai Excel or a great many other
cars wholly incapable of 200K miles even pampered and given heroic
maintenance. Guess what? You still can, right now, today! Hey, Subaru
didn't fix their piston slap problem in the 2.5 until Y2K when it was
redesigned for non-interference. But I digress. Y'ever hear of the
slant-6? How 'bout the 318? The 350Y? The 232, the 258, either of two
different-make 3.8s, The B16, the B18, the B20, the B30? All of those and
many others routinely made it well past 200K miles (before 1990!) with
nothing more than normal maintenance, even with yesterday's relatively
inferior oils, filters, etc.

It's a common error to believe that the dawn of engineering rectitude
coincided roughly with one's own birth, and that "newer" necessarily means
"better". Fortunately, there are plenty of counterexamples to this sort of
stinkin' thinkin'.

DS

I just had the chance to take the timing belt cover off to verify that
the belt is aligned properly w/ the cam pulleys and the crank pulley as
well as the marks on the timing belt cover, etc. It looks like
everything is lined-up perfectly! I was originally thinking that I
could have the belt off a notch or something, but I don't believe
that's the case. I've replaced the belt in the past and this looks
just like it should.

Has anyone with subaru experience seen this type of problem (Cyl 2&4
misfiring even after replacing coil, wires, etc)? Does anyone w/
Subaru experience have any ideas as to what I might be fighting?

Is there some kind of ignition module or other electronic component in
the ignition system that might be causing a misfire in cyl 2 & 4?

A misfire is anything that will prevent a cylinder to produce normal
power on combustion stroke. It's not necessarily electrical. Could be
the fuel injectors, the valves, or...
The only thing I can think of is that those two cylinders share a common
injector bank. Is that a clue?
If electrical it could be the igniter.
Good luck!

darealclemshady wrote:
> I just had the chance to take the timing belt cover off to verify that
> the belt is aligned properly w/ the cam pulleys and the crank pulley as
> well as the marks on the timing belt cover, etc. It looks like
> everything is lined-up perfectly! I was originally thinking that I
> could have the belt off a notch or something, but I don't believe
> that's the case. I've replaced the belt in the past and this looks
> just like it should.
>
> Has anyone with subaru experience seen this type of problem (Cyl 2&4
> misfiring even after replacing coil, wires, etc)? Does anyone w/
> Subaru experience have any ideas as to what I might be fighting?
>
> Is there some kind of ignition module or other electronic component in
> the ignition system that might be causing a misfire in cyl 2 & 4?
>
>

On Sun, 23 Jan 2005, darealclemshady wrote:

> Has anyone with subaru experience seen this type of problem (Cyl 2&4
> misfiring even after replacing coil, wires, etc)?

A very common cause of persistent misfire is as follows:

Misfire occurs due to secondary voltage leak down spark plug insulator to
ground. First component replaced is spark plugs, but plug wire boots have
also been affected, so affected plug boots continue to allow voltage
leakage. Misfire persists, so spark plug wires are replaced, but plugs are
left alone since they were just replaced. But, faulty plug boots caused
leakage path on plug insulators. Back and forth and back and forth. Often
a persistent misfire of this nature will go away when plugs AND wires are
replaced at the same time.

Daniel, that's a great point. This is exactly what I've done. I
replace the plugs, THEN the wires and now I've got my problem again (it
did seem to work fine for about a thousand miles though). Do you think
that since the misfire has started occuring again (maybe due to damaged
plugs?) that the new plug wires I recently put in (about 1200 miles
ago) might now be damaged and in need of replacement at the same time
as some new plugs?



Gilles Gour, Can you expand on the igniter a little bit? I haven't
seen it in the Haynes manual. Where is it, what does it do, and how
can it be tested/replaced?

Thanks for the input!!!

On Sun, 23 Jan 2005, darealclemshady wrote:

> Daniel, that's a great point. This is exactly what I've done. I
> replace the plugs, THEN the wires and now I've got my problem again (it
> did seem to work fine for about a thousand miles though). Do you think
> that since the misfire has started occuring again (maybe due to damaged
> plugs?) that the new plug wires I recently put in (about 1200 miles ago)
> might now be damaged and in need of replacement at the same time as some
> new plugs?

Yep, that is a distinct possibility. When the spark "leaks" down the side
of the insulator, it forms a conductive path on the insulator AND the
inside wall of the boot. Fixing half the problem (replacing the plugs OR
the wires) will generally reduce the leakage path's severity enough to get
you a thousand miles or so of good running, but it's not a long-term fix.
Replace the plugs AND the wires. Or, if you feel like trying to save your
almost-new components, wipe the plug insulators and swab the plug boots'
interiors THOROUGHLY with denatured alcohol (Q-tips work well for the
boots) until they are squeaky clean. Apply silicone dielectric grease
liberally to the plug boots, and reinstall everything.

> Gilles Gour, Can you expand on the igniter a little bit? I haven't seen
> it in the Haynes manual. Where is it, what does it do, and how can it
> be tested/replaced?

Vehicles with distributorless ignition do not use ignitors.

DS

Daniel J. Stern wrote:

> On Sun, 23 Jan 2005, darealclemshady wrote:
>
>
>>Daniel, that's a great point. This is exactly what I've done. I
>>replace the plugs, THEN the wires and now I've got my problem again (it
>>did seem to work fine for about a thousand miles though). Do you think
>>that since the misfire has started occuring again (maybe due to damaged
>>plugs?) that the new plug wires I recently put in (about 1200 miles ago)
>>might now be damaged and in need of replacement at the same time as some
>>new plugs?
>
>
> Yep, that is a distinct possibility. When the spark "leaks" down the side
> of the insulator, it forms a conductive path on the insulator AND the
> inside wall of the boot. Fixing half the problem (replacing the plugs OR
> the wires) will generally reduce the leakage path's severity enough to get
> you a thousand miles or so of good running, but it's not a long-term fix.
> Replace the plugs AND the wires. Or, if you feel like trying to save your
> almost-new components, wipe the plug insulators and swab the plug boots'
> interiors THOROUGHLY with denatured alcohol (Q-tips work well for the
> boots) until they are squeaky clean. Apply silicone dielectric grease
> liberally to the plug boots, and reinstall everything.
>
>
>>Gilles Gour, Can you expand on the igniter a little bit? I haven't seen
>>it in the Haynes manual. Where is it, what does it do, and how can it
>>be tested/replaced?
>
>
> Vehicles with distributorless ignition do not use ignitors.
>
> DS

Sorry Daniel, but my 96 Legacy has a distributorless ignition and has an
igniter. The igniter is the electronic component that triggers the
primary circuit of the ignition coil. On my car - and I think on most if
not all Subarus - the ignitor is in the middle of the firewall. The
wires going to the coil's primary circuit will lead you there.
On page 2-16 of the Chilton's manual in the «Distributorless ignition
system», one can read: «The Ecu receives signals from the airflow
sensor, water temp sensor, crank angle sensor, cam angle sensor, knock
sensor and other verious indicators to judge the operating condition of
the engine. It then selects the optimum ignition timing stored in the
memory and immediately transmits a primarun current OFF signal TO THE
IGNITER to control the ignition timing.»
I could give you the testing method for the igniter when I put my hand
on my Haynes manual. Chilton's does'nt give any.

Hmmmm My 98 Impreza outback is distributerless and it sure as heck does
have an igniter.


"Daniel J. Stern" > wrote in message
n.umich.edu...
> On Sun, 23 Jan 2005, darealclemshady wrote:
>
>> Daniel, that's a great point. This is exactly what I've done. I
>> replace the plugs, THEN the wires and now I've got my problem again (it
>> did seem to work fine for about a thousand miles though). Do you think
>> that since the misfire has started occuring again (maybe due to damaged
>> plugs?) that the new plug wires I recently put in (about 1200 miles ago)
>> might now be damaged and in need of replacement at the same time as some
>> new plugs?
>
> Yep, that is a distinct possibility. When the spark "leaks" down the side
> of the insulator, it forms a conductive path on the insulator AND the
> inside wall of the boot. Fixing half the problem (replacing the plugs OR
> the wires) will generally reduce the leakage path's severity enough to get
> you a thousand miles or so of good running, but it's not a long-term fix.
> Replace the plugs AND the wires. Or, if you feel like trying to save your
> almost-new components, wipe the plug insulators and swab the plug boots'
> interiors THOROUGHLY with denatured alcohol (Q-tips work well for the
> boots) until they are squeaky clean. Apply silicone dielectric grease
> liberally to the plug boots, and reinstall everything.
>
>> Gilles Gour, Can you expand on the igniter a little bit? I haven't seen
>> it in the Haynes manual. Where is it, what does it do, and how can it
>> be tested/replaced?
>
> Vehicles with distributorless ignition do not use ignitors.
>
> DS