Subaru Outback Forums banner
  • Hey everyone! Enter your ride HERE to be a part of this month's Outback of the Month Challenge!

1 - 20 of 30 Posts

·
Registered
Joined
·
18,795 Posts
Discussion Starter · #1 · (Edited)
Yesterday I experienced what seemed to be random misfires after starting the car on a cold (34F), damp (fine, misty rain) and foggy morning. The car had been parked overnight. It's a 2007, 2.5, N/A, automatic, with 74,000 km (44,000 miles), in service since December 06.

The misfires appeared less and less over time (warming up in driveway for about 45 seconds), but were still occasionally noticed as we drove out, slowly, to a nearby store, mainly while idling at a light. When we left the store, there was still the odd miss, and then the symptom completely disappeared within a few hundred feet (slow driving, pulling out of the parking lot). But then the CEL came on. (Not unexpected.)

Back home, the code reader indicated three codes: P0301, and pending codes P0301 and P0303. (Misfire on cylinder 1, and pending misfires on cylinders 1 and 3.)

The car has been driving perfectly since, and now having completed three full driving cycles (warm-up, driving at various speeds, cool down), the CEL has gone off, and the code reader is indicating only the P0301 (in memory). Again, not unexpected.

I spoke with the chief mechanic at my dealer by phone today, and as soon as I described the symptoms and conditions, he said it was the coil pack. This too wasn't unexpected, but he also indicated that it's common on this series of Subaru where the coil pack is mounted vertically on the back of the intake manifold, immediately above the engine block.

It's quite possible that there's a hairline crack in the coil housing and moisture caused the misfires until it was evaporated by engine heat. (I'll try to have a closer look.) It's also possible that the location of the coil makes it more susceptible to mechanical stress, and therefore cracking, because it isn't protected from engine block heat, at least to a degree, by the manifold (as is the case when the coil is mounted above the manifold).

However, I've been on the forum for several years now, and I don't recall there being any noticeable trend in the number of coil failures in the 2005-9 models.

Have I missed relevant posts, here or on other Subaru forums, and this is a common failure; or,

Have other members here experienced coil failures in their 2005-9 vehicles but haven't posted about them, at least not yet?
 

Attachments

·
Registered
2017 Touring (Canadian version) 2.5 in Ice Silver 15,000 kms
Joined
·
52 Posts
Plain OM

I too have had the coil replaced. And what was even more intereseting, while I was picking the car up after the replacement the service writer was taking a call for another coil pack. More common than we think.
 

·
Registered
Joined
·
18,795 Posts
Discussion Starter · #3 ·
MaryMonster

Thanks for the response. Add two . . . .

You're car is much "younger" than mine. When did the coil go out? Did you have the same experience in damp (Halifax) weather, or did it exhibit problems at other times?
 

·
Registered
2017 Touring (Canadian version) 2.5 in Ice Silver 15,000 kms
Joined
·
52 Posts
OM,

I had made a road trip to the Algonquin Park area (love Cottage Country by the way!) and had one CEL/Cruise occurrance on a wet day in October. I blamed it a hurricane which went through and thought nothing more about it as it cleared up as the car warmed up. Then in November it happened again so I made a quick left turn and headed to the local dealer. They pulled codes P0303 and P0304. They replaced the coil and wire set. That was at 38,832 kms so still under warranty.

Monster
 

·
Registered
Joined
·
18,795 Posts
Discussion Starter · #5 ·
Thanks for the response. 39k. That's really low. Almost makes me think I didn't do so badly!

I tried to have a look at the coil, in place, but couldn't spot any noticeable defects. I'll have a closer look when it's changed, Looks like I'm in for a few hundred $ on this one. I was thinking about doing it myself (looks pretty straightforward, albeit a bit tight working on the back of the manifold), but because the engine is still under warranty I'm inclined not to for now. Probably take it in early next week.

Any other readers have had to change theirs or know of people who have (2005-9)?
 

·
Registered
2003 Outback LL Bean bought w/163K and now has 235K Miles
Joined
·
79 Posts
While I have the previous gen subie, I can also see the possibility that there could be an issue with the wires and/or the connections of the wires to the plugs and coil.

With the high voltage generated, it is very easy to arc to ground, either thru bad wire insulation or connections at coil/plug that were not well sealed with dielectric grease.

I learned about this many years ago when I added an MSD ignition box to my car without upgrading the cap and wires. It was like the 4th of July under the hood with all the arcing! Lol!
 

·
Registered
2008 OB XT Limited; 2002 Impreza 2.5TS
Joined
·
1,398 Posts
This is news to me.

I was under the mistaken assumption that modern ignition systems were basically flawless and maintenance free...
 

·
Registered
My sons 2000 Outback
Joined
·
212 Posts
Generally speaking...Bad /old wires is the primary reason for misfire crappy running car until Warm up can dry everything out.
run the car in the dark and spray water from a Spray bottle ( Windex bottle) at the wires and see if you get sparks from Wires to Engine block or Wire to wire.
 

·
Registered
Joined
·
18,795 Posts
Discussion Starter · #9 ·
This is news to me.

I was under the mistaken assumption that modern ignition systems were basically flawless and maintenance free...
Same here. My previous car, which I bought new, had a 17 year life and went over 200,000 miles on the same coil, wires, and distributor cap, and never exhibited any problems, so I guess I'm somewhat biased by that experience.
 

·
Registered
Joined
·
18,795 Posts
Discussion Starter · #11 ·
I've since come to the conclusion that the mechanic was responding from one perspective -- the cars he sees. As such, among all the problems he has dealt with, the coil might come high on the list. In this regard, I also found that there was a problem with the coils a few years ago, especially on the Foresters -- moist condition-misfires were indeed common.

I decided to replace the coil and wires myself. The coil and the wire set are Subaru-packaged parts from the dealer, but aren't the same as the original factory parts.

The original coil is p/n 22433AA50A, the new one is 22433AA580. The former is listed on the http://opposedforces.com/parts/ website, whereas the latter shows up in current, on-line dealer oem catalogs. Looks as if there was a change since the car was assembled in Sept 06.

Also, the original wires are Packard with resistive cores, whereas the replacements are NGK silicone "mag-cores". (See http://www.subaruoutback.org/forums...5-liter-n-spark-plug-wires-resistive-not.html)

I did find a small "pin-prick" indentation in the outer shell of the original coil, on the flat bottom side of the #3-4 coil area. I can't tell if this goes right through the black outer shell to the coil inside, but if it does, that could well be the problem.
 

·
Registered
2017 Outback 2.5i Limited
Joined
·
62 Posts
Hey Plain OM hope the bad mojo from my 2000 ignition coils didn't jump the border and get to the Gen3's. Thanks again for all the help with mine when I was having issues with the coils going bad. Fingers crossed- it's been running well.

But I can't help but notice the similarity in issues you were having with the misfires after the car sat out in chilly damp over nights. That was similar to mine each time it was misfiring and subsequently blowing the coils.

I will say that i couldn't see any evidence of dielectric grease on my plugs, wires or coil from the times that i had issues. With the coil I got for the scrap yard, I cleaned the contacts and added dielectric grease to both ends of wires and so far so good- 3 weeks and counting. Be sure to have the grease on them.

Good thinking to take it in under warrantee then it will be on the dealer if anything happens to go wacky in the future.

Good luck with everything.
 

·
Registered
Joined
·
18,795 Posts
Discussion Starter · #13 ·
hope the bad mojo from my 2000 ignition coils didn't jump the border
Probably not. The "pin-prick" indentation I found is the likely culprit. However, that said, i am keeping in mind your finding of possible conductive traces in the main engine harness-to-bulkhead harness connector. I didn't open mine, mainly because I didn't want to risk upsetting the gasket (if my 07 has the same arrangement), but also because I was puzzled by how the mating connectors fit together. They seem to be held in a separate frame that has slots in the side, sort of suggesting that the mated connectors pivot up and then are disconnected. Was your's the same, and if so, how do they come apart? (If this isn't clear, post back and I'll see if I can get a good photo.)

I did apply a thin film of dielectric grease on the inside surface of the rubber boots.
 

·
Registered
OB2.5i, CRXSi
Joined
·
22 Posts
I have 2005 OB 2.5i and I had the EXACT same symptoms. The CEL light would light up on misty mornings. Dealer replaced the coil around 45k miles (about 2 years ago).

Now the car has 68k miles, the same thing happened few weeks ago. CEL light came on, I disconnected the battery and it went away.
Few days later the car started to shudder and lose power under acceleration. Now it does this all the time. But no Check Engine Light. The car is drivable, but I definitely need to get this resolved.

and Bimmer, you're right I never had to change coil pack on any of my other cars that I've owned for over 6 years and over 120,000 miles...
 

·
Registered
My sons 2000 Outback
Joined
·
212 Posts
I have 2005 OB 2.5i and I had the EXACT same symptoms. The CEL light would light up on misty mornings. Dealer replaced the coil around 45k miles (about 2 years ago).

Now the car has 68k miles, the same thing happened few weeks ago. CEL light came on, I disconnected the battery and it went away.
Few days later the car started to shudder and lose power under acceleration. Now it does this all the time. But no Check Engine Light. The car is drivable, but I definitely need to get this resolved.

and Bimmer, you're right I never had to change coil pack on any of my other cars that I've owned for over 6 years and over 120,000 miles...
Was it old Ignition wires or a bad Coil?

My son just started experiencing a misfire on his '00. We do not have any history on the last Wire and Plug change so that will be first on the list to remedy this.
 

·
Registered
OB2.5i, CRXSi
Joined
·
22 Posts
Based on my research, it can be anything from a bad coil pack, o2 sensors, catalytic converter, or anything along the ignition system...

Anyway, I've had enough of this car and I'm sorry to say that I have traded this 05 Outback for a Honda.

This 2005 Outback has made its mark as the most troublesome, highest maintenance car I have ever owned... =(

Luckily, the resale value on these cars are awesome right now...!
 

·
Registered
07 OBW 2.5i Limited, 02 Audi A6 3.0 Avant Quattro
Joined
·
981 Posts
Same thing for me. Dealer replaced 1 coil and 1 plug wire due to steady CEL + blinking cruise green light. No charge w/50k mi. I have Gold+ extended warranty $100 ded. but dealer didn't charge me any, so I am happy.
 

·
Registered
'08 OB 2.5i MT
Joined
·
257 Posts
Started getting misfires with CEL in Cyl 2 couple of weeks back on my 08 (115K). Changed plugs, was OK for a little while but misfires came back. Same symptoms as plain OMand 05scooby.

plain OM and others who replaced coil packs - did it solve the problem?
 

·
Registered
Joined
·
18,795 Posts
Discussion Starter · #19 ·
In my case, the misfire symptoms, as reported in post #1 above, went away after a few minutes.

I subsequently replaced both the wires and the coil, but since then the car hasn't been parked in the same situation (cold, damp weather).

The CEL went out on its own after a few driving cycles, but the code remained stored in the memory until recently, when it was erased automatically because there was no further sign of problems.

If the misfire appears when it's very damp and there might be moisture on the surface of the coil or wires, the problem more often is wires or the coil, not the plugs. If a plug is defective its's more likely to show symptoms regardless of the weather. A plug will also misfire if the valve cover gasket seal around the spark plug tube is leaking and oil gets on the plug. When the spark plug wire is pulled out from the tube, check for oil on the extension (the part inside the tube) and in the tube itself.
 

·
Registered
'08 OB 2.5i MT
Joined
·
257 Posts
Replaced Spark Plug Wires

Started getting misfires with CEL in Cyl 2 couple of weeks back on my 08 (115K). Changed plugs, was OK for a little while but misfires came back. Same symptoms as plain OMand 05scooby.

plain OM and others who replaced coil packs - did it solve the problem?
... and it seems to have done the trick :29:. Hesitation and misfiring is gone and CEL is steady with flashing CRUISE. Will see if this clears by itself in few days.
 
1 - 20 of 30 Posts
Top