Subaru Forester Owners Forum banner
1 - 3 of 3 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter · #1 · (Edited)
Situation:

My '04 Forester is lagging/chugging a bit. I put in some premium and replaced the fuel filter when the chugs began (70kish miles on the fuel filter? It looked OEM so it might be more like 123k on it. No codes were thrown.

It started to fart a bit after and by time I attempted to leave this morning codes were thrown and it shook like a slow martini. I'm thinking I need plugs and wires and that should solve it. I've looked around the forum and decided I should attempt to swap my wires as well as this may be a cam issue (or even just the o2).

Questions:

Where should I start, what's the cheapest beginning that I could do at my house?
Am I overlooking a step that could save me both time and money?
Thanks in advance for your knowledge and help!

-----

Updates:
  1. I attempted the idle relearn that's posted on the forums a moment ago; however, it threw a flashing CEL for 2 and 4 so I shut it down instead of letting it idle to try and fix the issue.
  2. Tested ohm resist on coil, 1-2 appears within normal bounds of 8.5 while 3-4 is flat. Was going to replace the coil; however, it was $110 locally without the possibility of return.
  3. Pull all the plugs to see if they were bad.

Upcoming steps:
  1. Change park plugs & wires (Likely the culprit)
  2. Vacuum leak check (Seems unlikely at the moment)
  3. Inspect timing belt (Jump?)
  4. If 2 and 3 checks out, ignition coil. (more likely than 2 and 3 but less likely than 1)
  5. Test injectors & perhaps pull fuel rail. (god I hope not)
Solution:
I pulled the plugs to check them, most were .06 - .085 copper champion garbage. All look good except one (4) which was BLACK. Replaced all four sparks for $3.5 each, using copper lock and dielectric grease. I took some time to clean a few things under the hood, some for show, some for mechanics.

Started right up without any CEL and allowed the ECU to relearn the idle per the forums post on subaruforester that's floating around. Took it for a drive and boy was it SNAPPY. :)
 

·
Registered
2004 Forester XT 5M (Man-hwel)
Joined
·
41 Posts
Just a word of caution before you exhaust all your inexpensive swaps(they add up!) and pull your hair out chasing a misfire around in the electricals....consider a compression test starting with #4. I just went through all of that over the course of a year. Not to scare you, but I'm looking at either a used engine swap or selling the car in my case ;(

Mike
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #3 · (Edited)
Just a word of caution before you exhaust all your inexpensive swaps(they add up!) and pull your hair out chasing a misfire around in the electricals....consider a compression test starting with #4. I just went through all of that over the course of a year. Not to scare you, but I'm looking at either a used engine swap or selling the car in my case ;(

Mike

Yikes! I'll keep that in mind. It's a bummer if that's the case, I'm only at 123k miles.

I just resistance tested my coil in a lazy way, looks like 8.5 in the 1-2, with a reading of 0 on 3-4. Granted I didn't roll over the car with a light test and that's not the best way to test it...but I think that warrants a quick swap of the coil to see if anything improves or changes. I can also take it back if it's a non-issue. One of the posts (3 specifically) was green as it was very corroded; however, that's not the misfire cylinder.

hmmmm, the hunt continues. When/if I figure this all out I'll post updates and a follow-up so others may benefit.
 
1 - 3 of 3 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top