Jump to content
LegacyGT.com

Check out my spark plugs please?


Recommended Posts

As the title says, what do you guys think of my spark plugs?

 

additional info: I've been getting intermittent misfire CEL on 4 (only when engine is barely semi-warm during idle). When fully warmed up, idle is OK but not that great IMO (rpm goes between 735 and 750).

 

Plug 4 looks to me carbon fouled. This apparently means, according to the manual, that it is mostly caused by slow speed driving in the city, weak ignition, too rich fuel mixture and dirty air cleaner. I do confirm that my air cleaner is indeed filthy (K&N that I am going to get rid off). I drive the car like 3 times a week and it is usually city stuff...

But if the plug is indeed carbon fouled, why would I get just ONE plug in such condition and not all of them?

 

And no, have not done compression/leak down tests. Can't find a place nearby that can do it :mad:.

 

Oh and I installed a brand new injector last week on #4.

FLS_7296.thumb.jpg.91851670dee15191d511591c7a150da1.jpg

FLS_7297.thumb.jpg.d61204f6b3e6baf9c232e50e7dd99acf.jpg

Link to comment
Share on other sites

I got one at Autozone that I've been using for years.
[URL="http://legacygt.com/forums/showthread.php/proper-flip-key-interesti-159894.html"]Flip Key Development Thread[/URL] "Genius may have its limitations, but stupidity is not thus handicapped." - E. Hubbard
Link to comment
Share on other sites

FYI, OP is in France...

 

Yeah. I am there for another few months with the OBXT. I just couldn't believe none of the 6 different shops (including the local bubble gum Subaru dealer) were doing compression test!

 

So back to the spark plug analysis. What do you guys think?

Link to comment
Share on other sites

I'm thinking they don't look that bad. May a little less light brown color would be ideal.

 

To me they don't look oil fouled or to lean.

 

Have you replaced the o-rings at the intake manifold to TGV's yet ?

305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

Engine Build - Click Here

Link to comment
Share on other sites

I'm thinking they don't look that bad. May a little less light brown color would be ideal.

 

To me they don't look oil fouled or to lean.

 

Have you replaced the o-rings at the intake manifold to TGV's yet ?

 

I do think they look OK as well but don't understand why #4 is darker than the others. I can add that they are definitely all dry (no presence of wet oil residue).

 

Haven't done the o-rings yet. I'll probably prepare a 'shopping' list and ask BMB his help to get the parts. :hide:

Link to comment
Share on other sites

hey xt how hard was it to change the plugs? it just looks lik a bitch to get to them.

 

You know? It was not that hard at all. It was just time consuming. One of the best tip IMHO: in order to get coil packs #3 and #4 out, make sure you turned them 180 degrees. Then you pull them out. For the whole job, I just used a 3/8 inch ratchet, 12mm 6 point socket, a short extension, and the spark plug socket. I did use a swivel joint at one point but you don't have to.

Link to comment
Share on other sites

You know? It was not that hard at all. It was just time consuming. One of the best tip IMHO: in order to get coil packs #3 and #4 out, make sure you turned them 180 degrees. Then you pull them out. For the whole job, I just used a 3/8 inch ratchet, 12mm 6 point socket, a short extension, and the spark plug socket. I did use a swivel joint at one point but you don't have to.

 

did you replace the coil packs as well?

Link to comment
Share on other sites

wat plugs did you replace them with and can we put the one step colder plugs in our lgts?

 

There is no reason to use a colder plug in a street driven Subaru.

 

Use OEM or NGK plugs.

[URL="http://legacygt.com/forums/showthread.php/proper-flip-key-interesti-159894.html"]Flip Key Development Thread[/URL] "Genius may have its limitations, but stupidity is not thus handicapped." - E. Hubbard
Link to comment
Share on other sites

There is no reason to use a colder plug in a street driven Subaru.

 

Use OEM or NGK plugs.

 

good to know. I just saw them from a vendor on here nd wondered if it would help throwin them in or not. do you kno if it makes a difference between using the ngk laser iridiums nd the regular iridium plugs?

Link to comment
Share on other sites

If you haven't replaced them yet, just swap coils between 2 and 4 and see if the misfire moves. You can do this regardless of the compression check. If it stays on 4 then try swapping injectors between 2 and 4. If it stays then it's either a bad electrical connection or something in the cylinder.
Link to comment
Share on other sites

  • Moderators
I do think they look OK as well but don't understand why #4 is darker than the others. I can add that they are definitely all dry (no presence of wet oil residue).

 

Haven't done the o-rings yet. I'll probably prepare a 'shopping' list and ask BMB his help to get the parts. :hide:

 

Seriously, send me a list of part numbers and I'm happy to pick stuff up for you.

"Bullet-proof" your OEM TMIC! <<Buy your kit here>>

 

Not currently in stock :(

Link to comment
Share on other sites

Seriously, send me a list of part numbers and I'm happy to pick stuff up for you.

 

thanks a lot man. I appreciate it. I may contact you if I can't get parts shipped directly to me.

 

A little update: I may add that the rough idle now occurs with an either cold, semi-warm, or at operating temp engine. This, to me, rules out intake manifold gasket issues, especially knowing that temperatures here are around 45-55F. I can tell I also miss a bit when I get it into boost.

Extra info:at idle, timing advance is oscillating between 5 and 15 degrees, trying to reach the 12 degree target.

 

 

If you haven't replaced them yet, just swap coils between 2 and 4 and see if the misfire moves. You can do this regardless of the compression check. If it stays on 4 then try swapping injectors between 2 and 4. If it stays then it's either a bad electrical connection or something in the cylinder.

 

^ yeah. So until I can buy a compression tester and some carb cleaner, I will swap coil packs and see if the misfire will follow. Injector on #4 is brand new.

Link to comment
Share on other sites

good to know. I just saw them from a vendor on here nd wondered if it would help throwin them in or not. do you kno if it makes a difference between using the ngk laser iridiums nd the regular iridium plugs?

 

Use what the car calls for. You'll be happy you did when you read the post by people who didn't.

 

FWIW, My wagon has one step colder and runs fine, but I know I have a great Tuner.

305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

Engine Build - Click Here

Link to comment
Share on other sites

  • Moderators
thanks a lot man. I appreciate it. I may contact you if I can't get parts shipped directly to me.

 

Even it it's just because it save you a couple bucks, just let me know. I pretty much always have a reason to stop by the autoparts store, the dealership is close enough, and I'm at a post office a couple times a week on average. Just FYI though, the flat rate boxes at USPS have gone up quite a bit for international stuff--not sure what the rate is to France so you would want to look that up :)

"Bullet-proof" your OEM TMIC! <<Buy your kit here>>

 

Not currently in stock :(

Link to comment
Share on other sites

Even it it's just because it save you a couple bucks, just let me know. I pretty much always have a reason to stop by the autoparts store, the dealership is close enough, and I'm at a post office a couple times a week on average. Just FYI though, the flat rate boxes at USPS have gone up quite a bit for international stuff--not sure what the rate is to France so you would want to look that up :)

 

thanks for the info. I will look that up for sure.

 

 

Update: well, just swapped coil packs and.....misfire is still there (on #4). So problem is neither due to coil pack, spark plugs, nor injector. Left with valves or ringland failure :(. I doubt its the IM gasket cause it's not cold over here.

 

I found a shop who let me borrow their compression tester! But it is not what I was expecting: the tip of the probe does not screw where the spark plug goes. You have to push and hold it while you perform the test...

Link to comment
Share on other sites

Any other feedback as to why only one spark plug is (dry) carbon fouled :redface:? Cause apparently the ignition and fuel systems are fine. So we're left with valves and ringland but manual says spark plug should be wet :confused:.

Question is: can issues with valves result in a dry carbon fouled spark plug?

 

Still have to wait to be able to do a compression test. Weather is awful over here and I don't have a garage.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.



×
×
  • Create New...

Important Information

Terms of Use