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2005 Forester manual
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93 Posts
Discussion Starter #1
I am going go to replace my spark plugs and I was looking for the type of plug I should replace them with. It doesn’t look to hard of a job, but any hints would be useful.
Thanks.
 

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Super Moderator
2007 Forester Sports XT 4EAT
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35,937 Posts
I'd go to the NGK website & plug in your vehicle information to see what spark plug fits. I'd recommend an iridium spark plug, which will last for 60K miles. They are a bit on the spendy side. :frown:

Some say it's easy to install spark plugs, some say it's hard. I bought my own spark plugs on eBay & had my trusted dealership install them for $100. :wink:

Bobby...

['07 FSXT MODding Journal] ['03 X MODding Journal]
 

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2007 Mitsubishi Pajero 5spd Automatic
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3,594 Posts
me and a friend of mine used 1.5hour to change them from the time I turned off the engine. Meaning it was kinda warm to touch :biggrin:
I Use NGK's iridium plugs too
 

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2017 Foz 2.5i CVT
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1,784 Posts
Are Iridium plugs in an NA engine gonna give me 60k?

I'm coming up on 30k miles and the first required plug change on my '09 X.

OEM plugs per the NGK site are the Laser Platinums which is what I'm assuming the dealer would normally stock.

The NGK also lists the Iridium IX plugs. Am I gonna be able to count on a 60k plug life with these?

I have some Subaru bucks to use so I may have the dealer do the plugs if my back is messed up at that point, but if I do them myself, should I try the Iridium plugs?

We've had cars as old as my wife's prior 1998 Sable with 100k plug change interval so I wonder why Subaru doesn't just use the Iridiums in the NA motor with a longer change interval.

George
 

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The Modfather
2016 BRZ Limited - Manual 6 Speed Manual
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8,095 Posts
I'm not sure a turbo vs NA is any more difficult, both are a PITA no matter how you slice it compared to most types of in line 4. I've never jacked up the motor on mine to change the plugs. Sometimes it's tougher to get the spark plug cable's boot off of the plug than it is to remove the coil pack IMHO. In particular if the previous install did non include using dielectric grease on the spark plug. If the spark plug boot is stuck on there and you have to pull so hard the cable snaps, it's a major PITA to get the boot out of there.
 

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2007 Mitsubishi Pajero 5spd Automatic
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I did not jack up the engine. But ye it's not much room. right set of tools and small hands I think helps alot.
 

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2015 Forester X 6MT 6-Gear Manual
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I'm coming up on 30k miles and the first required plug change on my '09 X.

OEM plugs per the NGK site are the Laser Platinums which is what I'm assuming the dealer would normally stock.

The NGK also lists the Iridium IX plugs. Am I gonna be able to count on a 60k plug life with these?

I have some Subaru bucks to use so I may have the dealer do the plugs if my back is messed up at that point, but if I do them myself, should I try the Iridium plugs?

We've had cars as old as my wife's prior 1998 Sable with 100k plug change interval so I wonder why Subaru doesn't just use the Iridiums in the NA motor with a longer change interval.

George
I still dont see any need AT ALL to replace double platinum OEM plugs at 30K on the NA motor. NONE. Somebody give me a reason. Ignoring what the rec service interval is. Dealer moneymaker ONLY. These are 60K easy plugs. I think subarus is the only MFG on the planet recommending 30K service on a double plat plug in a NA engine.
 

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2015 Forester X 6MT 6-Gear Manual
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I feel Ir with fine wire center electrodes are for COP ignition or dist only - I would not put them in a double ended resonant coil (NA motor) since they do not provide for negative firing (GND to center) as this layout requires.
 

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2007 Mitsubishi Pajero 5spd Automatic
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I still dont see any need AT ALL to replace double platinum OEM plugs at 30K on the NA motor. NONE. Somebody give me a reason. Ignoring what the rec service interval is. Dealer moneymaker ONLY. These are 60K easy plugs. I think subarus is the only MFG on the planet recommending 30K service on a double plat plug in a NA engine.
I agree with you. Replacing those at 30k is too early.
 

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The Modfather
2016 BRZ Limited - Manual 6 Speed Manual
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I still don't see any need AT ALL to replace double platinum OEM plugs at 30K on the NA motor. NONE. Somebody give me a reason. Ignoring what the rec service interval is. Dealer moneymaker ONLY. These are 60K easy plugs. I think subarus is the only MFG on the planet recommending 30K service on a double plat plug in a NA engine.
Well, because they are not, see attached:

That info is in my link I posted above...
 

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The Modfather
2016 BRZ Limited - Manual 6 Speed Manual
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I just replaced the plugs on my wifes B9 at almost 60K they were in good shape too. I mean they looked like they were wearing well. I suppose the point of intervals is not to let them get to the point of needing to be replaced. They also happen to be the same plug that go in my F-XT so I have another 4 sitting on my work bench waiting to be installed...
 

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I replaced the plugs on my 06 NA last weekend at 60K miles. They looked similar to Peaty's images above. I think it was time to replace them. I'm not sure the car ran any better after the replacement, but they did have some wear on them. Good preventative maintenance.

I was a bit apprehensive about changing the plugs due to all the 8 hour sagas described on this forum. For my non-turbo, it was easy. Probably took me about an hour. It is really useful to remove the battery, as well as the air filter housing. It takes 10 minutes or so to take out the battery, but makes so much more room to work.

Why don't people look in their owner's manual for the correct spark plugs to use?
 

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Super Moderator
2007 Forester Sports XT 4EAT
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Why don't people look in their owner's manual for the correct spark plugs to use?
That would be the place to start, but there are options, like this for your '06. :wink:

From what I'm hearing, the factory installed plugs in a nonturbo engine changed at the recommended 30K miles show little wear & when changed at 60K miles, they show wear, but still look pretty good.

The spark plug change for the turbo engine is 60K miles using iridium spark plugs. I'd guess they's be looking pretty good at 120K miles, not that I'd push them out that far.

We installed NGK IX irridium spark plugs in our '03 X recently. For the longer life & the MODding we've done to the engine. :smile:

Bobby...

['07 FSXT MODding Journal] ['03 X MODding Journal]
 

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2008 2008 2.5i-2018 XT
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It is really useful to remove the battery, as well as the air filter housing. It takes 10 minutes or so to take out the battery, but makes so much more room to work. ?
I removed the battery but found it wasn't really necessary. Did my daughter's car a couple weeks later and didn't remove it. Removing the air box is mandatory.
 

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2005 Forester
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I did mine today it really wasn't bad. You must remove the air filter box and hose. Work the passenger side first. You need two three inch extensions a 5/8 spark plug socket an 8mm a 12mm and a 8 or 10 extension. My 5/8 spark plug socket had a swivel on it bu an additional one for the drivers side will hep. is a little more difficult but I was able to get it done. Good luck!
 
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