2009 Subaru Forester Spark Plugs

[Phishin]

My wife currently has 51k on her Forester. Her car has the natural aspirated 2.5L H4 engine. Subaru says to change the plugs every 30k miles. But I see most think it's a waste to do so, plus, they are kind of a pain in the rear to change. I'm thinking of changing them this fall. Good idea? Or wait until she hits 70-80k miles on it? Do you Subaru guys all recommend OEM plugs or something different? Thanks in advance.

 

[Rand]

It depends on if your car has the copper plugs or platinums. I dont remember which came with coppers but they were pretty done at 30-40k. If it has platinum 60k miles is quite reasonable for an interval. Edit: I think the 30k interval was for turbo engines. for N/A 60k miles is fine. but its based off the spark plug type. also watch out that the replacements are the same heat range... if you go to a place that has counter tards.(ie the new o'riellys near me where 3/4 the employees know practically nothing.)

 

[sicko]

I believe the non-turbo are listed as 30k, and the turbos are yuk for the Foresters. NGK was the OEM spark plug in your Forester, so I suggest sticking with NGK plugs.  I put NGK Iridiums in my Subaru and haven't had any issues with them.  It's an easy enough job to do yourself on your Forester.  On the passenger side you just need to remove the air intake, and on the driver's side you just need to remove the battery to get access to everything. I highly suggest getting the Gear Wrench 5/8" x 6" Magnetic Swivel Spark Plug Socket, or something similar to it.  It made the job so much easier when I recently did the plugs. 

 

[Rand]

Originally Posted By: sicko

I highly suggest getting the Gear Wrench 5/8" x 6" Magnetic Swivel Spark Plug Socket, or something similar to it.  It made the job so much easier when I recently did the plugs. 

AAP has it for 11$ its 18 on amazon.

 

[waltb]

I have a 2008 Outback with the same engine. I did the 30k spark plug replacements when in warranty. It is not that hard to replace the plugs unless the Forester is significantly different than the Outback. There were NGKs installed OEM. I have used NGKs, Denso's and Autolite double platinums. The NGKs and Autolites both seem to work fine at least in my car. They come out almost looking like new. The one time I tried Denso's they came out looking quite worn out. Now that my car is far out of warranty I am leaving the current batch of Autolite double plats in for 60K miles since it seemed to be waste to keep changing plugs at 30K when they were barely worn. p.s. It is interesting but the same spark plugs that fit the Subaru also fit my Toro lawn mower. So the mower gets the hand me downs. wb

 

[05LGTLtd]

If your car has double platinum plugs stock, stay with those. I'm pretty sure our 2010 Foz did. I need to change them again. Apparently switching to iridium has the potential to cause problems because of the way the spark current is regulated/generated. NGK Double platinum. They are not that hard to change. Small hands help, but just go to lowes and buy a 3" wobble extension. You'll wonder how you ever lived without one of these: http://www.lowes.com/pd_10171-1074-22894_4294857618_4294937087?productId=1210313 Looks like lowes may have disc these, but you can find them other places. 3" with spark plug socket is perfect. If you have a 3/8" Universal and a 1" extension, that works too. While your in there tinkering, change the PCV valve out too. Not too hard, pull the plastic air intake (good time to clean maf and change air filter) and the PCV pull up off the block. You can get just the PCV at NAPA stores. You'll need a vise/wrench to get the valve of the little block it sets in.

 

[LoneRanger]

Page 11-18 of the owner manual for my 2009 Forester (non-turbo, EJ253 engine) states the recommended spark plug is NGK FR5AP-11. Based on the below from NGK the FR5AP-11 is a double platinum plug: NGK website parts finder pulls up several types, and lists the FR5AP-11 as "Laser Platinum" to which it comments in the foot notes: * “Laser Series” Platinum center electrode, and Platinum pad ground electrode # Original Equipment Manufacturer, and/or Original Equipment Service Part http://www.ngksparkplugs.com/products/spark_plugs/laser_platinum.asp I have the factory service manual. It specifies tighten spark plugs to 21nm or 15.5 lb-ft. Supposedly no anti-seize need be used on NGK plugs, but this should be confirmed.

 

[tommygunn]

Wow 30k service interval for double platinum? Even copper plugs should be good for 30k! Is there an iridium plug that fits your engine? Because those should be good for 100k, Denso Iridium Long Life or NGK Laser iridium. Bosch and Champion also make affordable iridium spark plugs, and Champion is on rebate now.

 

[Vikas]

Double platinum has no problem lasting over 100K miles.

 

[dave5358]

Originally Posted By: Phishin

My wife currently has 51k on her Forester. Her car has the natural aspirated 2.5L H4 engine. Subaru says to change the plugs every 30k miles. But I see most think it's a waste to do so, plus, they are kind of a pain in the rear to change. I'm thinking of changing them this fall. Good idea? Or wait until she hits 70-80k miles on it? Do you Subaru guys all recommend OEM plugs or something different?

Change them. Try NGK FR5AP-11 #5463 platinum plugs. Look on eBay or Amazon for the best price. These plugs have both platinum center electrodes and platinum ground pads, which works out nicely with the wasted-spark ignition system used by Subaru. It's a PITA to change the plugs on any Subaru. Go over to Subaru Forester Org. There are numerous threads on changing plugs. The "issue" is that the vehicle frame prevents easy access to the plugs - it's even worse on the turbo cars. At a minimum, remove your air intake completely and remove your battery. For DOHC turbo cars, with re-designed 'thicker heads', it really helps to remove the 2 motor mount nuts and jack one side of the engine, change plugs, repeat on other side. Non-turbo cars are a slightly better (key word "slightly").

 

[skyactiv]

I own an 07' WRX which I bought new. It came with NGK Iridium plugs from the factory. My owners manual says to replace them every 60K. I did so with slightly more miles and they still looked new. Changing the plugs isn't difficult if you have the right tools. The hardest part about the job is removing the rear drivers side ignition coil; you gotta rotate and contort it while removing/installing it.

 

[artificialist]

Before buying your spark plugs, check for any TSB related to spark plugs. Sometimes the car manufacturer will decide to use different spark plugs as time goes on. I remember with my Saturn ION, it came with ACDelco double platinum plugs, but all replacement plugs were iridium. When I needed to change spark plugs on dad's 1997 Lexus ES300, a simple iridium plug replaced the weird dual electrode plugs, and were far less expensive.

 

[LoneRanger]

I poked around and found this:

 

[LoneRanger]

Further poking around finds the following which contradicts Subaru of America Tech Line's statement about platinum core vs copper, see #5 in NGK's list of "Five Things You Need to Know About Spark Plugs": http://www.ngksparkplugs.com/pdf/dyk_5points.pdf #5 says all NGK plugs use a copper core. I'm going to go with NGK knowing what core is in the OE plug better than SOA knowing, since NGK makes them. So... I'm still in the 60,000 mile camp for the non-turbo, double platinum tipped, OE plug.