[AlleyCat]

Couple questions:
1) What was Year and Model, Engine of car serviced
2) What plugs came out ( Make and part#)
3) What plugs went back in
4) Did it run any different afterwards with the Autolites, and how close was the autolite insulator length to the NGK/ND - critical for a pent roof 'hemi' head.

thanks Al.

 

[EvilDan]

My parent's old oldsmobile V6 was also a pain to change plugs on.. the front facing 3 were easy, the rear were right up against the firewall. You had to disconnect an engine mount and lean the engine towards to front to give yourself SOME room.. but still not enough to need new knuckles.

 

[adc]

Couple questions:
1) What was Year and Model, Engine of car serviced 2008 N/A
2) What plugs came out ( Make and part#) NGK FR5AP 11
3) What plugs went back in Autolite AP3924
4) Did it run any different afterwards with the Autolites, and how close was the autolite insulator length to the NGK/ND - critical for a pent roof 'hemi' head. Seems to run just the same. The length of the insulator/ground prong appeared the same but I didn't measure them

thanks Al.

Good Questions. You are welcome

 

[2.5x_sleeper]

The spark plug tightening torque for my '03 X is 15.2 ft-lb. The instructions say this is for a new, dry (no lubrication) spark plug. If lubricated, the torque is to be reduced by 1/3, which makes the torque 10.2 ft-lbs.

Bobby...

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

 

[Lovesubaru]

Great write up and photos
Thanks for such great info you provide


BTW, what's wrong with anti-seize???

 

[adc]

BTW, what's wrong with anti-seize???

There is just controversy as to using it or not.. As pointed out above you need to reduce the torque. I have seen info that some plug manufactures don't want lube on threads.

The spark plug tightening torque for my '03 is 15.2 ft-lb. The instructions say this is for a new, dry (no lubrication) spark plug. If lubricated, the torque is to be reduced by 1/3, which makes the torque 10.2 ft-lbs.
]What instructions are these[source]?..I'm not doubting you[/B]

Is using anti-seizing compound considered lubricating the threads?
I would say 'yes'

Bobby...

 

[2.5x_sleeper]

Here's my source, Subaru Technical Information, which is for '03-'04 N/A engine. :smile:

Bobby...

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

 

[2.5x_sleeper]

BTW, what's wrong with anti-seize???

Absolutely nothing wrong with using anti-seize compound, especially when putting a steel spark plugs into aluminum heads. The anti-seize compound will prevent seizing, which could damage the threads on the softer aluminum heads. This used to be a major problem on older VW bugs. I had to have helicoils installed on the heads after seized spark plugs pulled out the aluminum threads. :frown:

Of course if you use anti-seize compound, you need to reduce the specified torque by 1/3. :smile:

Bobby...

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

 

[vintage42]

There is just controversy as to using it or not.. As pointed out above you need to reduce the torque. I have seen info that some plug manufactures don't want lube on threads.

I would always use anti-seize. There is no harm in doing so, and great potential harm if not done.

On my vintage BMW motorcycles, constant removal and replacement of dry plugs galls the threads over many years, making the plugs loose in their threads, eventually requiring expensive head repairs.

At the other extreme, on my brother's 1990 Mazda truck, one dry plug became stuck on removal at 60K miles, so he left it in. He was then afraid that if it was ever removed, a new plug could not be inserted past the carbon build up on the head threads. The plug was still like that when he sold the truck at 150K.

I always use anti-seize on plugs, and tighten with a small socket wrench until I feel the gasket begin to compress. And change car plugs at 30K miles.

 

[adc]

Just to report back. The Autolite Plats ($1.99) gave me the best mileage I have had thus far on the car. (32.4 mpg) now that was over only 250 miles but the other part of the trip included 40 miles of driving inside the Pittsburgh area and my overall trip mileage (474 miles) averaged 31.2 mpg). I intend to pull the plugs at 20K miles just to examine them. But this is the 4th vehicle I have had them in.

Changing them the second time will be a piece of cake...1.5 hours.

Autolite#..AP3924

 

[Real Lyte]

Just to report back. The Autolite Plats ($1.99) gave me the best mileage I have had thus far on the car. (32.4 mpg) now that was over only 250 miles but the other part of the trip included 40 miles of driving inside the Pittsburgh area and my overall trip mileage (474 miles) averaged 31.2 mpg). I intend to pull the plugs at 20K miles just to examine them. But this is the 4th vehicle I have had them in.

Changing them the second time will be a piece of cake...1.5 hours.

Autolite#..AP3924

So does your foz doesn't run rough with the autolite plats? All the ppl at work (autozone) say I shouldn't put anything in with a different heat range. The foz is spec to 6 (NGK only basically), those are 3...

 

[FPT_RAIDER]

hey now, youcan get some good dealership techs............i my mind what it comes down to is flat rate. when you pay a person for 1 hr, but you can do that job in .5 hrs, then you can make twice as much in an hr, but at the same time just because you an do it in a .5 hr doesnt mean its done the right way sadly, this coming from some who is going to school to became a tech and sadly i had to sit through 3 weeks of all that stuff, which is why i love diesel!!!!! hourly baby!!!!

 

[FPT_RAIDER]

So does your foz doesn't run rough with the autolite plats? All the ppl at work (autozone) say I shouldn't put anything in with a different heat range. The foz is spec to 6 (NGK only basically), those are 3...

it depends on how your engine is set up, if your engine is stock then yes, but if not then you may need to change the heat range. i havent had the power and performance class at school so i dont want to say moreb

 

[neoshi]

if you run too low of a heat range, do you risk oil leaking into the plug chamber?

 

[Real Lyte]

Yeah, simply I would be concerned in general dropping from heat range of 6 to 3, anyone have a definitive answer?:crazy:

 

[adc]

I really was not aware of that. Not doubting you on this but where is that information?
If this is true, I'll have to pull them.

Additional Information: I called up Autolite Technical Service. They indicated that the NGK-FR-5AP-11 is a Heat Range "5". The Autolite AP-3924 is a Heat Range "4". The Last # is the Heat range. The next plug that Autolite makes is a AP 3926 which is a "6" heat range.

So based on that I will keep them in 10K and check them then.

 

[Real Lyte]

I really was not aware of that. Not doubting you on this but where is that information?
If this is true, I'll have to pull them.

Additional Information: I called up Autolite Technical Service. They indicated that the NGK-FR-5AP-11 is a Heat Range "5". The Autolite AP-3924 is a Heat Range "4". The Last # is the Heat range. The next plug that Autolite makes is a AP 3926 which is a "6" heat range.

So based on that I will keep them in 10K and check them then.

I will have to search for a concrete source to this accusation by the guys at work...but they all say that your car will run like crap and sometimes causes other problems because of unburnt fuel etc.

 

[adc]

I will have to search for a concrete source to this accusation by the guys at work...but they all say that your car will run like crap and sometimes causes other problems because of unburnt fuel etc.

I will be doing my daughter's 08 this weekend. Might go to Subaru with Subaru Bucks and get plugs from them.

 

[Real Lyte]

I will be doing my daughter's 08 this weekend. Might go to Subaru with Subaru Bucks and get plugs from them.

Sorry I haven't researched it much more because life has been busy, if I get some time tomorrow I'll pick my father in law's brain (manager at autozone and vintage car lover). :biggrin:

 

[dubaya1]

Bosch plugs

I went to my local O'reilly Auto Parts store and asked for an equivalent plug to the OE. They sold me Bosh FR8DPX, which I think to be a hotter plug then recomended. At first it seemed that my car was gasping for air when I accelerated (which is weird because I am also running a K&N air filter and try to use 89 octane gas). Recently, to compensate, I ended up taking off the very first section of the "breather box"(?) (The front half of the air intake part that is removed to access the the passenger side pulgs.) It runs smooth now except for initial take off (from park) seems to be a big lag with a delayed "jump start" from setting still to moving. How does anyone feel about the effects of running hotter plugs in an 03 fx or any Foz for that matter? Note: Milage has always been with-in EPA estamated milage.