I am considering checking the plugs on my 04 WRX at the upcoming 30,000 mile service point. While it seems most folks are OK with leaving the OEM platinums in the car until 60,000, I wonder if they might have worn since installation. If the gaps are indeed off spec, is it wise to re-gap them ( taking precautions to avoid damaging the platinum center electrode) or is it better to simply purchase a set of new plugs? If the latter, would Subaru void warranty if Iridium's are used instead of platinums?

Your thoughts?

 

If the gap has opened up beyond factory spec, they can be carefully re-gapped. I would be surprised if that much wear had occurred with platinum (or iridium) spark plugs. Try to find a gapping tool that utilizes a notched blade that works without making contact with the center electrode, rather than those circular gapping/measuring tools that have a hole that is used to open up the gap.

In my opinion, using Iridium spark plugs would not cause an engine component failure that could be blamed on the plugs, thereby denying warranty service, but you could call around to various Subaru dealerships to get their opinions. The precious metals only extend service intervals but if you replace them on the recommended schedule, this follows factory procedure.

I use NGK Iridium plugs in my '02 WRX but replace them every couple of years or so, just because it is a minor expense to make sure all is well. I like to compare the plugs to make sure they all look similar (no oil fouling, excessive wear, etc.) and since I have them out, I might as well replace them with new ones. It's not absolutely necessary, though.

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0==WW==0
"…axles of evil…" - george w. bush

 

Thanks Wingless. I was pretty much headed in the same direction you have described. Will talk to my local Subaru dealer about the iridiums - just to be sure.
Not sure what gapping tool you are describing. Do you have a pic or link handy that shows the thing?


BTW. Nice mileage numbers. The best I have had is 27.8 mpg towing a small aluminum boat from Santa Cruz to Reading.


Rob

 

Try looking for something like this model I found at Sears.com. If the link doesn't work, just search Automotive Tools at Sears.com and several spark plug gap gauges will show in the results. Those notched 'keys' can usually open or close the plug gap by bending the side electrode. Better than tapping on a work bench.



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0==WW==0
"…axles of evil…" - george w. bush

 

Thanks Wingless. Another excuse to buy more tools........