Spark plug replacement outside of every 4yrs

[SV_WDC]

Looking for some advice please. My Gen 2 987 is going in for a minor service this week, with the service book stating that the spark plugs would not need replacing for another 2yrs.

Before purchasing the car I came across some threads with owners suggesting they like to get things like oil changes done more regularly than the maintenance schedule indicates.

Are there any benefits for getting spark plugs replaced early? Not something I'd usually entertain... but as it's going for the service I though't I'd ask the PH community

[Rockster]

SV_WDC said:

Looking for some advice please. My Gen 2 987 is going in for a minor service this week, with the service book stating that the spark plugs would not need replacing for another 2yrs.

Before purchasing the car I came across some threads with owners suggesting they like to get things like oil changes done more regularly than the maintenance schedule indicates.

Are there any benefits for getting spark plugs replaced early? Not something I'd usually entertain... but as it's going for the service I though't I'd ask the PH community

Spark plugs can be required to be changed on elapsed time as well as miles. My advice is to if you do not drive enough miles to require the plugs be changed and they become due to be changed based on elapsed time change them on time.

However, if the elapsed time is not yet to the point the plugs are due to be changed it is up to you whether or not you want to change the plugs early.

There is a slight benefit from fresh plugs but even with plugs with 60K miles on them (Boxster) or (IIRC) 48K miles (Turbo) I've never experienced any improvement from my Boxster or Turbo engine with a plug change. My driving is pretty consistent and I monitor fuel economy and I've never seen any real change in fuel economy from new plugs or even new coils and plugs (in the Turbo).

(Just so it is clear the above is not a recommendation to forgo scheduled plug changes!)

What I did see, well, experience, and this with my 2003 Turbo is after new coils (they had approx. 140K miles on them) and new plugs (which were done more of while we are there rather than because of time or miles (they had about 10K miles left before there were due to be changed on miles) were installed the Turbo engine ran noticeably better afterwards.

So much so that come the next Boxster plug service I'm toying with the idea of having the coils replaced (they are original and currently have over 310K miles on them) along with the plugs to see if the Boxster engine manifests any noticeable improvement with new coils. As I said above plugs alone has not resulted in any noticeable improvement from the engine.

I am an advocate of regular and probably more frequent oil/filter services. For instance my 2002 Boxster oil services were supposed to be every 15K miles with filter services every 30K miles. After just a couple of months of ownership (starting Jan. 2002) at 4K miles after an oil analysis that found considerable water in the oil (7%) -- subsequent data logging found the engine was very cold blooded in cold weather) I elected to change the oil then and there (well, as soon as I could drive the couple of miles home to the garage) and then every 5K miles thereafter. As mentioned above the Boxster engine now has over 310K miles and still runs great. Likewise my 2003 Turbo gets 5K mile oil/filter services and with "just" 155K miles runs as good as it did at 10K miles which is the mileage it had when I bought it used back in June 2009.

[ooid]

Rockster said:

What I did see, well, experience, and this with my 2003 Turbo is after new coils (they had approx. 140K miles on them) and new plugs (which were done more of while we are there rather than because of time or miles (they had about 10K miles left before there were due to be changed on miles) were installed the Turbo engine ran noticeably better afterwards.

impressive miles rockster, how is your driving routine? is it mainly open-roads and motorways I guess?

[Patrick Bateman]

If they're 2 years old I wouldn't touch them. Likely a waste of money.

[SV_WDC]

Thanks for the advice & some impressive mileage coming from that Boxster.

[Rockster]

ooid said:

impressive miles rockster, how is your driving routine? is it mainly open-roads and motorways I guess?

Quite a bit of my driving is highway/freeway. From Jan. 2002 when I bought the new Boxster up until July 2012 I would take 4K miles -- or more, one was around 8K miles -- road trips several times a year.

Might mention when I didn't drive the Boxster -- mostly due to the time of year -- I had a 2002 VW Golf TDi (I added this to my garage March 2002) that I drove instead. Sold this in early 2007 (with 140K miles on it so the VW got driven too) and bought a new 2006 Pontiac GTO (Holden) and put 40K miles on that car then traded it in April 2009 for a new 2008 Cayman S. After a short 4 weeks with a new 2008 Cayman S it was destroyed in an accident -- not my fault -- the day before my first extended road trip with the car was scheduled to begin. After the dust settled from the Cayman accident a few months later a 2003 Turbo came into my possession and I've had the Turbo paired with the Boxster now since June 2009.

Since July 2012 due to family issues -- caring for my elderly parents -- the road trips stopped and my driving was limited to my 60 mile work commute mostly highway/freeway with some around town errands tossed in as I drove my parents to their doctor appointments. (For this I used the Turbo as neither found it easy to get into/out of the Boxster. Getting in and out of the Turbo was hard enough. (And later the Turbo could carry a folding wheel chair behind the front seat backs.) Oh, I almost forgot, there was the nearly 12 months (from Jan 2012 to Jan 2013) another family member was confined to a hospital and I drove around 80 miles to see her several times a week every week she was in the hospital.

Even though my parents have been gone now since Nov. 2014 I have not resumed my road trips. After a 6 month layoff (Sept 2014 to Mar. 2015) I was rehired and have been so busy at work I have not had a chance to take any real time off. So there is my 60 mile per day work commute and a bit of errand running -- the Boxster is my around town car -- usually early Saturday morning. For my commute the Boxster gets the call 3 days a week, the Turbo 2 days a week.

Even with the big miles and all the time I've spent behind the wheel the Boxster is still a fun to drive car. I am amazed at how well the Boxster runs. It feels as if it has not suffered any decline in performance.

Oil consumption has gone up a "tick" maybe but still less than 2 quarts of oil in 5K miles. Might add I don't baby the car or the engine. While I don't go crazy around town or on the highway I run the car up through the gears whenever the opportunity presents itself. The engine doesn't get taken to red line (7200 IIRC) that often but still sees ~6K RPMs once everything's up to temperature.

I'm kind of looking forward to its next spark plug change to at the same time change the coils just to see if new coils makes a difference compared to the original coils with 310K+ miles.

[ATM]

How does someone go about analysing their oil?

[Rockster]

ATM said:

How does someone go about analysing their oil?

Maybe The Oil Lab?

http://www.theoillab.co.uk/

Here in the USA there are big rig truck stops, the ones that offer some servicing of big rigs, that have an on-site oil analysis machine. This is how I had the oil analyzed in my Boxster shortly after I bought the car. (Had put about 4K miles on it.)

The tech siphoned a bit of oil out through -- believe it or not -- the dipstick tube -- for some reason he was unable to "strike oil" trying to go through the oil filler tube -- into a small plastic collection bottle and then fed the collection bottle into the machine and closed the door and pushed the start button. A few minutes we had the analysis printout. Think I paid less than $20 for this.

Still in the USA there are companies, well, at least one I know of (2nd hand, I've never used its services) that you can send a sample too. Blackstone I think is the name. Not sure how one gets a sample bottle but the web site ought to covert this along with how to collect the sample and ship it.

For collecting the oil sample the big rig places take the oil sample from the filter housing but this will result in the oil testing a bit worse than it is.

I was always taught to start the oil draining from the oil sump/tank drain hole then wait a bit then capture some oil from in the middle of the drain. Kind of like the instructions for providing a urine sample. Not at the start, not at the end, but from in the middle.