Spark Plug Mystery

[Alec]

Before I begin: note: no maintenance or work has ever been performed on my truck without my knowledge and/or consent. I am the original owner.

Anyway, Splat has almost 60k miles and even though the maintenance book says to change the plugs every 100k I figured I'd get mine changed and go a heat range cooler for the s/c and n2o. All 6 OE plugs were pretty much shot, though after careful examination, just due to normal wear, and not fuel conditions or undue stress (except for 1 that was replaced 2 weeks ago from an accidental 200 hp shot ). It was just time for them to be changed.

Here's the weird part: the left side of the motor had double platinum motorcraft plugs, while the right side had single plat's. ??? The plugs hadn't been touched since the truck left the factory. I dunno what's up with that.

Anyway, we replaced all 6 with double plat motorcraft plugs, 1 heat range cooler than stock. The truck runs great now, it's much smoother and a bit quieter. I even advanced the timing a bit (via the s/c computer) to take advantage of the new plugs. All in all, I'm very pleased. I've yet to run the n20 with the new plugs, but I'm sure it'll be better than before.

NOTE TO ALL X OWNERS: Do not follow the factory guidelines and replace your factory plugs at 60k, not 100k. Plug wires, too. My plug wires were replaced 18k miles ago with the s/c install. 8mm motorcraft heavy duty wires are fine.

Thanks for reading!

 

[mrboyle]

I agree with you on the 60K plug change. When my parents got their '96 it had 69K on it and got really
sh!tty gas mileage. After changing the air filter (put in a K&N), fuel filter and putting a Flowmaster on it the mileage had only increased 2-3mpg. Did a tune up to it and got another 5mpg out of it.

As for the plugs, I have seen that before, but never on a Ford (Chevy loves to do it)

 

[B94Sport]

I had heard about that difference in spark plugs on the explorers... There must be a reason for it. Incidently, I recently had to replace 3 of my 6 spark plugs - and yes, they were all on one side of the engine; the driver's side. For some reason those plugs were really fouled up, so much so that the engine shook violently when idling. They were Bosch Platinum +4s, which I have since been told are crap (and now believe it). They only had about 25,000 miles on them. I can't imagine one side of the engine operating under different conditions than the other, but there must be some logic behind Ford placing one type of plug on one side of the engine and a different type on the other side... Hmm...

 

[procyon]

Read up more about the different spark plugs in this thread. You would be surprised what has already been discussed before and can be found with the search button.

Dead Link Removed

 

[Alec]

Cool, I'd forgotten about that thread. Ya, both mine and my mechanic's service materials only listed the double plat as service plugs. I still think it's kinda silly though.

 

[DocVijay]

Other manufacturers do it too.

Our Toyota Avalon has two different sets of plugs, one for each side of the V. The manual even has two different part numbers. I asked the service guy and he just told me to replace them all the same. I put in Bosch +4 Platinums and haven't had any problems. I'm sure there's a reason, but it escapes me.

 

[allens1564]

Want or need to replace #AWSF-42PP spark plugs on my 1994 Explorer XLT 2wd.
1994 Explorer has jittery engine after cold start. Need to "weed out" possible problems.
I have read different explorer-forums and ford-truck postings on using recommended Motorcraft or Autolite Double Platinum. The closest I could find online - Amazon, Advance, O'Reilly, were Autolite Double Platinum APP605. Is there a better spark plug for a stock engine.
Also could you recommend a brand/model for spark plug wire set and distributor cap. Appreciate any advice/experience. Thanks.

 

[allens1564]

Want or need to replace #AWSF-42PP spark plugs on my 1994 Explorer XLT 2wd.
1994 Explorer has jittery engine after cold start. Need to "weed out" possible problems.
I have read different explorer-forums and ford-truck postings on using recommended Motorcraft or Autolite Double Platinum. The closest I could find online - Amazon, Advance, O'Reilly, were Autolite Double Platinum APP605. Is there a better spark plug for a stock engine.
Also could you recommend a brand/model for spark plug wire set and distributor cap. Appreciate any advice/experience.
Thanks.