Interpreting Spark Plug Wear 96 Explorer 4.0L OHV

[pmonahan]

30,000 miles on Platinum Motorcraft Plugs. See Photo.

I've had two opposing opinions on this, wondering what others think

Peter

 

[koda2000]

looks like the engine's running quite lean. the ceramic tip should be tan, not white. white indicates lean which means high cylinder temps.

 

[SoNic67]

It means wrong plugs. MC Platinum are not the OE spark plugs on your engine, probably they have wrong temperature range too - that's why they run hot.
Your engine requires as a minimum dual platinum plugs, because of the ignition type.

 

[pmonahan]

It means wrong plugs. MC Platinum are not the OE spark plugs on your engine, probably they have wrong temperature range too - that's why they run hot.
Your engine requires as a minimum dual platinum plugs, because of the ignition type.

I was told the Motorcraft Dual Platinum has been discontinued. Shop installed these.

Not trying to be snarky, but if the Dual Platinum is the *minimum*, what can be used that will exceed the Dual Platinum specs ?

Also, would you consider the plug to have "failed" based upon that photo, or about normal wear for 30,000 Miles considering it's running hot ?

Peter

 

[swshawaii]

http://www.rockauto.com/catalog/x,carcode,1119653,parttype,7212

Autolite XP605
http://www.rockauto.com/catalog/moreinfo.php?pk=904944&cc=1119653

 

[lobo411]

I was told the Motorcraft Dual Platinum has been discontinued. Shop installed these.

Not trying to be snarky, but if the Dual Platinum is the *minimum*, what can be used that will exceed the Dual Platinum specs ?

Also, would you consider the plug to have "failed" based upon that photo, or about normal wear for 30,000 Miles considering it's running hot ?

Peter

I've been using single platinum AP605s for 10+ years in my 1996 4.0 OHV and never had an ignition issue in all that time. Never had anything but normal deposits on the plugs, and I still get a good 20-21 MPG on a freeway commute after 155k mi.

 

[deweyville65]

I do believe after 2 1/2 years,the plugs in my 96 4.0 OHV are Autolite AP605. In that time I have replaced one plug because of failure of the plug. Runs good, starts as soon as cranked, fuel mileage around town averages 18 M PG since I replaced one of the O2 sensors. Was getting nearly 20 MPG before.

 

[SoNic67]

Not trying to be snarky, but if the Dual Platinum is the *minimum*, what can be used that will exceed the Dual Platinum specs ?

Fine tip platinum or iridium with platinum plated ground strap. Because the waste spark ignition system.

http://www.ngksparkplugs.com/products/spark_plugs/laser_platinum.asp
http://www.ngksparkplugs.com/products/spark_plugs/laser_iridium.asp

Simple fine tip platinum/iridium are good for Coil-On-Plug ignition.
Single platinum are good for ignition systems based on rotary distributor.

 

[pmonahan]

If the consensus is that the plug is too hot, should I be running a colder plug than the APP604 Autolite ?

Autolite says the next step down is the APP104 and I'm wondering if I should change to that plug.

Peter

 

[lobo411]

Fine tip platinum or iridium with platinum plated ground strap. Because the waste spark ignition system

Thanks for the link! It verifies what I originally thought, though: the only difference between single and dual platinum is that dual platinum electrodes don't wear as quickly. The pdf doesn't mention anything about higher/lower temps or better fuel economy or anything.

 

[pmonahan]

I spoke with Autolite today. I sent them the photo. One of their engineers indicated that:

1. The original spark plug spec by Ford calls for a single Platinum Plug for this motor
2. Double Platinum plugs will last longer
3. The plug in the photo is the correct heat range, but their intrpretation is a fuel issue. Could be local additives or some unknown fuel issue.

 

[swshawaii]

http://www.autolite.com/enmx/learn_more/technical_documents/tech_specs

 

[pmonahan]

This is a representation of the new Double Platinum APP605 plugs after one week of use. Something doesn't look right on the ground strap; they almost look "blued". The ceramic around the electrode looks "too white".

 

[Flash]

You won't find a better plug than NGK Iridium.

 

[rs2k]

You're looking for tan look the color of a cardboard box. The discoloration on the ground strap is normal and should start to occur half way between the tip and the base right along the curve. If the discoloration ends too close to the tip that indicates the plug you are using is too cold. Of the discoloration ends to close to the base then the plug is too hot for the engine.

To use this method effectively you have to shut the engine off in the load and rpm range you want to check. Letting the engine idle will only show you insulator color for idle. The plugs is here look like they are from an engine with a lean idle.