Ford Modular Motors Spark Plugs

JWA · 08-26-2013, 04:51 AM

Have been noticing a few threads regarding Ford's Modular motors, typically installed beginning '97, still in production as of 2013 model year. It seems most believe spark plugs are good for 100K miles which simply is NOT true at all!

You'll find changing them at 50K gives better performance and MPG's plus the added benefit of inspecting the Coil-On-Plug (COP) units and insulating boots at the same time. Many, many driveability issues are directly related to misfires due COP>plug issues, most easily diagnosed and fixed with a visual inspection. (That doesn't mean a good code scanner shouldn't be a part of your tool box though.)

The issue of blown spark plugs tends to be related to improper installation at some point, whether from the factory or a heavy handed mechanic not following the recommended procedures. It should be noted Motor Craft or Autolite plugs have proven themselves over time to be the best brand and type for these motors. Overall most modular motors do NOT have horrible issues with blown plugs but since we're more likely to complain about a failure engines that last 270K miles or more without an issue rarely get mentioned---I have one of those!

Also while I cannot verify it just yet its rumored the plug threads of the above mentioned plugs are slightly different from other aftermarket brands, just enough to possibly be a contributing factor. The rumor suggests thread profile of the heads is more closely matched to Motor Craft & Autolite. Regardless if this is just a rumor or not the relative trouble-free experience when using the Motor Craft or Autolite brands over the longer terms should be food for thought when changing spark plugs.

I'm also of the thought plugs left for 100K miles have a much, much higher possibility of being difficult to remove. Carbon and other built up deposits on the threads after twice the real "life" of a plug simply has to affect the removal process. That there exists a lot of recommended in-place deposit removal its rare to need such a practice at the 50K interval.

If you're able to see plugs removed at both the 50K & 100K intervals you'd be shocked how little of the electrode remains at 100K. Its a bit shocking to be honest, at least to those perhaps new or relatively inexperienced with vehicle maintenance.

Plugs are cheap, changing them gets easier each time out so there's no good reason to delay changing plugs up to 100K miles. The downsides are just too great and too plentiful to ignore changing plugs before 100K. Sure it makes us all quite giddy thinking we can forego a maintenance step since its "factory recommended" but for me I'll do what I can to extend the life of my engine, enjoy better MPG's and performance for just a few hours work on a nice day outside.

Feel free to comment or offer your own anecdotes pro or con here---the discussion might benefit others.

Thanks for reading!

carringb · 08-26-2013, 11:21 AM

I first did my plugs at 115,000 miles. They were pretty worn. They were not hard to remove.

Next plugs I did at 200,000 trying to get back on schedule. Shortly before that I also added the Diablo Predator tuner. They were still good but not good enough to put everything back together without changing them. Next change was at 265,000. I could see the mileage drop like I had just before the first plug change, so I figured I'd pull them. They were done. I attribute it to running the Predator. One of the programming changes increases spark intensity by increasing dwell time, so it makes sense the spark plugs wore quicker. I swapped in Autolite Irridum plugs (recommended by the Ford dealer). I pulled a couple out a few weeks ago to check at 355,000 then they are still within gap spec! I suspect I can probably stretch these out until 400,000 and get back on a normal schedule again.

So far I have only needed one coil pack. I also had to replace a boot (found during my inspection) so I put a new coil on that one too and saved the take-out for my spare. I have never had trouble removing a plug at any of the changes, or during this last inspection.

antibo12 · 08-27-2013, 08:52 PM

Thank you for what I think is excellent advice. The Ford Service Manager in Vancouver Washington agrees with you and says he will change the plugs for $260, which seems like a lot, but I am leaning towards having him do it. With a "new" 65,000 mile 5.4 2-valve that has sat outside for 9 years, is there anything else the Ford Dealer should do, or at least inspect?

JWA · 08-28-2013, 03:21 AM

Glad you found it useful Antibo12!

If you mean sat outside as in never being garaged but still driven daily or frequently most everything should be in good order. All my vehicles here in the midwest sit outside in all kinds of weather but that alone doesn't cause excessive maintenance issues when it comes to plugs etc.

The $260 cost if plugs are included is actually a pretty good price from any for-hire shop. I'd ask about price for each boot if they're needed as it would be rare for one or more to not need replacing. I use an NAPA/Belden part # 702418 for about $5 each myself but double check so you don't get hit with too high a price unexpectedly.

If your van has been running well, no Check Engine Light lit up apart then from the plugs everything is probably in good order. Have them check the various hoses etc especially the 90* PCV hose connection at the back of the throttle body. Dorman #46017 is suitable, Ford wants to sell you the whole "assembly" that excludes the PCV itself. If you're somewhat handy changing this along with the PCV it's a DIY project, typically requiring nothing more than a strong hand.

Ask them specifically whether they'll use anti-seize and what torque setting they use. Yes on anti-seize and about 21 ft/lbs on the final torque. FWIW this is something that should be checked about 3K miles after new plug installation---they sometimes work themselves loose.

BTW I was once quoted " 'bout $400 if nothing goes wrong......" by another dealer---that's just one more reason I do this myself these days!

antibo12 · 08-30-2013, 10:33 PM

JWA, Thanks again. I think the van has probably sat for several months several times in its 16+ years. I purchased it on 28 August and drove it the 200 miles home, and it is what I expected; not very powerful. I have not driven a van since my 1971 Dodge with a 318, so some of my concerns may be lack of familiarity with an extended 1997 Ford Sportsmobile with the 5.4. The A/C is not very cool. The steering seems to require too much correction, and "too loose" may be correct. The brakes pull too much to the right, and I will have them checked, especially since the previous owner said he thinks the rotors were turned twice. The shocks at 65K are original, as are the plugs. The tires are 3-year-old 245 Goodyear Wrangler and they are quieter than I expected. The water connection was broken off outside years ago, and the previous (original) owners never used the water tank. I will want to fix that or have it fixed. The inside is in excellent shape. There is only one house battery, which I an going to try to uncover soon, since I hope to find room for a second battery for many reasons, including the fact that it has a 12v/110 fridge and not propane. Any additional advice you care to give me will be much appreciated.

JWA · 08-31-2013, 05:10 AM

Sent you a PM about some of your issues Antibo12, those not related to modular motor spark plugs.

I'm not familiar with the finished Sportsmobile, most specifically its weight but the E-Series vans bare stock weigh about 5,300# and they're a bit spunky, plenty of power. When they weigh closer to 7800# (as my daily driver work van) they're far less responsive accelerating and of course stopping distance is somewhat different. Mind you nothing horrible on either counts, just noticeable.

In fact I've driven my '00 E250 w/5.4 motor before, during and after being fitted as my work truck. Its quite different, the renewal of the suspension almost completely is very apparent.

Your van averages 5,000/year which might be another contributing factor to its lack of power as you experience.

Anyway read the PM and I'm hoping that too is helpful.

carringb · 08-31-2013, 07:58 AM

antibo12 - THe steering slop is typical for a worn out front end. Many of the bushings will dry out and crack even it if isn't driven. The pulling is likely a sticking caliper.

The good news is there is a good fix for both! In 2008 Ford made some big improvements to the front end including larger ball joints, replacing the donut bushings with hyme joints, and installing MUCH larger brakes. I swapped in an '09 axle from QuadVan and it made a huge improvement in driving, and now I don't have to replace bushing every 100k.

JWA · 08-31-2013, 09:14 AM

I'd hoped this would be a thread about modular motors spark plugs and their issues!

regis101 · 12-14-2018, 01:30 PM

Bouncing this one back from the days of old. I'm wondering if the blown spark plug issue is only for the 2004-2008 as stated in the link.

https://www.consumerreports.org/cro/...-tsb/index.htm

I might stand corrected. Couldn't find when this was written though.
https://repairpal.com/tsb-for-possib...nder-head-518#

boywonder · 12-14-2018, 01:46 PM

"The engines in question are three-valve V8s, mostly 4.6- and 5.4-liter powerplants, found in many Ford Explorers, Explorer Sport Tracs, Expeditions, and F-Series pickups, and Mustangs, Mercury Mountaineers, and Lincoln Navigators and Mark LTs."

Notice the "three-valve" V8s.......the E series got the two valve flavor of the modular engine, that's why the vans are not listed above. Although I think there was some spark plug removal related issues for some of the earlier post '92 vans.....