Backed out / blown plug

[Svashtar]

Hi guys, been awhile. Shows how much I have left to learn about our cars, I had no idea that Ford 4.6 and 5.4L engines were known for this. I’ve had 32 different spark plugs installed in my car (2003, 128k) all torqued to 20 ft lbs, all with a tiny bit of anti seize on the threads, and no issue until yesterday. Car started slightly missing, I could feel it vibrate at idle. Got worse over the next 30 minutes, so I started home to put it on a reader when the engine light came on in my driveway. Code indicated bad plug on cylinder 7.

Pulled it and plug came with the coil over plug. It’s a long thread NGK that Marty O recommended. The plug was pristine, so it backed out slowly. Before doing anything else I checked the other seven cylinders, no movement on tightening to 20 ft lbs., but took them all to 22 just in case.

New plug won’t thread in. I’m picking up a thread chaser today, see if I can get lucky, but I’m not hopeful.

Search here shows a “timesert” kit is recommended, but it comes with 5 inserts and I only need one. If the thread chaser won’t work is this still my best option?

It looks like the plug slowly backed out, but must have damaged at least the top two threads when it finally popped out under compression. (Now I’m reading online that 100-200 miles after spark plug change you’re supposed to reinspect and retorque. Somehow missed that key info!)

Finally, the bottom rubber of the coilover is slightly damaged. Not bad, about 1/4” of missing rubber on one side. I replaced the coilovers with Granatelli solid coil connectors years ago, so have the original coil over covers and will replace it with one of those, hopefully they are the same even though the coil connectors are different.

Ok, please let me know if the timesert is still the way to go if trying to clean up the existing threads doesn’t work, thanks.

 

[Svashtar]

Ok, spoke to a guy at Marty’s speed shop in Georgia, then went to NAPA and asked them for a head thread kit; they sold me something called Plug-Saver, p/n 98141, “Fix-A-Thred”, made by Howmet Aerospace. Kit contains a tap M14-1.25 that looks like it starts at 14mm, then expands to cut new threads. Then a set of three inserts, a short, medium and long, then a simple drift that you evidently use to expand the throat of the insert (after coating the outside of it with a high temp RTV silicone) to make it a permanent install that won’t back out in the future on its own or with the plug. No mention of any pre drilling, this is evidently self tapping.

Says to use insert that matches your plug, so I’ll use the longest because the NGK plug threads are easily twice as long as the OEM Motorcraft or cooler Motorcraft plugs.

Looks pretty straightforward, my main concern is using heavy grease on the tap threads to keep aluminum chips out of the cylinder. I’ll post here later in case anyone’s interested.

 

[Svashtar]

By the way, I just checked and my plugs have always been torqued to 11 ft lbs as per Reinhart back in the day. That’s probably the problem. Googling now everyone recommends 20-22 in these engines, with little or no anti seize.

 

[BackNBlack]

...my plugs have always been torqued to 11 ft lbs as per Reinhart back in the day.

Sorry to hear he ever TOUCHED your MARAUDER...

Is he Dead Yet??!!

 

[Svashtar]

He didn’t touch it. I never said he did. He provided Denso IT-20’s and along with them a sheet from Ford listing the published factory spark plug torque specs of 11-13 ft lbs. Those specs have since been updated over the years to 20-22, given the shorter threading on some Ford cylinder heads.

But rather than going to cooler Motorcraft plugs I’m sticking with the much longer thread of these NGK 4177 (TR6) plugs that Marty O recommends with his tune. In fact, since these have only 15k on them, I’m going to reuse the backed out plug as it still looks great.

 

[BackNBlack]

He didn’t touch it. I never said he did. He provided Denso IT-20’s and along with them a sheet from Ford listing the published factory spark plug torque specs of 11-13 ft lbs. Those specs have since been updated over the years to 20-22, given the shorter threading on some Ford cylinder heads.

But rather than going to cooler Motorcraft plugs I’m sticking with the much longer thread of these NGK 4177 (TR6) plugs that Marty O recommends with his tune. In fact, since these have only 15k on them, I’m going to reuse the backed out plug as it still looks great.

Got it…glad to hear. You’re MUCH better off with the NGKs. BTW…nice list of Mods…and good to still “see” you around. This coming June will be 24 years for me…I remember your screen name from back in the earlier days.

 

[Svashtar]

Got it…glad to hear. You’re MUCH better off with the NGKs. BTW…nice list of Mods…and good to still “see” you around. This coming June will be 24 years for me…I remember your screen name from back in the earlier days.

I remember you as well! You’ve been here a year or so longer than me. Hell, you must have signed on near your cars born on date! This July will be 22 years since I bought my “new” 2003 300B which had been sitting for 21 months at the dealer, with 300 miles on it from the sales manager driving it around, and signed on to this list when you and Logan were here.

Until this it ran like a champ, with some work of course, my biggest issue is the paint, it’s just destroyed. Between the lousy factory black and clear coat, and I made the mistake of hiring a local “expert” to wash the car, and he used hard water in the hot sun then a powerful buffer to buff out the spots, and literally burned off paint and pieces of the trim snd spoiler. . Total hack, and on me for being lazy, so the plan is to get a repaint this year. And yeah, DR sold me all sorts of junk including a lousy overpriced mustang tune, thank God for Marty! (I actually think my original SC 1725 canned tune was better than the DR tune!) But we all didn’t know any better. Wes at Innovative was a great guy as well.

There was one other forum guy who I think took advantage and was a bit of a jerk, but I won’t go there.

I did his DR rear engine cooling mod and my mechanic improved it a bit by angling some of the fittings when the tranny was out for the Art Carr rebuild, and I changed my tee connections in the engine bay to metal ones, which was an absolute beyotch of a job, but I dread when that will eventually fail. I understand that someone came up with a better less involved one years later. (?) The car will probably be my sons when that happens!

Unfortunately my mechanic who had worked directly as a Ford service manager for 20 years before opening his own shop died unexpectedly last year, only 2 years older than me, and finding a good replacement hasn’t happened.

Good to hear from you.