Misfire on highway,Spark plugs today

Hotrod Lincoln · August 17, 2017, 10:11:23 PM

The other day we were headed back from Vail at about 75mph and felt a shudder, or vibration. My CEL was flashing slowly, then 10 seconds later, it was gone. Running fine.

I ordered some SP534's and installed them today. Pretty easy install. Didn't have to unhook anything but I did crack the corner of a COP but just put it back on. All in took about 1-1.25 hours. Everything was very clean. The old ones were gapped 40-42 and one was at 45-46. New ones were set at 31.

Seems to run good. Hopefully that took care of the issue. The old ones were 528's. they didn't look horrible but definitely tired.

Macgyver · August 17, 2017, 10:30:27 PM

Ouch. Thats a big gap.

Hopefully that is the cause.

If it was winter. I would say some bad gas too.

Hotrod Lincoln · August 17, 2017, 10:33:48 PM

Quote from: Macgyver on August 17, 2017, 10:30:27 PM
Ouch. Thats a big gap.

Hopefully that is the cause.

If it was winter. I would say some bad gas too.

Yeah, I hope it's fixed. I only use 91 Costco gas. I was worried that I might have put 85 octane in it by accident but told the wife I don't think I would have overlooked that.

ZSHO · August 17, 2017, 11:05:53 PM

The platinum MC SP-528 look original based on the rust buildup on the porcelain. Z
I would of ordered some new COP for some reassurance.

NGK 58978
6 COP Boots Req'd; No Wires Req'd (Only 19 Remaining)
$3.71 ea

http://www.rockauto.com/en/catalog/lincoln,2011,mks,3.5l+v6+turbocharged,1446518,ignition,spark+plug+/+coil-on-plug+boot,10150

SHOdded · August 17, 2017, 11:57:58 PM

Good riddance to the 528s. They are prone to having issues anyway, as noted in Ford's TSB. Agreed on a new COP anyway, keep the old one as a backup/tester.

I guess no trouble getting the boots off? Plenty of stories about boots "welding" themselves to the plugs. PITA from experience

Hotrod Lincoln · August 18, 2017, 05:01:02 PM

Quote from: SHOdded on August 17, 2017, 11:57:58 PM
Good riddance to the 528s. They are prone to having issues anyway, as noted in Ford's TSB. Agreed on a new COP anyway, keep the old one as a backup/tester.

I guess no trouble getting the boots off? Plenty of stories about boots "welding" themselves to the plugs. PITA from experience

No. They looked perfect. The only one I had problems with was the one. It wasn't the boots either. It was just sealed really well. I already ordered a new COP per Z and you.

SHOdded · August 18, 2017, 06:24:45 PM

Rock it then sir!

Macgyver · August 18, 2017, 11:04:27 PM

Running Good now?

Hotrod Lincoln · August 19, 2017, 10:10:00 AM

Quote from: Macgyver on August 18, 2017, 11:04:27 PM
Running Good now?

Seems like it has better throttle response and I have yet to have it misfire again, although I haven't driven it more than a 15 minute highway ride yet. It does seem to have noticeable more power than it did. As wide as the gaps were it sure seems to me that was the problem.