Champion 7989 sparkplug failure.

[Explorer_PL]

Brief recap of events:

At around 99k miles I developed a miss, that got progressively worse, and at around 101k miles I replaced all 8. 7 came out ok, with screeching and noises. 1 broke in 3 pieces, and I had to drill and tap the head. Installed Champions 7989, and coated them with nickel anti-sieze.

Last month at around 132k miles, I pulled them all out and recoated them again (most of it was gone). All was good for about 3 weeks or so. Yesterday, I went to work and back just driving on 7 cylinders. Found # 4 cylinder not working. Swapped the plug and the coil to # 2, and #4 was ok now, # 2 was missing so I knew it has to be either coil or plug. I still had the original plugs in the garage, so i just screw in the old Motorcraft, and it's fine.

This morning while driving to work, ocasionaly it would miss just a little, so either the old Motorctaft is missing, or another Champion is on its last leg.

I decided to replace all 8 again, and will go with Motorcraft.

Can I use Motorcraft SP515 ?

Nor realy happy with Champions lasting only 32k miles.

 

[feetwet]

Seems like overkill to replace all 8 again.

I had one 7989 that had a hairline crack in the porcelain that caused a misfire, but that was in a brand new plug, not one that had been working for while.

You might want to swap just the coil to another cylinder

 

[Explorer_PL]

I swapped both plug and coil. It was still missing, now on #2. So I replaced the 7989 with the original Autolite HT1 that I still had in the garage with 99k miles on it. It got to about 95% good, just ocasional misfire uphill, so I knew the coil was OK, the plug was the issue.

Since I do about 80-100 miles a day, i could not wait, and last night I bought 8 Autolites HT1 at Autozone. Total $103 less 20 rebate. Ebay had same prices. This morning before work I replaced #1 and #2 plugs (took me 10 minutes, I am getting good at it ), and drove about 40 miles and absolutely no misfire. Will replace the rmaining 6 in the next few days. Did not coat it with anything, as I am planning to unscrew them every 20k miles anyway.

 

[Explorer_PL]

Update -

over the weekend I replaced the remaining 6 plugs with the Autolites. Drove about 200 miles so far and not a single miss, waaaaaaay much better than driving with Champions (sorry Champion). Before, any attempt to pass a vehicle on the highway, or going uphill would produce a bucking and miss, and eventualy CEL light. I gueass Champions are not made for Fords.

 

[feetwet]

The only time my Champions produced a misfire was when I had a hairline crack in the porcelain on one plug. Once I got a significant enough misfire to register an OBDII fault and determine which cylinder was missing... I replaced my cracked plug, since then, they have been great.

If that was the case with yours, perhaps Champion needs to work on their packaging/handling/testing to prevent cracked plugs from getting to consumers.

 

[Explorer_PL]

Not sure if I had any cracks, the one that was at fault had the porcelain part much darker. So far so good.