Ignition Coil Cost/Quality

[il66pony]

Been having a jerking problem on my '07 4.6l Mountaineer - 76k miles. It intermittently jerks like it is mis-firing when accelerating form about 50 mph or maintaining speed on a hill. No codes thrown. Seems to be much more prevalent at ambient temps above 45 degrees Based on what I read here, I replaced the MAF. No change. I gave up and took it to the dealer.

Dealer could not replicate the jerking and said come back when it is doing it. Great. I wound up with a $79.95 car wash. Seems to be a pretty common problem from what I read online.

Anyway, I am thinking I should replace the plugs and coils. Coil prices seem to be all over the ballpark. On Rock auto, some are as cheap as $15-$20. Motorcrafts are $50. Is there a big difference in quality between the Motorcraft ones and the cheaper ones? When you are buying eight of them, it adds up!

Thanks

Dave

 

[Explorer_PL]

This is just my opinion, but I went that road many times over the past 11 years I have had my 06.
Motorcraft only, the others work for a while and you are back to the same problem soon enough. Find a good deal on Amazon or eBay for set of 8. You'll be good for a long time.

 

[il66pony]

Thanks, PL. So I looked on Ebay and found a set of 8 coils and 8 plugs for $112. Can these possibly be the real deal????

8 Ignition Coils DG511 & 8 Motorcraft Spark Plugs SP515/SP546 PZH14F For Ford | eBay

 

[MNgopher]

If you have access to an android phone and a cheap bluetooth OBD dongle, you should be able to isolate which cylinder is the actual issue. Using the Torque app, and going into the test results, you should be able to access the misfire data by cylinder. Usually you can find one or two cylinders acting up and start with the coils there if you don't want to change all 8 at one time. In my case, I've replaced two coils for similar problems on my '07, and eventually did over half of them on my '04 F150 with the 5.4 3V. It will take forever to actually throw a code... The test results will show it much earlier... (Surprised the dealer couldn't/wouldn't do the same with their info)

 

[Explorer_PL]

As MN said, you can do just the ones that misfire, and just work it from there.

That auction is for Motorcraft plugs and no-brand coils, nice try by the seller
None of the coils has the Ford part # on top of it.
I believe I paid about $ 300 for 8 OEM coils, that was the best deal I could find. That was few years ago and probably close to 80 k miles and they are still good.

 

[Bill MacLeod]

Dave
Why not replace just the plugs and see if that solves the issue. Also check for any moisture/corrosion in #4 and #8 plug wells. Use a dab on silicone grease on the coil boots.

 

[thebrakeman]

Agree. Plugs are a maintenance items. Coils are not, and should only need to be replaced when diagnosed bad (per coil, not all of them).

 

[rowekmr]

I just got a 07 Explorer Ltd that ran horrible (another story) that had codes for missing on 2 cylinders. I replaced coil on one, the other had coil disconnected so I replaced that coil and found out the plug was broken so changed that. Then I had codes on 2 other cylinders so after removing coils I saw the spark plug well full of sediment so blew that out and no more codes. Still had a slight miss with no codes so I had the other 7 plugs changed and NO MORE missing. Moral of my story is sometimes its the coils, sometimes there is debris or water in the spark plug well and sometimes its just the plugs. Everyone reputable says only use Motorcraft plugs some also say the Accel or MSD coils are decent too.

 

[Bill MacLeod]

Many on this site have experienced a slight stumble (or misfire) at around 50mph and on a slight incline with very light throttle pressure. New plugs often were the remedy for the issue.
Motorcraft are the plug of choice around here, although I have been running Autolite HT1 plugs the last couple of years. Champions did cause problems for me.
As brakeman said, "plugs are a maintenance item". They don't last near as long as the owners manual indicates.

 

[MNgopher]

I've had little to no trouble with the plugs failing on this type of ignition setup - assuming they are changed by 100,000 miles. Others report they fail earlier, but that has not been my personal experience with my current explorer, my previous F150 with the 5.4 3V, or fleet vehicles with the 5.4 3V (same ignition setup and plug type). Heck, my previous F150 had a full spark plug change and still had a stumble at 85k. 2 coils later... all was good. Plugs didn't look bad for the mileage. Not new, but not terrible either.

Inevitably, if one cylinder is misfiring, a coil change has usually done the trick -assuming the plugs have been done before 100k. Others go with 60k. Your choice I guess.

For both plugs and coils, I prefer to stick with the Motorcraft. We tried using other coils in my previous fleet - only to have way to many of those go south way to quickly...

 

[rowekmr]

Some have said Denso are the original manufacturer are the coils. Is that true?

 

[07EddyB]

100K on the plugs is definitely pushing it. I replaced mine at 79K and wondered how it was even running. I would show you a picture but we can't post pictures here.