I took my car to the dealer earlier this week because the car was idling alittle rough. They found the #7 coil to be bad and they replaced the #6,7 spark plugs. How do 2 of 8 plugs fail quicker than the rest? I only have about 75 miles left on my warranty so any future repairs will be done by me, i am thinking about replacing the other 6 plugs. Does anyone see a purpose to this? It doesnt look like the coils and plugs are too hard to get to, few screws to the plastic cover, few screws for each coil. I think i just wanna replaced everything with new parts. Right now my engine is like a frankenstien of mismatched parts, 4 new coils, 4 old coils....2 new plugs, 6 old plugs.
Dealer visit/spark plugs ?
- Thread starter Fla02LS
- Start date
02LSE96LSC91SE84TC
Dedicated LVC Member
I can't believe a dealer would only replace 2 plugs. Bad enough just a few coils at a time when they know the others will fail shortly after.
Jim Henderson
Dedicated LVC Member
seems like if things are under warranty the dealers are told to replace only the defective parts. When it is your money they remove and replace whole assemblies.
My dealer also replaced one coil at a time during a recent warranty service. The problem kept jumping to a different plug/coil so they kept playing with it for a couple weeks.
Finally the factory rep had them check the plugs which turned out to be NGK. The rep said "Not OEM plugs, no warranty". Turns out later that yes NGK is ford factory installed so the warranty was back on. Seems like the factory is awful quick on the draw to deny warranty claims, hmmm.
They finally replaced 8 plugs and coils. Why it took 2+ weeks is a pain and probably like I said, the factory only authorizes specific replacements, one at a time.
I bet if the car was not under warranty it would have been all 8 plugs and coils from the start and a big chunk out of my wallet.
By the way coils are something like $120 each so you want to get as many replaced under warranty as you can.
Good Luck,
Jim Henderson
My dealer also replaced one coil at a time during a recent warranty service. The problem kept jumping to a different plug/coil so they kept playing with it for a couple weeks.
Finally the factory rep had them check the plugs which turned out to be NGK. The rep said "Not OEM plugs, no warranty". Turns out later that yes NGK is ford factory installed so the warranty was back on. Seems like the factory is awful quick on the draw to deny warranty claims, hmmm.
They finally replaced 8 plugs and coils. Why it took 2+ weeks is a pain and probably like I said, the factory only authorizes specific replacements, one at a time.
I bet if the car was not under warranty it would have been all 8 plugs and coils from the start and a big chunk out of my wallet.
By the way coils are something like $120 each so you want to get as many replaced under warranty as you can.
Good Luck,
Jim Henderson
The invoice i just got yesterday listed the coil assembly (2W4Z 12029 BD) having a cost of $33.32. It seems we can replace all 8 for around $250 now.
Yeah I have... well, changed plugs; not coils. But to do the plugs, you have to take out the coils so essentially, same thing. Anyway!!! Biggest things to do are blowout the plug wells with compressed air before you remove the plug; this way no debris will get into your combustion chamber/cylinder. Second, put a light coat of anti-seize on the threads of the spark plug. THIS IS ESSENTIAL!!! Don't forget to do this or the dissimilar metals will corrode and then next time a plug needs to be pulled, your aluminum threads from the head might be coming with it! Reinstall plugs, install the coils (don't forget some dielectric grease in the boot; it ensures a good electrical connection and prevents moisture intrusion). Button it back up and you're set. It shouldn't take more than 1-2 hours, even with having to work around the brake booster on the left (driver's) side.
Why you would ever only change some of the plugs is beyond me. It is very uncommon that they will wear at different rates; if they do, you've got a whole lot more problems than the extra 6 plugs you're replacing. It means mechanically you have problems in your engine that's causing those particular cylinders to either burn hotter, or allow carbon to build up on the plug. Either way; you should NEVER have to replace only SOME plugs.
Anyway, anymore questions just ask. It really is an easy job... just have a good set of wrenches and a little patience on the back two bolts on the left side. Good Luck!
PS, don't forget to gap your plugs before you install them!!!!
Why you would ever only change some of the plugs is beyond me. It is very uncommon that they will wear at different rates; if they do, you've got a whole lot more problems than the extra 6 plugs you're replacing. It means mechanically you have problems in your engine that's causing those particular cylinders to either burn hotter, or allow carbon to build up on the plug. Either way; you should NEVER have to replace only SOME plugs.
Anyway, anymore questions just ask. It really is an easy job... just have a good set of wrenches and a little patience on the back two bolts on the left side. Good Luck!
PS, don't forget to gap your plugs before you install them!!!!
oh also... Generally on coils, you can actually check for the bad one if you get specs on the resistance readings you should get. I don't know if FMC has specs on the coils for what is good and what is bad or not. But by and large it's generally not something a good mechanic would just use the diagnostics and call it a day. Generally you verify the problem through actual testing. Do all coils need to be replaced at the same time? No, they really don't. Is that saying they won't failing on you later down the road? No, but it also isn't saying they WILL fail. Of course, as we know...coils seem to be a weakness in these engines so it might be safe to reason that once a couple of them go, watch for a couple more to follow. But it isn't set in stone either. My advise; if you can afford it and you're already in there, go ahead and replace the rest of the coils. However, if you can't afford it, then don't worry about it. You could have another 1000 miles, or 50,000 miles before you have another coil problem so don't sweat it until it happens. Choice is yours to make though.
Jim Henderson
Dedicated LVC Member
That is good to hear. Last I read on this site was they were a lot more expensive and some guys were looking for alternate sources because of this. I hope they redesigned them since so many of us are having problems with this.
My one time experience and opinion is that these coils are heat sensitive and or there is not enough airflow to cool them.
The reasons I say this are
1) Most COPs I have seen are out in the open where they can dissipate the heat they may generate and probably more importantly, avoid the heat off the cylinder heads. Ours are buried down in the valve cover and have a plastic trim cover to close them off.
2) My problems with coils started on a hot(105+) August day last year when there was a huge wreck on the freeway and it was shut down for about 90 minutes and there was no way to get off the freeway. So for 90 minutes I sat in my car with engine running and full blast AC, no way was I going to stand out in the sun with 105+ temps(yes I know, sissy) and sure wasn't going to sit in the sauna. Everything seemed fine and the engine was running smoothly. The temp guage read just a little above the normal spot it runs at but nothing to worry about so I think.
As soon as the freeway opened back up I accelerated away but the car was missing badly and the check engine light started flashing. It got a little better as things cooled down, it ran better but had a definite stumble and the check engine light would flash periodically. The dealer replaced 3 coils at that time.
My guess is like I said, the coils overheated because they are down inside the valve cover where they get baked by the heat coming off the cylinder head and there is NO airflow too cool them. I am almost tempted to kludge something up to force cooling air inside the coil valley.
Just my opinions, and glad to see we can get coils cheaper than I thought. I bet we are all going to need them again.
Jim Henderson
Not to try to throw a wrench in the works, but i don't think the news is as good as it sounds. If it was covered under insurance, that coil will only be charged as the wholesale cost. Whatever the dealership pays for it. So just keep that in mind...
Well, usually plugs are a mileage issue. Only other reason would be rich/lean condition over a prolonged period of time. Or internal engine problems.
"Kill any cats?!! j/k. That was too funny..."
Nope. Honestly, after i had that whole blowup about the cats i havent even seen them. I was actually in the store ready to buy a gallon of antifreeze but didnt do it. Partly because antifreeze isnt as cheap as i thought it was and i had a change of mind. I guess a higher power told those cats they needed to find a new home.
I am at a loss as why only two plugs needed replacing. The reasons given so far kinda make sense, the #7 coil failed which i suppose could ruin the #7 plug, but why the #6 plug went bad is beyond me. Here is what they tested from the invoice:
Road test. EEC test, pass. DCL and Idle Data Display. PWR Bal test. Fuel Pressure and Leakdown Test. Inj Flow Test. Monitor & Record. Perform Ign Test. Replace #7 coil and #6 and 7 plugs. Retest and Post Road Test. Ok
Total Charge: $297.03
Nope. Honestly, after i had that whole blowup about the cats i havent even seen them. I was actually in the store ready to buy a gallon of antifreeze but didnt do it. Partly because antifreeze isnt as cheap as i thought it was and i had a change of mind. I guess a higher power told those cats they needed to find a new home.
I am at a loss as why only two plugs needed replacing. The reasons given so far kinda make sense, the #7 coil failed which i suppose could ruin the #7 plug, but why the #6 plug went bad is beyond me. Here is what they tested from the invoice:
Road test. EEC test, pass. DCL and Idle Data Display. PWR Bal test. Fuel Pressure and Leakdown Test. Inj Flow Test. Monitor & Record. Perform Ign Test. Replace #7 coil and #6 and 7 plugs. Retest and Post Road Test. Ok
Total Charge: $297.03
If the misfire lasted long enough, I could see replacing #7 plug. But as you said, shouldn't be any reason to replace #6.
Unless the #6 coil is about to go.