I need some help on finding the best place to get ignition coils for my 03 STR. My understanding is that OEM coils are best, but am curious if there are any alternatives because $900 is steep for all OEM's. So far, this is what I have found via the search function and googl and the BWD's look to be good enough relative to OEM's:

OEM $108: Jaguar IGNITION COIL, COIL-ON-PLUG TYPE. - AJ810445

BWD $78 until Dec 1: BWD/Intermotor Ignition Coil-E1019 - Advance Auto Parts

Various at Rockauto from $35 to $28, quality is suspect for the price.

http://www.gaudinjaguarparts.com/ OEM? is $77

 

I plan to change one at a time when any fails. Do you have faults?

 

I bought 4 SMP UF519 coils off e-Bay last January,paid $37 each--when they arrived they were genuine Jaguar coils in Jaguar factory packaging!The ad is still there,but I don't what coil you will get now.
I just keep them on the shelf for spares.

 

I bought all mine from Advance Auto. Use a coupon code to get a better discount. I always used code p20

 

No faults and no P30X, and after reading several of your posts last night, I am experiencing hesitation or a slight miss under load in 5th or 6th under 1800rpm when I hit the gas slightly hard. Under boost its fine, and at idle its perfect, so I am leaning toward the coil(s) being bad. I also just purchased an ELM327 off of amazon last night, so I will report back with ltft and stft mid next week. Also, the intake from the MAF back has been smoked, and there are no leaks.

I read somewhere there is a tool that can test coils? I haven't done much research on where to buy (ebay?).

I guess my thought process is, if one coil is bad, I should replace them all, because eventually another will go bad and its no fun driving a car that drives less than perfect. It's some serious $$$ to spend to replace them all, but I plan on keeping the car for another 2 years and want to have that piece of mind.

EDIT: car has 64K miles

 

How old are the plugs?

 

Since 2003, or I guess 2002 when the car was manufactured.

 

COP (Coil on plug) tester. Abonano swears by 'em and he knows what he's doing.

 

You can buy a COP tester as JagV8 said (I have one and it's cheap enough to get one anyway) but that will only tell you if the coil is working. What you really want is a coil stress tester which most Ford dealers have.

With the Lincoln LS Ford was replacing way too many good coils under warranty and came out with a recomendation for their dealers to get and use the COP stress tester. It's much too expensive for a home mechanic.

With 64K miles I would change the plugs and fuel filter first. Sounds like you have a very small amount of misfires.
.
.
.

 

Replace the plugs while you are at it.

I took a wait and see approach to replacing all of mine. I'd buy an extra coil pack and keep it until one failed, then I would replace it. It is pretty easy to tell when one fails, but if you want to replace them in one fell swoop then go for it. It takes ~5 mins to replace a coil, maybe a few more to get to the back ones.

 

One of the goals of a COP ignition is to keep firing the plugs at an acceptable level even when worn.

However, there comes a point where the coil cannot overcome a worn plug. Worn plugs also stress coils.

I'd be inclined to change plugs before coils. At 65K miles, they are overdue.

 

My fault, that's what I get for reading the posts on my iPhone. The plugs were changed at 55k and I used the proper NGKs as noted by a few forum members.

I appreciate all the feedback. Still toying with replacing all I them...

 

As JagV8 mentioned - I have used a COP tester with success to isolate an intermittent misfiring coil(s) - however, in your case - I would lean towards clubairth1 here as one (or more) of your coils could be intermittently misfiring under load/stress.

First things first - check the spark wells for any sign of oil or oil residue that is caked on the COP boot. Oil notoriously fries coils over time...

As far as which COP to use - I live by OEM but I would refuse to shell out $900 to replace all 8 especially at 65K miles. I would certainly dig further before shelling out the $$$ and yes, you can have an intermittent failing coil w/o the OBDII throwing a P030X code.

 

Ok you guys knocked some sense into me. I am going to order one coil, and order one of the following testers below - however I need help understanding which one is better. Does anyone have experience with either?

$96

$23

 

One way would be to get a good new coil and swap by guesswork if there's no good evidence. If problem recurs, swap with another. Repeat till you find it (or get fed up!).

At $100 I'd swap the lot but at $900 I would not. They're easy to change.

 

The COP tester is more relevant to your issue than the spark plug tester - and more $$$

 

I've got all the coils left over from my engine swap. Garraunteed to work just fine. I'll let some of them go for $50 each plus shipping. Let me know if I can help you save a couple of bucks.

Ciao - Jim

 

I too have an '03 and frankly I'm quite surprised you still have the original COPs in there. I've had to replace mine years ago. The new ones I bought looked slightly different than the original, but new ones only cost $55 for from the dealership. And since half the time they're not in stock when I call, it's a good idea to keep an extra one on hand for the future.

You can try swapping two coils and see if the misfire moves.

 

Well I don't know how long they are supposed to last but my 2005 STR at 96K miles has all the original coils and plugs.

Still runs fine but I do have a new set of plugs and will be interested to see how badly worn my factory plugs are when I replace them. I have no idea if there is any oil in the plug wells but think not since everything seems OK. I do stress test them daily!


For some reason it is much less common for the 2003 and up cars to replace them. Maybe they are just newer cars that have not got to that age yet?
.
.
.

 

Hmmm, .... I didn't know about the older coils being upgraded. But I went into my records and found that Jaguar had replaced all the coils back in '09.

So, the question is: are these the "Upgraded" coils or not?

If so, and they are a bit less expensive now, I'll still make some of mine available at a discount to anyone who might want to save a few bucks.

Good luck to us all!