Does anyone have a source for a good quality, aftermarket ignition coil for the 4.2L engine? The Jaguar OEM is now the Ford 6R83-12A366-AA coil priced at $85.00 online. Maybe not terribly unreasonable, but other members have commented that the same coil fitted for a Honda is around $20.00. Beck/Arnley parts have performed well for me, and their version is about $50.00. Once you go lower in price, I believe the quality gets iffy. Bought a set of "Standard Motor" coils from Rock Auto when one of my original Densos went out. Big mistake, as, in spite of all the glowing quality guarantees on the Rock Auto site, one of the coils had a short right out of the box. Of course, since I had installed the set, they would not take them back. My second episode with Rock Auto, as I previously was burned by buying a supposed OEM A/C compressor for the car that turned out to be missing the clutch pad on the sliding disk and had a dry, squeaking pulley bearing. Refund for the part, but cost $300+ labor to swap out. Will limit my future purchases from them to sparkplugs and filters - nothing more complex.


One other factor that dragged out the diagnosis of the bad coil was the shop manual I am using. It is the 2003-2006 model year, A30465-A48684 engine version dated 11May2011. The bad coil series of DTC codes, the P035X series, was apparently listed to read as for the 4.0L engine: passenger-to-driverside, front-to-back as to cylinder designation, the 1-2-3-4, 5-6-7-8 order. The reading I got from the OBD was P0354, which listed the affected coil as being at cylinder 7 (old 4.0L number 4), as that was the new number of the passenger-side, rearmost one, per the numbering on the 4.2L: 1-3-5-7, 2-4-6-8. The person revising the manual apparently assumed the ECM on the 4.2L would signal the codes in the same order as for the 4.0L. Of course, as I eventually determined (!!!!) this was not the case. The P0354 code given was correctly reading from the number 4 cylinder, per the new numbering of the 4.2L - the second cylinder back on the driver's side - and that coil proved to be the shorted one. The P0300 series of codes for general misfires (and perhaps others) was similarly listed in the apparently incorrect, front-to-back order. Maybe some help, if you are trying to find a bad coil.

 

Bill,
I have a complete set of known good used coils that came off my A32XXX VIN car when I swapped engines. Are you interested?

 

Back to Scardini:


Please let me know particulars: how old/how many miles/OEM Denso or other/price, etc.


Thanks for your reply/help.

 

Hi Bill,

Sorry for the delay - had to pull one out of stores. They're 70K miles old. They were used between May '09 and Nov'13 (four and a half years), but 30 of the 70K miles were put on between 2012 and 2013. I do a lot of highway driving! They never gave me any trouble and only came out with the engine swap.

They're OEM FoMoCo The numbers I can read are:6R85-12A366-AA 099700-1120. Is $40 apiece, shipped, reasonable?

 

Have you tried S.N.G Barratt Group. Not sure for your 4.2, I have purchased a few coils from them on my 4.0 and found them to be reasonably priced. Rich

 

Here is the cylinder numbering scheme for Jaguar AJ-V8 engines according to MY and ISO designations.

 

They apparently list only the standard Jag/FoMoCo coil under the new Jag number - AJ810445 - for slightly more money than the Jag dealers online - $88 versus $85 - as far as I could find on their website.

 

Too bad my edition of the service manual did not follow the new 4.2L layout when it was updated from the 4.0L - would have saved me some time. The current manual, per my mechanic, follows the correct cylinder order: P0354 now refers to cylinder 4, as it should. Just a transitory text error, no doubt.

 

Just a final postscript. Found the OEM coil (labeled FoMoCo 6R83-12A366-AA, same as the one now sold by the dealer) at CarQuest/Advance Auto Parts for $50. Offered with an "as long as you own your car" warranty and a little more peace of mind.

 

I checked again for 4.2L coils this week and Both Beck-Arnley and CARQUEST/Advance Auto Parts are now offering a Chinese generic coil, not the Ford/Jaguar 6R83-12A366-AA OEM coil. Choices appear to be to take your chances with one of the many generics or order the OEM from either Jaguar or Ford for $85.00 (online and perhaps locally).

 

I've purchased two of these and the work great in my 03