I know with certain vehicles that some are sensitive to using only factory parts,while some operate just fine with aftermarket parts. So the question is,what brand(s) of coils seem to work the best for the X300? If possible please list price and purchase location. Thanks All.

 

The OEM coils are best and (despite the Lucas label) are made by Diamond Manufacturing in Japan. SNG Barratt has them

Lots of others, even with Lucas markings, claim to be OEM but they not and often give problems

Cheers
DD

 

More info here.....if you have time to read it all

https://www.jaguarforums.com/forum/x...0-coils-93966/

Cheers
DD

 

The parts vendor that got the Japan company to produce them again in on this forum. His handle is Japthug. Buy them from him. I did and got great service and good price.

 

Japthug posted that he was no longer offering them.

Cheers
DD

 

The "coils" thread above sums up in 229 posts: that the ONLY coils that work best for the X300 are the original Lucas (Diamonds). You would do better to replace bad coils with original used coils, than to purchase ANY new aftermarket coils. Most all of them are junk and will fail within a year.

 

Well,the idea of replacing coils with used original Lucas coils has crossed my mind too. I guess you can test them with an Ohm meter to see if they read OK but part of the failure of a coil is when they start arcing and there's no way to tell without actually mounting the coil in place and running them. It would be nice if you'd be able to try a used coil before purchase but your still taking a 50/50 chance that the used coil may be good. A meter can't test for arcing.

 

And testing primary resistance isn't conclusive anyway

The spec is .75 ohm, btw

I've had out-of-spec coils work perfectly well and in-spec coils malfunction!

And lack of arcing doesn't prove a coil is good

Seems like substitution is the only reliable method



Cheers
DD

 

Like you said,substitution is the only method,but there's no real way to tell if you've got a good coil until it's been installed and running. Those Ebay coils you listed cost approx $100 each. Now I know buying parts for longevity and reliability would be great (assuming you can get them),but what about some of the other coils selling on Ebay. I've seen some selling for $50 (6pk). I'm sure they're not as reliable and may not last as long but you'd also have 12 compared to the one. And changing a coil takes just a few minutes and just requires a small ratchet,torx bit and 8mm socket,easily stored as a tool kit with plenty of spare coils if they'd need replacing.Is there that much of a failure rate for cheaper coils? And approximately what kind of time periods are we talking about?

 

As I recall someone used Lincoln coils and had good luck. Had to rig the mounting system quite a bit.

Does anyone know where that was posted?

 

I had several non-OEM coils fail within 6-18 months, roughly.

Cheers
DD

 

I've been reading up about this subject and wondered if the fault isn't in the coil itself but possibly that some of the aftermarket coils have cheaper insulation making them prone to failure from too much heat. I may try a cheap set and try wrapping them with some duct tape or other form of insulating material and see what their life expectancy is. It may take awhile to get some results but if one fails within a year then we'll know a little more whether it works or not.

 

Here's a link to our special Ebay offer for the above mentioned coils.
Jaguar XJ6 XJR XJS Ignition Coil LHE1510AB Made In Japan!! True OEM

 

I originally replaced mine with an off-brand (buyautoparts.com) they dropped off in performance quickly! I bit the bullet and got the real deal ones from SNG on Ebay. BIG difference. The car screamed when I floored it. Don't go cheap, it will just cost you.

 

We recently replaced 3 coils on our 97 XJR. Viewed a you tube video on testing 2 wire coil-on-plug, and used an inexpensive Spark gap tester Purchased from Auto zone for less than $15. It has an adjustable gap by threading in and out; video suggested purchasing one with a "30" setting. The one we bought has a setting from 10-30 ( I assume it must mean 30,000 volts, since the gap over 1/2 inch). Easy to test with the car running, just remove only one coil at a time, connect bottom to earth with a jumper cable and leave the top of coil connected to wiring. If it jumps the gap consistently, it is working. If intermittent, or no spark, it is weak or dead. We found one not firing, one intermittent, and two that would work consistently at the 20-25 setting (weak). The advantage to this method is actual real time visual testing, that can be done quickly, and can identify ones that may be working now but are weaker (and probably on their way out). We went to a local salvage yard and bought 6 from a donor car for about $14 each, and tested them on our car one at a time right in the parking lot. Had any not been good, we could have returned immediately for credit. nice to know we have some inexpensive spares that can be replaced quickly and tested easily without spending hundreds in replacement bingo. Will try and post pics later.

 

Would you also post the web address of that video. I think you have hit on something.

 

How do I get my hands on a "spark gap tester", sounds too good to be true!

 

Adjustable ignition coil tester on Ebay
Adjustable Ignition Coil Tester Spark Circuit Tester Securely Avoid Fire Tool US | eBay

 

Many thanks. One on order.

 

What about the video.