Hey sweeties.

Just hit 98,400 miles.


Honestly haven't been driving the car much as of late, but a small tune up may be in order.


Oil change a few days back (Castrol Edge full syn, I forget the filter brand).


Suggestions?



What brand coil packs do you guys recommend, (AJ83415), NGK Iridium plugs?

Thanks guys, car is running just peachy.

 

One, look at Pennzoil's new Ultra. Second, use Mobile 1 M1-213

 

I do not know if changing coil packs will help. The Iridiums are about as good as it gets.
I am partial to Wix oil filters, but use more Mann in my vehicles.
A fuel filter may be in order also. Plus a couple cans of fuel injector cleaner.

 

Hi Naso,

The OEM spark plugs are NGK Laser Iridium 7866 (IFR5N10). Members who have tried other plugs (even other NGK plugs) have reported mixed results, so as far as I'm concerned there's no reason to use anything else.

Mann makes the Jaguar OE oil filters, but I also like Wix.

I've always used Castrol in our Jags but any high-quality, name brand synthetic oil that meets Jaguar's specs will be fine.

The OE ignition coils were made by Denso (they are individual coils-on-plugs for each cylinder rather than multi-coil packs). I was not able to find a source for the correct Denso coils, so I ordered samples of both the Airtex and Standard Motor Products coils from Rock Auto. The SMP coils appear to be of very good quality, but since the Airtex coils are marked FoMoCo (Ford Motor Company), and since they're less expensive than the SMPs, I've ordered more of the Airtex coils as needed. The Airtex part number is WMA 5C1420 and the Rock Auto part number is 5C1420. For some reason the price at Rock Auto has varied, and I've paid anywhere from $35 to $45 per coil. They're currently listed at $39.79.

If you're rolling in cash, it certainly isn't a bad idea to replace all the coils on a decade-old car. But the strategy I've adopted is to replace each coil as it goes bad (3 so far), and to always keep a spare new one in the trunk because they seem to always fail while I'm on a road trip. Eventually they'll all be replaced, but I won't have to pay for all of them at once.

That's my two cents. I always enjoy reading the opinions and experiences of others.

Cheers,

Don

 

Don, the 7866 is a very fine plug. I'm currently using 5464 (BKR5EIX-11) @0.037, indexed and ground electrode mods/polish. I have good results with this plug. The prior owner for some reason had Platinum Motorcraft 32's in it.

 

Thank you guys for the recommendations it is very much appreciated.

 

David,

I can understand why you'd want to use a less expensive plug with a nickel ground electrode instead of platinum if you are going to index the plugs. How many plugs did it take to get 8 indexed, or did you just use washers of different thicknesses?

For the 7866 NGK recommends a gap of 1.0 mm (0.039-0.040 in.). For the 5464 they recommend 1.1 mm (0.043-0.044 in.). Did your choice of a narrower gap (0.037) have something to do with the indexing or polishing (I've never done either myself)?

Did you dyno test to determine whether the AJ33 N/A responds better to the plug gap facing the intake or exhaust valves? Just curious to learn about the process.

Thanks!

Don

 

Concerning the plug itself, NGK allows 0.008 variance in it's electrode gap, and 0.037 is what Jaguar recommended. The radius is deburred and lightly polished. At 11:1, 0.037 is about right for good idle. The old one's had opened up to well over 0.060. I guess you can imagine how well it idled.

The way the chamber flows, down the stem on the intake side, (tulip) and across the exhaust valve, (nailhead) the better placement is to split the electrode between the exhaust valves. I do not have access these days to a chassis dyno, man I wish.. However, I have done enough at the flow bench on both 2 and 4 valve hemispherical chambers for decades, to know there are some very repeatable and predictable outcomes to setup.

I was very lucky when indexing, because after seal crush, you have about 2/3 turn between 15~20 foot pounds. I had to use one 60 degree washer. The rest were very manageable.

 

David,

So if I understand correctly, Jaguar recommends 0.9mm-1.0mm (0.035-0.039 in.) for the 7866. But since NGK recommends a gap 0.1mm (0.004 in.) larger for the 5464 relative to the 7866, wouldn't that suggest the correct range for the 5464 in the AJ33 would be 0.039-0.043 (adding 0.004 to each end of the 7866 range)?

You know far more about this than I do, so I'm interested in your thought process and/or theory in determining the smaller gap and how to predict the correct gap for good idle relative to engine compression. The N/A AJ33 is 11.0:1, but the S/C engines are 9.0:1. What adjustments in the gap would that suggest to you?

The nickel 5464 is definitely a more affordable alternative to the platinum 7866 and I would assume the only difference would be a theoretically shorter lifespan (possibly insignificant in practice)?

Thanks,

Don

 

One thing worth mentioning in this thread is that Jaguar recommends the use of nickel-based anti-seize compound on a portion of the spark plug threads, but NGK does not, at least since the advent of "Trivalent" plating. According to NGK, the use of anti-seize can act as a lubricant altering torque values by up to 20% and potentially leading to thread damage:

http://www.ngksparkplugs.com/pdf/dyk_5points.pdf

Before I found this NGK document, I followed the instructions in the dealer training manual or workshop manual and used nickel-based anti-seize. Oh well.

Cheers,

Don

 

The trivalent plating has been a matter of debate before.

I think you will find that the NGK documentation on the ROW
sites, including the master .jp site do not make any special
provisions for trivalent plating.

My take is that NGK USA had to allow for people who did
not pay attention to the finer points of fastener torque.

It is true that lubricants will alter fastener torque. That's
why I prefer the turn X degrees after finger tight method.
It is based on the same principle as torque-to-yield being
more predicatable than torque wrenches.

Of course, finger tight is a matter of judgement.

Here are the numbers I worked out, and use on a 4.0L SC:

I observed the amount the plug turned using a calibrated torque wrench and
the 1/2 turn matched well the first time. I use motor oil from the dipstick
since it is always "ready to hand".

Thinking of it just now, if one uses the Jaguar spec with anti-seize, the
effect of the trivalent plating is completely negated and can be safely
ignored since the anti-seize is much more slippery than any dry plating
could be.


Ford issued a TSB that is useful reading regarding the removal of sparkplugs
from aluminum heads. It addresses a problem they had with sparkplugs installed
without lubricant. The TSB calls for anti-seize after the check/repair.

http://www.phila.gov/fleet/Warranty%...-06%20FORD.pdf

The most important part of the TSB is that sparkplugs in aluminum heads must
be "worked" out if any unexpected resistance is felt. Otherwise, the thread can
be ripped out causing a unnecessary repair. Their preferred technique is given
in the TSB, so it is a worthwhile read.


++

 

I use Mann Hummel for all my filters these days just like the quality they also make Bosch and own Purolator these days a good combination
As for plugs I have been using theseBrisk Racing Silver Spark Plugs | Spark Plugs for 10 years now I have fitted them to every car bike anything with an engine very happy with them
I cant say how long they last I change them every 50,000 k,s which seems to take years as I live in town so only use my cars for trips away

 

Nice site, and they seem legit.

With a spare set of the new design Denso awaiting install,
it might be a while before trying the Brisk though.

 

Don, the gap on the plug will determine how many Kv's it is going to take to arc the plug. Fuel plays a part. Upper 30's in gap are great for idle quality. The size of the coil also plays a role. I'd stick to the gap recommended by Jaguar myself.

When gapped @ 0.030's and close to a decent fuel charge, it takes about 9kV to cross the gap, another few hundredths @ 3~4kV for burn time. At that point the magnetic field has collapsed and no more voltage. Most new coils can see voltages as high as the 40kV range, but most real world values places the coil's available voltages run in the 20's. A lean mix will increase the required fire voltage and you can get into the 12~15kV range real quick. That leaves little reserve for burn time. As you increase the gap, the more voltage will be required. At 40's on gap, expect 10~11kV, at 50~60's gap, you can easily use all the coil can produce, overheat the coil, and lesson it's life. Fresh plugs are good things.

 

Hi David,

Thanks for the technical info.

I may not have posed my question about the spark plug gap as clearly as I could have:

1. Given that you are using a plug that is different than the one specified by Jaguar, and

2. Given that the plug manufacturer, NGK, recommends a gap for the plug you are using that is 0.1mm larger than for the plug Jaguar specifies, then

3. Would it not logically follow that you should add about 0.1mm/0.004in. to Jaguar's recommended gap when you use the 5464 instead of the 7866?

My assumption is that the difference in NGK's recommended gap might have something to do with the lower resistivity / higher conductivity of the nickel used in the ground electrode of the 5464 compared to the platinum used in the 7866.

Thoughts?

Cheers,

Don

 

It may have something to do with application coverage.

In the NGK numbering system, the last two digits are the preset
gap in 0.1mm units. Therefore a BKR5EIX-11 has a preset gap
of 1.1mm.

There is no BKR5EIX-10, at least according to a web search,
so NGK might simply be presenting "closest suitable fitting"
and 1.1mm is it.

In the PDF you linked, NGK further go on to say that fine wire
plugs have a recommended adjustment range of +/- 0.008"
which is equivalent to 0.20mm, implying a coverage range
of 0.90mm to 1.30mm with the nominal 1.10mm preset.

The gap out of the box should be checked in case it got
a hard knock in shipping, but I'm not really fussed about
closing it up although I do like closer to 35 thou than
40 thou.

 

Don, concerning part AJ8 4575, many in the dealer network use also 5464 7866 BKR5E1X-11 C2A1535 C2A1535C NCA3850EA1 XP104 in their alternate part number classifications. 5464 is NGK's highest performance, and 7866 is their longest lasting. I'm not sure I agree with your assertion concerning item #1. Concerning #2, it makes much more sense to fit the plug to the chamber's requirement, not the chamber to meet the plug's requirement. And #3, this was my point in earlier posts, when speaking to a fairly high compression engine, 11:1 and the engine's performance at the lower end of the scale. Virtually 90% of the driving is done under 2,000 RPM. @ 75 MPH cruising, I'm still under 2,000 RPM. And high torque, high load, low RPM requires a different focus than if it was always WOT or track bound...

Concerning gap, 0.030's works well.

 

Hi David,

Can you provide some documentation for dealer use of 5464? I've tried unsuccessfully to find a cross reference that identifies any of the alternate part numbers you listed as 5464.

According to the EPC AJ84575 (also listed as IFR5N10 in some of the Jaguar service documents) was superseded by C2A1535 from VIN H16115, but C2A1535 is also 7866/IFR5N10, at least according to these links:

Jaguar C2A1535 - Alternative spark plugs
Spark Plug - C2A1535 - Genuine Jaguar at www.rimmerbros.co.uk

Neither C2A1535C nor XP104 show up in the Jaguar databases at jaguarmerriamparts.com or gaudinjaguarparts.com. NCA3850EA1 shows up, but supersedes to C2A1535 (7866/IFR5N10). Any documentation you can provide regarding dealer use of 5464 will be appreciated.

Cheers,

Don

 

Don, Really? Originally these (2761(NGK) 3275(Denso) BE-1 C2A1535 C2A1535B C2A1535C FR8DPX4 NCA3850EA/1 NCA3850HA1 PFR5G13E) were all Platinum plug cross-references before the introduction of Iridium. I hope you have a great day.

 

Hi David,

You obviously have advanced knowledge of automotive mechanics, so what I've been hoping to gain from all my questions is the theory, mathematical formulae, or other means of calculating spark plug gap based on engine compression, cylinder design, plug choice and any other factors you have mentioned in your posts; and since you are using a spark plug that does not show up in any of the Jaguar documentation I have in my library or have been able to find online, I simply wanted to know on what basis you made your choice. You stated that "many in the dealer network use also 5464" et al., yet provide no supporting documentation, and I have not been able to confirm this by searching two of the Jaguar dealer databases available online.

If your plug and gap choices are based on your extensive personal experience as a trained professional mechanic, that's great, but please say so, so others who don't have your knowledge and experience can factor this into their own choices. For the rest of us, including those members who are only beginning to undertake their own auto maintenance, it would be helpful to understand the theory, calculations, knowledge and/or references on which you've based your choices.

Regarding your latest post about all those platinum part numbers having been cross references before the introduction of iridium, given that NGK introduced iridium plugs in 1994 and, as far as I have been able to deterimine, Jaguar specified iridium plugs in the X350 from its very introduction in 2003, I struggle to understand the relevance of any pre-iridium cross references.

I am truly not doubting or criticizing you. I simply want to understand the underlying knowledge and theory behind your assertions and choices so that I and other members can evaluate their applicability to our own vehicles and driving styles. Without the knowledge you possess, the rest of us have to either take a leap of faith or remain unconvinced.

With your knowledge and experience, you are in a position to help the rest of us to better understand our Jags and the pros and cons of alternate and upgraded parts. I'm simply looking for more supportive detail and verifiable facts before I use or recommend a spark plug other than the one specified by both Jaguar and NGK.

Cheers,

Don