Hi all, I'm Terry and new to the forum. I've read so many posts on here and as I own a 2011 XF 5.0 N/A(2nd owner) , I thought I'd join ​​​​​​

I'm very hands on when it comes to car maintenance and doing car services.
My car is just about due for a service, I've searched YouTube for tutorials on how to access the spark plugs to no avail. Everything else is pretty straight forward.

Any help at all would be greatly appreciated! Thank you

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Welcome to the forums Terry,

Both this and your Intro post were automatically locked for moderation. I can't see a problem with the content in either and have unlocked them.

On the 5.0 V8 the spark plugs (item 3) are hidden under the plastic engine cover and NVH (Noise, Vibration, Harshness) covers beneath that. The engine is 'coil on plug'. This is from the XK Workshop manual but the same 5.0 unit is used across the model ranges.





Each ignition coil (item 4) locates on a spark plug and is secured to the related cylinder head cover with a single screw. Each ignition coil has a three pin electrical connector for connection to the engine harness.





Graham

 

Thank you very much! Is the plastic engine cover just the beauty cover that sits on top of the motor?
Are there any instructions on how to remove the NVH?

 

The cover on top of the engine lifts off quite easily from the front.

The NVH covers are a softer rubberised plastic that covers the coil units. They are simple to remove once the breather hoses are removed.

Remove the wiring loom connectors to the coil units by squeezing them GENTLY.

The spark plugs require a 14mm socket spark plug socket. It's also a good idea to have a locking extension so the spark plug socket can be easily removed once the new spark plugs are in place.

 

One other point to make here: when installing the Torx screws for the coil units, torque them to NO MORE THAN 7 Nm.

 

Thanks so much! That definitely helps a great deal.
I don't have a torque wrench as yet but will be getting one very soon.

When swapping spark plugs, would it be best to stick with OE, or go with well known brands like NGK, Denso as long as they're the correct fitment?

This is my first Jag so I want to make I'm doing everything properly!

 

I believe the OE are NGK anyway but even if they are not you can't go wrong with NGK as they are at least as good if not better than OE if OE are not NGK.

 

Ah okay, I didn't know that haha.
From what I've been able to find, Iridium tip are the recommended option. Has anyone found any difference between normal Iridium and Twin Tip Iridium plugs?

I did find some DENSO twin tip Iridium plugs, haven't purchased yet however.

 

Mate,
Get yourself a copy of the AJ133 Technical Training pdf from my Dropbox here: https://www.dropbox.com/s/8y4iax9hm2...%20V8.pdf?dl=0
It covers both the NA version which you have and the SC version and is chocko with all sorts of useful info.

 

Buy the spark plugs of the same brand that came with your car.

 

Having done this job I can tell you with certainty that you will want to move the plastic shroud for the fuse panel out of the way. You need as much room as possible. You'll want to disconnect the injector harness. The rubber panels are a major pain in the *** to get back in right. I trimmed the right bank up slightly. Some sort of lubricant on the outside would probably help. It's a major pain in the ***.

Make sure to gap your plugs properly.

There's a pretty good guide by one of the more valuable members here.

Make sure you have wobble extensions and the right tools, the t25 or 30 but for the coil packs. Handle them with care. But extra torx bits in various lengths.

 

I've read in a couple of threads that the rubber panels are a bit of a pain, but more of a pain to get back in place.

I can't seem to find anything about the plug gap anywhere. Different sites that sell plugs have a gap of . 040 and .045 I think it was.

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That Denso listing you posted shows a gap of 1.1 mm (which is .043 inches) which from memory sounds right to me.

 

No such thing as gapping spark plugs on modern engines. The high precision tips are extremely sensitive and should not be touched. You want to buy the same plug as it came from the factory with and it will be pre-gapped to the correct spec. According to the shop manual the model number is ILKAR6C-10, which comes up as an NGK 95843, now replaced by NGK 94940 ILKAR7C10.

https://www.rockauto.com/en/catalog/...park+plug,7212

There you go on the bottom, even says "Actual OE Manufacturer".

 

That is 100% false and misinformation.

You can gap plugs to fit your car. It is incredibly important on forced induction vehicles. No, you do not want to grind down the center electrode, you gap using the side electrode. You should use a feeler gauge set and not the silver dollar sized cheap gapping tool on the counter at most auto parts stores.

On my XFR I gapped a similar to factory plug (Champion Iridium) in the correct heat range, to spec.

 

Yes plugs come pre-gapped these days. So I only check them just to be sure. But the ones I have installed have been fine.
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+1

The centre electrode is very delicate.

 

Thanks so much for the help!

 

I find a magnetic pickup tool is handy for pulling the plugs out once undone.

 

I've used vacuum line to reinstall the plugs helps to finger tight them before putting the socket back on