Hi all, my 2008 XF SV8(4.2 SC) is due for new spark plugs, and even though I've gone through the workshop manual it doesn't explain to much on the removal process or what tools I'd need. I've changed spark plugs on previous cars, but those engine bays weren't as cramped.

Does anyone have any experience in changing the spark plugs and could possibly help me with it please? Much appreciated

 

It's not complicated, just somewhat cramped. I don't recall needing to move much out of the way, it might be easier if you remove the fuse box on the r/h side and maybe even the coolant reservoir on the l/h side but from memory it might not be cramped enough to justify doing that. The coil-on-plug units are each held on with a pair of 10mm bolts and the wires unclip to get them out of the way. The plastic cover pieces come off easily without tools but can be awkward to wriggle out once unclipped. You'll probably need a 3/8 drive spark plug socket with a short extension and maybe a uni joint. I like to blow the recesses out with compressed air before removing the spark plugs. Really there's nothing more complicated about removing these spark plugs than any other, and like with any job on these cars it's just a matter of removing what is in the way until you can remove what you came for.

 

Moving stuff out of the way was more so what I needed to know just incase I did indeed need to move anything. It looks quite cramped in there haha, I've read that the rear plugs and coils are a bit of pain to get.

Thank you for the help, really appreciated!

 

I also grabbed some anti-seize and dielectric grease for the plugs and coils as I've read that they're a must.

 

I did this a month ago. Like POD XF says, its a bit tight at the back.

Pull the supercharger and coil covers off. to get access to the coils and plug holes. I undo the coolant and power steering reservoir so you can move them a little out of the way. The first 3 cylinders on the right bank come out relatively easily, the first 3 on the left bank need a bit of wiggling to get past the coolant and steering fluid tanks. The two at the back are a pain in the backside because there's almost zero clearance. I used a various combinations of short, medium and long socket extensions with a uni joint. A 3/8 plug socket and short extension bring it to just below the level of the cam cover. I also needed a magnet on a stick to pull the plugs out from the back because the socket with the plug still in it is too long to come out of the rear two cylinders together.

You want to make sure the spark plug socket doesn't grip the spark plug too tightly otherwise when you've tightened it you can't wiggle it off and remove the socket from the plug well (I have two sockets and one grips its too tightly to get it out afterwards)

If you want to make it easier you can remove the screen scuttle, but that involves removing the wipers etc, so I just elected to remove the skin on my knuckles instead. But managed to replace them in just over an hour.

You need to make sure you get the right plugs for it, it only takes one type, the NGK Iridium ones (NGKIFR5N10). Hope that is useful.

Also worth checking if you have oil in the wells, I don't know when you last changed your cam cover gaskets, but they seems to last about 100K/8-10 years then leak all over the place.