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I have 70,000 miles on my car now, probably should change out the spark plugs. If someone has or knows the procedure to change plugs on an 09 XF SC would they please post it up?
Nope, 100,000 miles is the spec. I do not recommend you try this yourself. There is a strong possibility a plug or plug will be seized. Only one plug change every 100,000 miles warrants expert replacement. Iridium plugs are amazing.
It's an old V8 motor. You can see the valve covers and COP (coil on plug units) when you pop the hood. Pull the COP units off and go at it. Use anti seize on the new plug threads and dielectric grease on the COP boots. Make sure the plug gap is set correctly. Personally I hate Bosch plugs (specifically the +4 plugs). I've had nothing but trouble with them in Ford V6's I build (random misfires). I've always had good luck with double platinum Autolite plugs in everything I've put them in so I tend to stick with them.
Why would the plugs be seized? I have never seen this in 50 cars I have owned, do our cars have an issue with this happening? If so, what is the solution? If plugs seizing is an issue should we not pull them out and apply anti seize sooner rather than later?
Changing spark plugs seems to me to be something a do it yourselfer should be able to do. I pulled off the plastic covers that hide the coils on the cam covers, looks pretty tight in there but it should be do-able. May have to move a few things out of the way (if possible) to create some more room to work.
I will post how it goes, lets hope none of the plugs are seized, if they are I suppose some words with the dealer will be in order as I am out of warranty.
Plugs should not be seizing in place on a modern vehicle!
I agree with Blackcoog on the plug choice. I've loved the double-platinums and they seem to be a great choice to replace OEM plugs (the OEMs are most likely double platinum as well). I also agree with jagular though on the mileage, they should be good to 100k. Double platinum replacements should give you another solid 100k miles.
Some people say those fancy-schmancy will perform miracles, but your personal experience may be the best judge to decide what you feel comortable with.
The ends of the plug threads get carboned up. Then when you try to pull the plugs the carbon can cause the head threads to strip. I saw this on a recent Motorweek. Goss'sGarage. He actually advised you loosen the plugs very slightly and then fire up the engine briefly. This apparently blows the carbon out of the threads. Then you shut down and slowly turn the plugs out.
It is not really seizing but plugging of exposed threads with combustion byproduct.
This is why you should remove plugs slowly, progressively and carefully.
The ends of the plug threads get carboned up. Then when you try to pull the plugs the carbon can cause the head threads to strip. I saw this on a recent Motorweek. Goss'sGarage. He actually advised you loosen the plugs very slightly and then fire up the engine briefly. This apparently blows the carbon out of the threads. Then you shut down and slowly turn the plugs out.
It is not really seizing but plugging of exposed threads with combustion byproduct.
This is why you should remove plugs slowly, progressively and carefully.
Thanks jagular, this is very good information, I have watched Motorweek since it first aired, great show! I must have missed that episode.
My research shows and you stated earlier that the OE plugs are Iridium, I ordered the Bosch Iridium plugs, found them on Amazon for $5.98 each plus there is a $2 rebate per plug, combine this with free shipping and the 8 plugs will only cost me $31.84. Combine this with my own labor and I might as well pull the old plugs out and stick in the new ones. Many places charge 2-3 times that for Iridium plugs!
I realize the plugs should last 100k miles but I always cut those recommended numbers down and since it doesn't cost much and I get peace of mind I figure 70k is plenty of miles on the factory plugs.
Blackcoog is right no major issue to do the plugs. Make sure you adhere to proper torque settings and put some antisieze paste. I'm changing mine at 40.000.
Blackcoog is right no major issue to do the plugs. Make sure you adhere to proper torque settings and put some antisieze paste. I'm changing mine at 40.000.
Would someone in the know please post up the torque spec for the spark plugs on the 4.2 SC motors?
I careful drove it to the shop where they charged me 68.95 to order and install the hose for me...but even with that, I still saved substantially over what the dealer was going to change me, and learned something in the process...
Had I found the part number prior to taking it to the shop, I'd have likely ordered it and installed that myself as well, but better safe than sorry...
I have nothing but trouble with the bosch +4's when it comes to a boosted application.
They never seem to work quite right under load, like the increased pressure is "blowing" the spark out.
Good information, I wish I could have gotten good info when I replaced my plugs on my 1995 Jag, VP. Couldn't find any info on how to replace them. But I finally got it done, and did it myself.
In the process of doing mine, definitely NOT for the faint of heart. Started mine last night and have Just got 3 done on the drivers side, modding tools at work tonight just to finish..lol
My take on doing the plugs on my XFR. It's not a hard job, but VERY involved, I'm about (40% done over 3 days) I took my car down as I knew I could leave it down. I'm in no hurry. But 3 things you will absolutely need at your disposal are the right Tools, Plenty of Time and some automotive knowledge.
The list of things that need to be removed just to do the drivers side bank.
Air intake
Air box breather tube
coolant recovery tank
PS res, moved out the way
fuel lines disconnected
Then the cover needs to come off, and to get it past the last coil on that side you'll need a heat gun to soften it..LOL
and to remove that back coil will require a cut off #30 torx bit as it is too tight to fit a normal size anything..LOL
Oh and I'm thinking this was the easy side to do room wise..lol
Just the investment in the needed tools alone (I have most from my Camaro racing days) is not worth it, just let the dealer do it for most. I'll post pics soon.
What I'm putting in, mine had NGKs (6point 14mm) If you have Bosch's you'll need a 12 point 14mm Plug socket.
The view of that back coil with literally no room to work..lol
With the work area exposed, and the new plus in. I also replaced the coils torx bolts with 8mm head Flange bolts, much more forgiving and easier to work with. An old GM LS motor trick.
The rubber cover took me 2hrs to get off as Jag installs the engine from below with the cover installed (T Y How It's Made).
05-29-2012, 09:12 PM
