For a while now I've had this ticking issue in my engine. I've also had to deals with an armada of bushings that has failed. Lately I've worried about the engine and upgrading because of small issues(ticking) and really thought I'd have to sell mine off and get another. TODAY however... I decided to swap out the spark plugs for NGK Iridiums. Let me tell you... the difference has been stellar. Not only in performance, but because I accidentally found the ticking issue that was caused by a spark plug that came totally out. It was rattling as the car was running.

This is a testament to the engineering in the 2002-03 XJ's. They are SOLID. I have put the top brand in oil and fuel for nearly 6 years in my XJR and I really think its paid off. At 146,000 miles, she is so smooth and refined, yet I punch the gas she screams. Obviously, the car has some shortcomings, but those issues are being addressed by Twin Screws, upgraded HID's, lightweight rotors, etc etc. I'm determined to make this car right while all my friends have ridiculed me for spending time and money on this car. There are days I want to throw it in the the Gulf of Mexico, but there are days like today that I am completely satisfied with it.

I will proceed with performance upgrades, interior leather/lighting upgrades and tightening her up and will enjoy that damn car for another decade at least. And screw BMW's.

 

It wasn't the rattling. It was blowby right out the sparkplug port. There is a 4 or so year old thread still active on bimmerforums about this exact problem.

Red October hit it on the head in your original thread https://www.jaguarforums.com/forum/x...k-plugs-90109/

What brand was the loose plug?

 

They were Bosch plugs

 

A 2007 XKR just out of warranty had almost all the plugs blowing, cooked coils and boots.

How did the boot/coil look on removal?

Happy to hear it's sorted very rare for the valves to need a re-shim, dodged a big job there

 

hmmmmm i just put Bosch plugs in, and thats really when i started noticing the ticking issue on my engine...... now you got me wanting to get some OEM NGK plugs

 

The boot was caked in dark charred residue but was ok when I cleaned it off. They were installed new about 2 years ago.

 

Those Bosch were the culprit to many restless nights thinking of that damn ticking. Open them up and check them, takes no time really. Locate the ticking to the general area and open the nearest couple spark plugs.

 

The reason I asked first is that there is a small contingent on JF who do not like any negative comment about Bosch plugs.

The problem of loose plugs seems to be well known on bimmerforums ... and the owners almost all say that the plugs were Bosch. They change out to ... NGK.

 

i will most likely give this a try when the weather gets a bit warmer

 

Well that small contingent can debate it all they want, but my experience(which was well, well documented) with the ticking engine was a direct cause of those bosch spark plugs coming undone. I was going around to mechanics and dealers, getting thousands of dollars quotes, changed the oil 4 times, put additives in the gas and oil... did everything.

I'm not and engineer or spark plug critic saying NGK are better, its just my specific mechanical troubles which were caused by Bosch coming loose.

 

Just wanted to say thanks princemarko, plums, sean B, and JHartz. Once again the info here on the site prove to be invaluable.

I've owned my 02 xjr since April of this year with no real issues other than some ticking and a slight rough idol, until last week... when the check engine light came on... I bought an OBDII scanner (actron CP9575) found two codes P0172,P0175 (rich fuel mixture both banks) and started scouring the threads here at JF.

Yesterday after reading this thread I popped off the dust cover for the coil/plugs on the left bank. On the underside of the cover I found oil spatters like if you blew them there with a drinking straw... this morning I checked the right bank and found three such spots on that cover. I swear I could have unscrewed 4 plugs (2 on left, 2 on rt.) with my fingers, basically I did with the extension. And two more were barely snug! All six were in a puddle of course, the other two were quite snug, but not tight. Sorry to report that loose plugs were NGK IFR5N-10, replaced with NGK BKR6EIX-11. Upon starting the ticking was gone, and the idol a smooth purr. I bought the car in April of this year and have very happy with it's performance, and I qualify as a "spirited driver" as some here would say ;-). I took her for a spin and all I can say is the difference was stunning to say the least! My 13yr old son's words were "Holy Crap!"

My fuel trims are hovering at very near zero,(thanks JHartz) and I'm betting I wont see that light again soon. Marko you're right on with being impressed with the engineering on these cars... I'd bet I've been driving with this issue since I drove it home from Florida to Mich. four months ago, with no real issues beyond a slight rough idol and some ticking that sounded no worse than an injector! People think were crazy? I say crazy like a fox for the money! I'll continue to love my car too....

Thanks again to all...

 

Thanks to sparkenzap too, his threads and links to articles on fuel trim are great!

 

In a way you are lucky ... the previous owner may have sold the car due to the problem, and the potential expense of fixing it.

BTW, the oil in the spark plug wells means that you need new seals on the spark plug wells that sit in grooved rings under the valve cover. It's a simple DIY job. Two hours max per side working really slow.

 

Oh trust me I know how lucky I am, and like I said thanks just does not convey the gratitude for the guys that post here. Grateful I am!!

Thanks for tip on those seals, I noticed that a few of the bolt heads on both of the cam covers have some oil on them too...new gaskets needed there.

Are those seals part of a set when I purchase the cam cover gaskets?

 

Usually. Word on the street is that the Felpro set is not quite thick enough. I bought the Victor Reinz set which has the seals as well as the seals that go around the individual bolts. Don't ask if they're thick enough ... still in the packaging.

 

Simple....there is your reason.
The factory install NGK as OEM for a reason....they are the BEST!
Use a small dab of nickel anti-sieze on 180deg. of bottom half of the threads and
tighten to 18-20lbs/ft.
Make sure all plug wells are free from oli.
If there is an excessive amount, you need to replace the cam cover oil seals.
And usually oil leakage is caused by engine part load and full load breathers not being cleaned at regular intervals.
200,000 klm and mine is as tight as a drum and still using the original coils. ;o)

 

Well, that's the correct spec and I agree with it in principle as well as practice ... except that I use the angle torque that I have observed as being consistently equivalent.

The problem is the instant experts who will dig up the NGK USA brochure telling ham-fisted users not to use anti-seize and the mumbo-jumbo about anti-valent coatings.

 

Heeejhee...yes Plums....you're right but hey, in 7 years ownership doing all my own 'wrenching' and 200,000klm without probnlems suggest I must be doing something right ;o]