1999 XJ8...68,000 miles when timing chain tensioners were replaced.

4/20/2010...and 78,000 milies auto at Manhattan Jaguar [Rockville, Md] mechanic can not located where the pinging [chain dragging] sound coming from the engine.

I too believed it was a low octane level but we always use premium gas.

Jag. Dealership stated; found metal shavings in the oil [nothing new to me...most oil have metal shavings] and that the wearing or sound may be in the lower part of the engine.

Jag. Dealer wants to perform 10 hours of work [@$120 per hour] to open the bottom of engine to find the source of the noise/metal shavings wear.

NOTE: 1) no knock sensor light coming on
2) can hear the chain-dragging sound at low acceleration

Called my Jag buddy at Glenn Burnie, Md. stated that the lower tensioner may be faulty.

At this blog time...Jag. Dealer is going to use some type of stethoscope to find the pinging sound/chain dragging sound...only at low acceleration and then it vanishes. May hear it again when a sudden, steady press on the gas after maintaining a high rate of speed.

What is the problem? Chg.

 

SteveTech...

With this pinging/chain dragging sound and no knock sensors going off...do you;
1) continue to drive the jaguar

2) pay the dealership $1,200. just to drop the bottom part of the engine to locate any metal shavings or wear

3) put fresh "premium" gas in the tank...at one time I did suspect water was in the gas tank . Several months ago the jag stalled and Dealership drained the gas tank and found water [put in a new gas pump].

The wife still goes to the same gas station after my warnings, warnings and warnings. She declare she will find another gas station after this current episode.

4) drive it unit it drops...dead then purchase another engine???

 

Hey there, is there any update to this issue. Was there a fix for the knocking sound.

 

this sounds just like what my 05 XJR does currently,, have you reached a conclusion?

 

Would like to revisit this by adding my own pinging to this thread. My 04 xj8 has begun light pinging at slight throttle but it goes away if I lean into it. This is around 1800 RPM. If I downshift to get Rs up above 2K, pinging stops. There is no MIL or CEL as some call it. My plan is to just replace the sensor which should not be stupid expensive but where is it? Can it be gotten to without major disassembly of intake system?
My car runs great with 115K miles. Here is pic I took on lonely interstate 8 a couple weeks ago around midnight.

 

I would recommend a couple of things. One, remove the PVC valve, and get some parts and brake cleaner. Spray in both openings and shake it a bit with your fingers covering the openings. Do this a few times, and insure you hear rattling when you shake it before reinstall. Then get a can of 44K or two pints of Techron and add to a full tank. Buy the gas at a different station. Keep us posted.

 

I too have had this pinging issue for as long as I can remember. Symptoms exactly the way you describe. It's worse during the summer, and especially at higher load, like going up a hill. Might be due to the heat or the summer fuel formula. I suspect the knock sensors may be weak, but like I said, this has been going on for years; I imagine they would've failed by now. Unfortunately, you have to remove the intake manifold to reach the sensors, so it is a very involved process, but doable. I've heard all sorts of reasons: carbon build up, knock sensors, overheating, catalytic converters, O2 sensors...could be any of those.

I run a can of BG44k once a year, I replaced the PCV valve about two years ago, and have tried every different gas station. None of it makes a difference in my situation. I'm not sure what the best way to clean possible carbon build-up is so I haven't gone down that route. Engine doesn't overheat, so it's not that. I am installing Nameless cats and new O2 sensors soon, so we'll see what that does.

Edit: I have noticed that it does become more pronounced if you're running lean. I had lean codes pop up last year and the pinging was really loud. However, I still get the slight ping even if my fuel trims are on target, as they are currently.

 

I can commiserate with XJ8JR--my 2006 XJ has done exactly the same thing for years now. Replacing all seals in the PCV system and the oil fill cap has fixed my fuel trims, but the pinging never really changed. Have done intake manifold gaskets, MAF sensor, had the PCM flashed, never made a difference. Even paid the dealer for a diagnosis with no results. Only thing haven't done is knock sensors, 2 each under the manifold, and no inclined to do those on a whim. They are not inexpensive, either.

The PCV valve is a fixed orifice, it won't shake/rattle when you remove it.

 

Its just about time for my yearly fuel treatment, but instead of using BG44k as usual, I just picked up a bottle of Techron and dumped it in before filling up. There's a specific part of my commute where I always hear a slight ping, and I haven't heard it since using the Techron yesterday morning.

Now, I've used Techron before with no luck, which is why I switched to BG44k, but there seems to be some effect this time. It's probably just temporary, but we'll see.

 

You should've done the knock sensors while you had the manifold off. I would've done that by now, along with the coolant valley hose, if I had a proper garage to work in. But hopefully I'll be moving soon to a house with a totally private garage and I'll be able to check everything off my to-do list.

 

My local oreilly auto parts does not carry the bg44k but they have several techron boosting products...are they all the same or which specific one did you have recent success with? So glad to see you are at 150K on your xj8L.

 

Hindsight... but at the time I was pulling the manifold for the valley coolant hose, and I think the knock sensors are $200 each? Not sure, but not something I'd do on a whim. I have heard from a Jag tech that the knock sensors can go bad over time. Not sure what you can do to verify that.

To be honest, the pinging I hear on mine is not the type that would risk damaging the engine, and the sensor/PCM may ignore it. Just annoying that a Jag V8 pings at all.

Amazon is where I got mine. It's not something you will typically find in the part stores. I believe bg44k is what Jag recommends, though. I've done 3 cans of it and it made no difference.

 

Unfortunately, BG44K has to be ordered online. I've been dropping a can in once a year for the past few years. Never really noticed any difference in performance before or after. Maybe that just means my system is clean already!

Although, like I mentioned this morning, the Techron seems to be reducing my pinging, for the time being at least. I used the Techron Fuel Treatment bottle with treats up to 20 gallons. Bought it was the Chevron station.

 

Well that didn't last long...the pinging is back. Not any more or less, just as usual.

 

Id take a look at the cats or better yet just replace them.
Given the miles you will have on the car they will at best be partially blocked.
Id recommend using 100 or 200 cspi units

Take a look here https://www.jaguarforums.com/forum/x...solved-137070/

After everything from pcv valve, sensors (including knock) were replaced it was new cats that solved it

Cheers
34by151

 

I totally agree. I'm still waiting for my Nameless cats to arrive.

 

I just went for generic 100scpi units which are a fraction of the namless price These are 3in units that I had welded in. Im runing 3in pipe to the cats and 2.5 for the rest.

Cheers
34by151

 

Unfortunately, here in California its nearly impossible to find easy generic replacements without paying an arm and leg...and that's if vendors will even ship to you! So, if I'm going to pay an arm and leg, I might as well make it easy for myself and just get the Nameless cats, which I can just bolt on myself instead of having someone do a bunch of welding. I agree there are cheaper alternatives out there, but the Nameless cats are just easier and more convenient for me.

 

Has anyone looked at the TSBs for this fault???????????????? They are in the large file area for download.
This has been a known issue for 12 years now.
There are software upgrades since June 2004. There are AMENDED TSBs thereafter.
XJ303-04
XJ303-04 AM
XJ303-09

Each successive TSB recommends reconfiguring the ECM with a later version of software.

There might be later versions of software but I left the Jag Dealer about 10 years ago so I have no more access to later info.

bob

 

Thanks for that info, Bob. I never would've found those. How does one go about getting these updates? Do you just go to the dealer and show them the TSB? My only concern is that my local dealer is manned by a bunch of con artists. I have no way of knowing if this update had already been done before my ownership, and I have no way of knowing if the dealer will actually perform the update instead of just saying they did and taking my money.

Also, I just noticed that my VIN is outside of the range specified.