Hi All,

My XJ with 76,000kms pings and rattles under light load, but it doesn't do it at start up or idle, nor under heavy acceleration. I use to run it on 95 octane and have changed to 98 permanently, but makes no difference.

Any ideas how to stop this and what the fix is??

Cheers.

DJ.

 

Firstly welcome to the Forums.

When time permits, please do an Intro in the New Members Area.

I have no idea on that engine, BUT, a simple re-ask in the X350 Tech section will have answers flowing.

Also there is a heap of info in the "Stickies" at the top of that section that may even have the answer.

 

98 is no fix as 95 is good enough so...

Have a look with OBD live data.

(Of course check for codes but you may have none.)

Check sensors you can grasp (IAT, ECT, ...) and then check how quickly from start it changes from OL to CL (open loop to closed).

Check all monitors have set (you should have a pending P1111 code).

Look at fuel trims if CL. Hot engine, parked, at idle.

My suspicion is all will be well and it's not pinging but something else.

 

Welcome to the forum Mister550,

I've moved your question from General Tech Help to X350 forum. This is the place to post technical questions about your model.

Please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some information about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

 

TSBs are on this site and Gus has them on his site as well. They should be the first thing investigated when looking for answers to questions. Jaguar addressed many issued over the years.

It might not be the exact answer but this might help diagnose your fault..

bob

 

There's been occasional threads on the 4.2L pinging. My engine is also one of those that pings. It seems to be luck of the draw as to whether you get an engine that pings or not. I also don't think there's been any conclusive answer as to what is causing the issue (if there is even a common cause).

On my vehicle, I had the dealer do the PCM flash (TSB for 2006 models cited previously). That helped very little. Dealer also diagnosed a bad MAF sensor--a new one did not change the ping. I've checked cooling system performance, done top end cleanings, hunted for air leaks, intake gaskets, PCV system components, etc. Long story short, you can fire the parts cannon at these engines and not have anything to show for it.

Others have suggested aging/lazy O2 sensors, so if you're inclined to change those it might be worth a shot. Possibly having the injectors checked/cleaned/balanced would help.

Mine's been pinging on light throttle for over 70k miles now. Never on heavy acceleration. Annoying, yes. But it hasn't been an issue otherwise.

 

High performance engines like ours will never perform like they should with corn alcohol in the gasoline. Our idiot leaders are responsible for these stupid, fuel issue galore causing, criminal laws. Sunoco 260 was great fuel, the highest octane short of racing fuel available, at the time. Engines loved it as well as the fuel systems, cold winter weather was never an issue with it either. The octane if memory serves in Sunoco 260 was 96.5. The minimum called for in my Triumph motorcycle was 96, Sunoco 260, just made the grade, think about that a while, just how bad fuel has become.

 

Hi All,

Sent car to Jaguar for reflash, it improved the pinging by maybe 50% and was told to change fuel from Mobil 98 as it' not a great fuel apparently. Also to give car a long runs to try burn off carbon build up.