My 04 XJR has been pinging quite a bit, and I have read that the PCM update will fix this. However, I have dealer paranoia, especially at our local dealer. I just don't trust them. I called to see how much it would cost to get the update done, and I was quoted $112 and about 1 1/2 hour, as they wash the car too. Fine. When I asked if they had the info needed to address this issue, I was given the "we have everything there is, so I'm sure we do."
Ok, but I have this fear that I am going to take it in, get it done, and still have the pinging issue. I figure then they will tell me something else must be causing the issue, and let the $$$ fly.
How do I know for sure what to ask for and how do I prove I got what I need?

 

Well, I had the PCM flash done under warranty. It seemed to help the pinging some initially, but currently my engine is still pinging like crazy on light throttle. Coolant temp is at 195 F and ambient in the 40s and 50s F and the engine still pings. Have not tried diagnosing much further, unfortunately. Some guys on the XK section recommend using BK44 fuel treatment to help this issue. I tried Techron which made zero difference.

 

Any codes come up?

 

Nope no codes. I am wondering if maybe this isn't pinging we are all hearing. With the sensors the car has, I just don't know how it could ping. Is there anyway this is something else? Might that explain why none of us have luck curing it?

 

Just to eliminate the obvious - you are using good quality premium gasoline, correct?

 

Yup. Only Shell 93 octane.

 

Too low.

At least 95 octane.

 

I haven't seen 95 octane in the US for at least 15 years.

 

My understanding is that the US rating of 93 octane is the same as 95 octane in European standards. Either way, my point is that if we have antiknock sensors, should it really even matter? The car should adjust the timing to accommodate, right? I am just starting to wonder if we are getting tricked into thinking this is what we are hearing...

 

Old thread but, shouldn't really get it with a modern car.
but I've just noticed that mine is doing it badly during the first few minutes after start up and always at the 3000rpm mark pulling away from a junction on a hill. It sounds like the engine is chewing milk bottles. Once the engine is warm, it's OK.

 

Sounds like a fault worth diagnosing before it gets expensive. Best in the correct forum, though!

 

I'll have a look through the S Type section, but gathered this would be a general engine related issue rather than model issue.

It ONLY does it on a particular hill, within a few minutes of starting and as I don't usually drive the Jag to work, I'm not able to replicate it anywhere else?

I have had it put on testing equipment at a local indy, who advised there are no issues that are being flagged. He wasn't able to replicate it either, but he suggested some fuel treatment and an Italain tune up once in a while.

 

On an S-Type it's likely to be one of the usual suspects, covered in the S-Type forum. The forum you're in doesn't even have a car with the same engine...

 

OK, I'll move over to the S Type forum and see if I can find out more. Any pointers for me regarding the 'usual ' suspects?

 

Coils, air leak, MAF, O2s, cats, ...

Search/read for your symptoms. Get and use an OBD tool with live data.

 

Not as bad as I had been lead to believe by searching the web then. My symptoms, when I search, always go back to ignition issues or shagged chains.

I've got an OBD tool, but not that clued up on how to use it. I'd have reckoned on the indy being able to to pick up some codes or pointers, but nothing.

If I get the OBD plugged in and looking at Live Data, what in particular should I be looking for that would give me a pointer?

 

You really need to find a tech with a clue.

 

Thanks for that.