Though I use the highest octane fuel available (93) [I know, the octane on the 4.2 should run fine on 87], I am starting to hear engine pinging (NOT KNOCK) on initial acceleration and never at high speed or around 1,800 RPM] - sort of the sound I would have called lifter knock in the olden days (1960's or 70's) and would have adjusted the points gap and distributor timing.

Having asked around, the consensus is that I change the spark plug wires and the Knock Sensors first. The plugs and coils were replaced approximately 3,000 miles ago and I will inspect the gap on the NGK Iridium plugs as well as inspect the new coil packs.

Am I barking up the wrong tree?

Can anyone explain the cost difference between the Left and Right sensors. The Left is almost 3X the cost of the Right. Is there a function difference?

2003-2005 Jaguar S Type Knock Sensor - Right - Bank A - W0133-1655954 - $53.48 Partsgeek.com


2003-2005 Jaguar S Type Knock Sensor - Left - Bank B - W0133-1655837 - $141.48 Partsgeek.com

Also, is a plug wire a plug wire, or is there a significant difference between brands and types?

Thank you!

 

I doubt it should run OK on 87, but let's ignore that as it's not your problem.

It could be one or both cats breaking / broken up.

If you have the right NGK IFR5N10 plugs in then it's not going to be those. I would not remove them without a better reason and beware the electrodes are VERY delicate - easily damaged.

I can't see it being both KS - they last many years and for both to fail with no codes is just not plausible.

Coils are a suspect if non-OE ones were put in as they are known for reliability issues. I'm doubtful you'd get what you report, however.

You don't in effect have plug wires as these are COPs. Anyone who says you have plug wires does not understand or know these engines so everything they say is highly suspect.

I'd get an OBD tool with live data (elm327 - very cheap) and check for codes, pending codes and then look at live data for fuel trims - all in the hope of more clues.

 

I suspect you may be correct about the coils. As I don't relish the task of replacing them (the driver side rear two plugs and coils are simply 'ugly'), the scanner should tell me which cylinders are giving me the issue. I am looking at the KONNWEI KW808 OBDII/EOBD Code Reader Auto Code Scanner OBD2 [$40.00 USD on amazon].

Any opinions?

As for your "I doubt it should run OK on 87, but let's ignore that as it's not your problem." statement - I was at the dealer a few years ago for a MAJOR issues that required a $12,000+ warranty repair after the fuel float failed and I ran out of gas. There was a factory rep from the UK at the dealer who spoke to me and stated something to the effect that the engine tunes itself to the level of octane and oxygen and that 87 is adequate and that when I ran out, something caused the engine to tune to air? I do know that when the repairs were completed that I thereafter got between 32 and 36 mpg on the highway. I may have misunderstood him, but that is what I believe I recall.

 

I have the same engines as yours and yes, it will run sufficiently knock-free on 87 octane to not affect power or fuel consumption levels. As Jag v8 says, that's a side issue.

It's highly unlikely that you engine is actually knocking or pinging. If so, and assuming that you've not got a stored code for a knock sensor issue, I believe it would be the first time we've seen this.

First suspect is a clogged cat. converter as mentioned. A bad one sounds just like knocking/pinging.

 

2nd time right here lol.


I've had the same issue but couldn't explain it.
I changed the passenger side (under intake) knock sensor awhile ago only after clearing the code about three times. I actually never heard it pinging like it does now. I wouldn't waste my time changing the sensor until you get a code. I am leaning more towards cats.