Yeah....same here schwaggy. Maybe it's just a characteristic of the Jag 4.4...here's to hoping anyway!

 

Yup the lower freq. knocking!

Wow so two others have the same noise? That's slightly reassuring I suppose - I was thinking it was a signature of something about to let loose, but that seems less likely now.

SO the million dollar question is if this is related to my vibration or not?
The vibration does NOT seem to be something that most people would ignore.

Lately, when I start the car cold but not dead cold (like if it's been sitting at work in the sun all day - but for 10 hours) when the engine does its post-start rev to 1300 or so for a second, the vibration is really noticeable. It's pretty much.. *start* *SHAKES w/ post-start rev up* *shaking dies as idle settles* Smooths out a bit as the car warms up.

If I bring up idle to the same 1250 - 1500 point, it's still either missing or out of balance somewhere. So annoying.

 

This is almost the EXACT behavior mine has, except the vibration is worst around 1100 RPM.

Was hoping replacing spark plugs and belts/pulleys would fix it, plan to do that in the next couple months.

 

Whelp I did that, plus a bunch of other stuff - on a 107k mile motor I thought even if it was unrelated it would run better, but nope. Maybe slight MPG gain but zero change with the startup vibration or whatever is causing the balance issue at that lower RPM.

Let me know how it goes as you start to track this down.

 

Got to play with the new scanner at work - I can not view and log all live data parameters for the different modules!

Weirdest things I noticed:

• seemed like high load %. 44% ish when cold and about 36% when warm, at idle.
• Cyl1 advance (only one listed) and timing advance both wanted from 1-15 deg, was always varying. I guess this could be normal
• "torque monitor" was at -50nm?
• Commanded timing between bank 1 and bank 2 was always around 3.5 to 4.0 degrees higher for bank 2.
• Got some short term misfires on the ignition count for cylinder 2 then cylinder 1, but I was lucky to see them before count reset. Never more than 1 count. Like I thought - it's just right on the verge of what it decides is a missfire I guess.
• Accel. pedal (I think D and E positions or something) were at 13.3% at idle with no contact? TPS at 12.16% at idle.

Maybe someone can tell me if these are normal? I might be able to get another LR3 that I can plug into and compare.

 

I have a scanner (iphone app) which I think should give me all the same values. I'll check it out and report back how mine compared. They look relatively normal at first glance.