First 7 days have come to an end and so far I am thoroughly enjoying my new Jag. Couple quick questions and thanks in advance for the answers:

1. When at idle, either while sitting at a red light with my foot on the brake or sitting in my driveway while the gear is in park, I feel a small shake throughout the car. It's not too bad but it's definitely there. My first instinct is that because of the large v-8 engine and 510 horsepower, that's just a rumble to remind me of the power. But I'm coming from a Benz CLS which wasn't a slow car by any means and also had a V8 and I never felt a "shake" quite like this. Is this something I need be worried about? Should I bring it to the dealer? Or is this normal?

2. While the leather seats feel great for the most part, the side bolstering around my thighs is a little uncomfortable. I've played with all the seat adjustments but I can't seem to find anything that basically lowers or flatens out the seat so that it doesn't pinch the outside of my legs. Yeah I could drop a few lbs and that might work but there's got to be an easier way.

3. Lastly, is there a digital speedometer reading available or is it just the gauges that are available? Can't seem to find out the answer to this.

That's it for now, although I'm sure there will be more questions to come.

 

1.). My car is the same way. I mentioned this to my Jaguar tech, and he said its completely normal. I'd bet that a good aftermarket tune could get rid of it, but I wouldn't worry.

2.). Again, completely normal. I feel the same way about my car. I'd love get it more comfortable, but then I remember that I bought the XFR for a reason... Superb performance. The sets are like that for a reason, that being superior grip for the driver on the track. It's a compromise for daily driving, but I just considerit a quirk of a superb performance automobile.

3.) No digital speedo as far as I know. Why would you need it?

 

Not sure what year you have but in the '12 cars if you hit the button on the trip computer/lighting/turn signal stalk it will cycle through the centre LCD between the gauges, one of the modes displays a digital speedo, I usually keep mine in this mode, very helpful.

 

My 09 S/C and my 10 XFR has this same shake or stumble. It feels like a boxter engine would. Almost as if the idle is to low. I also have a E63 AMG and that big block does not have this stumble. But my idle is also a hair higher than my XFR is.
When at idle and when you shut the car off the Jag sounds like a loose clunky motor but since they all sound like this I bet it is normal. I read somehwere that the XFR motors are hand built, is this true? I know my AMG is handbuilt but I had no clue the 5.0L Jag motors where too. Anyone know what exact model # the blower is on the 5.0L? Eaton 112M?

 

Interesting, my 09 S/C doesn't have any shake of stumble at idle. I pick up a new 2012 S/C tomorrow and will see if it has the problem.

 

Wonder if the SC cars have a different cam that the NA cars....I idle smooth like butter in my NA 5.0

Any techs on here that can confirm my hunch?

 

Thanks for the responses. So it sounds like I'll have to just live with the "shake" and the seats. Not a real big deal. I still love the car. As far as why would I need the digital speedometer, I don't know, I guess just for convenience. Of course my wife asks why I need a 510 hp car or why I need to golf twice a week or why I love ****. I don't have answers for these things either but the heart wants what the heart wants! Just teasing about the **** (maybe).

Anyway, my car is a 2010 and I did press the signal stalk and while it does change the readout to a view different options, digital speedometer wasn't one of them. Oh well. Thanks again for the help, and I hope everyone enjoys their cars as much as I do.

 

I have the same cpmplaint about the outside seat bolster on my thigh and I find myself angling in slightly toward the centre of the car for the correct position.

My 2011 XFR is smooth as when idling. Must be the BP Ultimate we have in NZ

SugarChev check the thread out on Ultragauge. Simple to install and you get all kinds of digital readouts. I find the speedo to be 4-5 kph out but the Ultragauge is bang on.

 

All cross crank V8 engines (like most and including the Jaguar engine) suffer from firing order induced imbalance causing a characteristic shake noticeable at idle. The firing order causes the engine to rock gently from one rear corner across diagonally to the opposite front corner. Flat plane crank V8 engines do not suffer from this but do share an imbalance characteristic with inline four cylinder engines as these are essentially two in line fours sharing a common crank.

Incidentally, this firing order issue also means it is not feasible to optimize exhaust headers for cross crank V8, the Ford GT40 racing engine is a good example of how complex the headers have to be to achieve this, also the intake stacks have to be different lengths.

Getting rid of this shake involves a compromise in engine mounts. Spend enough money on mounts and this can be reduced but never eliminated. Jaguar is known for spending their money wisely!



Incidentally

 

Also, worth mentioning the to the dealer to check TSB JTB00244NAS1 - Off Throttle Engine Idle Fuel Cut In Timing....sounds like your symptoms fit it.

 

I found them very intrusive when I considered purchasing one last year, and wouldn't be surprised to see a factory change. Not an ideal application of support for spirited driving on or off the track. I suppose if it was bothersome enough one could have an auto seat upholsterer try to modify it.

Bruce

 

Same here. Rock solid at idle in my 09 S/C.

 

I find them to be fine. I generally like a figure hugging seat though. The XFR seat is way more forgiving and comfortable than sports seats from other manufacturers - try a C63 or a Porsche 911! The standard (pre 2012) seats are just pathetic when it comes to staying put through corners - if I could have had the sports seats in a SC I think I would have saved my money and not bought an XFR.

 

Jaguar supercharger implementation history:
They used the M90 on the 6cyl supercharged(1995-1997 XJR) M112 on the 4.0 and 4.2 8 Cylinder engines. All the 5.0 supercharged have the new style eaton TVS series, a 2300 model on the XFR I believe

 

Me too...have you tried the ones in the XKR? I had mine on a 20 corner track within 24 hours of taking delivery and they held me in place quite well, especially compared to some other cars.

 

Well, I just put the first 80 miles of combined city/highway driving on a new 2012 S/C and, like my 2009 S/C, there was no detectable shaking or stumbling at idle. What is present at idle (that was not in my 09 S/C) is a notable exhaust rumbling sound inside the vehicle. It was tough to tell if the engine was running on the 2009 at idle, but that's not the case with this 2012 S/C. Additionally, the rumbling frequency coinsides with the engine revs and increases in sound level several fold with normal acceleration through the 2nd and 3rd gears and then fades away at crusing speeds.