which to use, petrol or diesel

[nicholls-a5119]

Noted, Mike , thanks.

[BrianG]

Hi,

18/08 is week eighteen of 2008 so your battery is 13 years old and should be replaced.

[Andy P]

Hi Alan,
Sorry to hear you have other messages.
Hopefully the garage can sort it out easily for you.
From what you have said about the battery it could be the most likely culprit(fingers crossed).
Something you might wish to consider is getting a Bluetooth OBD2 Scanner Code Reader,use it with an App for your phone you can read the codes and reset the engine check light,all from your Android phone.
It only reads the engine codes though.
This is one of the ones that I have:
https://www.ebay.co.uk/sch/i.html?_from ... &_osacat=0
I think you can get them for IOS as well.
I use the Torque Pro App which is only a couple of quid but there is a free one as well.
Just thought I'd mention that because it saves a trip to the garage every time you want to check your codes.
Makes my car life so much easier.
Good luck anyway and stay safe.
Enjoy your car.
Andy

[nicholls-a5119]

Latest update. My XK8 went into my local garage yesterday. A diagnostic check found a spark plug was playing up. All 8 have been replaced and fault codes erased. So, my thoughts are that this was not a problem with cheaper supermarket fuel. I will still regularly use Shell.
Looking forward to hopefully some smooth XK8 driving.

[3.8etypephil]

A little update for you.

After burning off near to half a tank I then topped up with Shell V power. There has been no change. Still running rough with Restricted Performance. In fact, I now have other warnings showing up. They are Stability failure and the ABS light is now on.

I have spoken with my local garage who advise that it is unlikely to be a fuel standard problem. (Although I will use Shell V power when these faults are rectified). So, my XK8 is booked in this week to be analysed and hopefully sorted. I must say that the other faults only started to light after I had checked through all fuses and checked relay connections, All are good and clean. Maybe because I have temporarily disrupted the power supply to that system. The interesting thing I have found is that the battery has a date stamp on the negative terminal of 18/08. Now is this the 18th week of 2008? Or 8th week of 2018? As the tyres were 10 & 11 years old (which I have now changed) I have a sneaky feeling that the battery has not been changed recently and this is a very old battery. I have not known one to last 13 years!
I have heard that these faults can be thrown up when the battery is not healthy.
I will let you know the result of the garage visit.

It's not unusual for modern batteries to last for that length of time; I changed the one on my previous XJ at 12 years, my current XJ at 13 years, and the original is still in our 2013 XF. Just prior to replacement however, both XJs started to display random spurious warning light and fault codes, all of which disappeared when the new batteries were fitted.

Back on topic, Tesco Momentum 99 is, as far as I know, the highest octane petrol generally available in Britain; it does offer measurable economy and performance improvements if one's ECU has been calibrated to take advantage of it, but it's dearer than Satan's fuel.