Hi Everyone, I have recently been having some issues with my Jaguar, primarily, it turning off randomly. I'm not sure what's causing it, it's almost driving me mad at this point, it'll be fine for a week, and then it'll turn off 5 times in the same day, leaving me stuck in the road until it finally cranks.


Some things I'd like to note:


Alternator is brand new, Battery is brand new, Crank sensor has been replaced recently, I have taken it to the shop a few times, still they do not know what's wrong, everything seems to be good. I can't pull any codes from the car, despite the check engine light being on.


Car will sometimes turn on immediately after turning off, other times it can take a few minutes. Will sometimes jerk a bit and throw up a gearbox fault error without turning off.


If anyone can help me out I'd really really appreciate it, I have no idea what I'm doing here.

 

By turn off you mean total blackout or just the engine but stuff stays lit, does it crank or not at all?
i would start from checking all grounds and that magic line on the ecu box which is well known offender

 

It's never a black out, the car has power, it's just shorting somewhere, sometimes it'll crank right back up no problem, other times it will not crank for a few minutes.

What should I be looking for? Pictures if it isn't asking too much! Thank you for the response.

 

First Get code reader , I suspect the MAF sensor disconnect the MAF and drive the car for while and see if it will turn off as before or not

 

For starters look here, this nut must have to be clean and tight

check all ground points

and get the scanner, you will need it anyway

 

Sounds like oil leakage on one of the cam position sensors or the crankshaft sensor . . . or a loose ground, as noted

 

Another possible cause of your symptoms is an intermittently failing relay. I'd start by checking all the "Ignition Positive" relays and the fuel pump relay. You can find their locations in the Electrical Guide, which you can download here:

Jaguar X308 Electrical Guide 2002

When you test each relay, test it 10 times in succession. Often, an intermittently-failing relay will glitch one of those ten times and reveal itself.

If you find a bad relay, Bosch makes suitable 4- and 5-pin replacements. I can look up part numbers if you find that you need them.

Cheers,

Don

 

Hi, okay, I have some updates. I just tested my relays with a multimeter, all of them were fine, however I noticed I was missing a relay in my fuel pump relay 2 slot, so I slotted in the one from the heated backlight relay, Um, I'm not really sure where to go from here, I had cleaned some of the grounds the ones I could reach, like the two in the front. Don't really know where to go from here, I am considering taking it to a jaguar dealer but I don't wanna get charged for shi I don't need, cause there's a lot wrong with the car however none of it is MAJOR. this is the only issue that makes the car absolutely undriveable.

 

maf sensor possibly? ill try it next

 

An XJ8 (Normally Aspirated does NOT have a secondary fuel pump so NO secondary relay!

 

Oh, on the PDF it says fuel pump relay 1 and 2, i'm not sure.

 

ah never mind, I think I know what you mean. It's supposed to be empty!