Restricted performance mode

[Jag190902]

Hi

I have a really frustrating fault that's suddenly appeared on my 2000 XK8 (normally aspirated), It's been laid up for approx. 9 months and has been connected to a battery conditioner the whole time. I recently had the gearbox overhauled and the car started and drove well at first though went into restricted performance mode and this won't clear now when running. If I switch off and wait a couple of minutes, it will start and run normally for about 20-30 secs then goes into restricted mode. I read the codes using a code reader and got the following messages: P0303 cylinder3 misfire, P1316 misfire rate excess emissions, P0353 Ignition coil C primary/secondary circuit malfunction, P1642 CAN link circuit malfunction, P1646 heated oxygen sensor bank1 open/shorted. The battery on the car is 3 1/2 yrs old and the only other work that has been done recently was to replace the top tensioners over the winter though the car started and ran beautifully once this was done (it had started with the death rattle). Any help would be greatly appreciated as it'd got me flummoxed as to where to start.

[Andy P]

Hi Jag190902,
Your codes indicate a faulty coil-pack on the third cylinder back from the radiator on the drivers side(If you have a RHD vehicle).

Cylinder Numbering

The letter's in the chart refer to the coil packs.
Once you've changed the coil pack you might find the P1316 code will go.
Not sure if the other two will follow suit but if your lucky they will go as well.
Good luck
Hope that helps.
Andy

[Jag190902]

Thanks Andy. I've replaced the coil pack on N0.3 as suggested and the car runs beautifully again. I cleared the codes using my reader and none have re-appeared. I think it may be prudent to change the others also as if 1 has gone down suddenly the others can't be far off (113K on the clock). I've priced them up at British car parts and it works out at £190 for the other 7 vs. £538 from Jaguar. What are the thoughts on the aftermarket alternatives compared to genuine Jaguar?

[Andy P]

Hi Jag190902,
Now there's a question,some always go with Jaguar only parts while others refuse to pay the higher price and go with aftermarket.
Myself I go for good pre-owned original equipment,for example I had a coil pack go on me back in March and when I went to change it found two had been changed before with after market ones(although they were not the faulty one's),looked around on e-Bay and picked up two from one seller for £16 and another two from a different seller for £14 all genuine Denso parts with correct part numbers,so that's four coil packs for £30,used one for the replacement and have three spare ones .All genuine ones in the car .
It not difficult to tell if a seller is genuine,both of these chaps had Jags that had suffered from bad corrosion as so often happens but the engines and auxiliary parts are fine.
Anyway since I changed the coil pack I have been to the Blenheim Festival and then spent a week driving around the Cotswold's totalling about 1000 miles before we got back home with no problems .
I suppose the choice is yours in the end but I like hang on to my money for as long as possible(every pounds a prisoner ) .
Glad your all sorted now anyway.
Enjoy your cars.
Andy