Greeting,

I have just picked up (about a month ago) a 2000 XK8 convertible with 65 k miles. For the first 2 weeks it was a dream to drive, everything worked great.

Since then, my check engine light has come on and it runs rough with the "Restricted Performance" illuminated. I put a scanner on it and it said I have a miss fire in cylinder two. Since I just got it i figured I would change all the coil packs and plugs since this happened with my BMW 740 Li. Did all the work with no results.

Any Ideas or suggestions would be greatly appreciated!!!

I have a 2000 XK8 with 115K on it so I have seen a lot. First these cars are sesitive to voltage so check your battery and alternator.
Second on this forum you can download a copy of the Workshop Manual and with your OBD codes the manual will take you step by step to diagnose the problem for the specific code.
Good luck.

Awesome!, thank you for the quick reply!!

What about the plugs? Condition, age, mileage?

I put in new coil packs and new platinum plugs, it's a 2000 with 65000 miles, got it from an estate sale with tons of receipts and records of maintenance, big reason why I'm baffled

I suggest you post the actual code you are getting in case you are looking at the wrong definition.

Duh, You did say that in your message. Plug wires? Hmmmmm.

Try cleaning your MAF sensor, I had the same problem, cleaned the MAF sensor with proper cleaner and not had a problem since.

Yes! The DTC you are seeing would help a lot.

I'm starting to think making (fairly major) changes to these unsupecting cars can cause them to have a tizzy. What kind of coil packs did you use...? And please tell me you saved the old (original) ones....? And plugs and gap (double check plug gap out of the box)...

With a lot of bumps on the head I'm learning (kinda) that these cars don't like hard changes like new looms to the ignition system, new coil packs, plugs etc - because something was going wrong with the originals - and a bunch of new parts get thrown.

After swapping everything. Did you try a hard reset of the cars systems? Might help. I do hard resets by disconnecting the battery, clipping the 2 leads together, then switching the key to the run position and leaving it for a long while. Then, returning the key to OFF, reconnecting the battery and trying again. I'll first clear ALL codes on first start,,, then see what happens.

More than likely, you have a sticking injector. Get some Chevron Techron fuel system cleaner additive and run a tank through. If this doesn't fix it, replace the #2 injector.

How often does additive quickly solve the problem? Occasional use to prevent problems makes sense.

First off, I have to admit I’m down with the OCD crowd, as long as the behavior doesn’t hurt anyone else.


That said, I use a 20 oz bottle of Techron Full fuel system cleaner every 3rd tank of gas , which is about 1 every 1,000 miles. I have a 2002 4.0 XKR, with 177,000 miles on it and the injectors have never been serviced . The supercharger has to come off to do the job and I just want to put that off as long as possible.

Using that much Techron does not seem to have had any negative consequences (besides the cost), since I’ve been doing it for 3.5 years.

I also have other OCD XKR behaviors, like keeping the car on a battery tender whenever it’s not being driven overnight or longer.


Plus the OCD of opening the hood (bonnet) when the car in back in the garage after a hot drive. Heat soak will shorten the life of the cooling hoses (some of which are also under the supercharger) and mine have never been changed. Would like them to last another 5 years at least.

My car is a daily driver with about 15,000-20,000 miles logged every year. So far it’s been more dependable than any other 20 year old car I’ve owned.

Z

Opening the bonnet (hood) a clever idea (unless you're driving of course). Maybe plug in a fan nearby. We're looking at 100+ temps all next week. For those of us us that don't have AC garages, post drive cooling suggests are helpful.

You have me pegged re the fan usage. The less time those hoses are hot, the better. My 20” floor fan fits nicely atop the radiator support and cools the hoses and / or motor down much faster.

Z

So far, the 06 lives in a fairly cool storage shed. No 110 for a fan (I wish) but am going to open the hood. I can see how you've gotten the big numbers on the speedo. Changing fluids regularly another key to those miles.

My cat has been healed! Thank you to all who offered advice, all of which was good. Turns out to be a bad injector on cylinder 2. Replaced that and she runs perfect!! Thanks again.