I have had my 1998 3.2 xj8 for a little over a month now, and it has been great, always started and got me where I needed, however today, it threw a spanner in the works.

I had been out in the morning to get some shopping, locked the car, and left it for an hour. Came back, unlocked fine, and then went to start, nothing, would not turn over, but everything else seemed to work okay, dashboard lit up normally, heaters, radio, windows all work, and no warning lights or messages.

Thought it may be the immobiliser, so I tried locking the car, and again nothing, just a beep, tried to start and again nothing.

RAC turned up, and tested battery, and said it was in good health, disconnected it, left it for a few minutes, reconnected it, and it fired up straight away, and the central locking was back to working normally.

Spoke to a independant specialist, and he suggested it may a duff battery, but RAC man said his tests were about normal.

Since then I have been out a couple of times in it (with a spanner in the boot just in case), and it has been fine.

So, should i stump up for a new battery on the off chance it may it may be on its way out, or is it likely to a wiring / module issue.

 

I suspect your immobiliser circuit had a hiccup and the standard XJ8 reset worked for you. I would always carry the correct spanner to get a lead off the battery in case you have to do this again. Also, make sure thye key mechanism in the trunk is working and exercise it periodically in case the battery or security modules go bad!

 

I always advocate before jumping to conclusions, take the battery to an auto electrical specialist who has the equipment to 'load test' the battery.
This is the only true way of checking a batteries condition.

Do you have a sealed battery or open cell type?
There's no place for an old style open cell dunger in the boot of a Jaguar!
Do you know how old it is?
Have you checked all the battery connections for cleanliness and security?

As Ross said, always carry a spanner or better still, fit a battery isolator switch
to the negative post of battery.
If you have a multimeter, you can do a standard discharge test yourself to ascertain the batteries health.

Let it stand overnight with all systems off, it should show at least 12.4 volts.
Turn on headlights to full beam and leave for 20 mins.
Followed by another 10 mins with all systems off to allow battery to stabilise.
Now take a voltage reading, if it's below 11.5 the battery is not holding a charge.
personally, I keep my battery on an automatic charger because of it's infrequent use these days and my 100 a/hr VARTA is now 12 years old ;o)

If you do replace your battery, make sure it's a modern sealed cell Calcium battery of at least 100 a/hr capacity and at least 800CCA (Cold Cranking Amps)...anything less with these cars and you're wasting money.
Here's my recomendation for this model.

Products | Autmotive | Silver Dynamic AGM | 605 901 095 | VARTA

I have the earlier version of this.

You may pay a little extra but it's worth it to save the grief and anguish.
I also recomend you buy a decent automatic charger with a de-sulphation
stage in it's specs because this is the biggest killer of high amp batteries that are
subjected to a lot of short run trips and never charged properly.
A few simple guide lines saves a lot of grief ;o)

 

I have a 1998 XJ8 with similar sounding problem. Thought it was immobilizer or some weird parasitic drain. I had a month old battery from VIP and I went to exchange it thinking I got a bad one.

Battery tested fine. I paid for them to check for problem. Ended up being the starter. They found a wiring issue where a wire had been burned. They corrected that with new starter and have not had a problem since.

FYI

 

It's usually down to a problem wih anything that is exposed to the weather...or even where some dozy pillock has been messing around ;o))

 

xjay8,

I like to know the slang expressions of friends in other countries, so I had to look up "dozy pillock." LOL! I'll have to remember that one!

Cheers,

Don

 

Heheeee...don't worry, we have quite a few 'expressions' that could describe that ;o)=)

 

Don...I note that you have a E46 Beemer....you will find a lot of useful tips
on Beemers in general on FCP Euro's web site....unless you have already been there ;o))

 

The battery fitted at the moment is a Bosch S5 silver which I think is 100ah and 830CCa, so should be more than capable, looks quite new, all the terminals are clean and corrosion free, and the voltages are all about right.

Have now put a couple of spanners in the boot just in case, and see how it goes.

Thanks for the advice

 

Before condemning the battery and eagerly looking for expensive solutions ( ), it's worth checking the positive cable (item 2) connection to the High Power Protection Module (item 5)


(click on the image to enlarge it)

Although I can't recall reading of this in relation to the X308, loose or corroded terminals is a regular issue with both the XK8/XKR and X-Type. The X308 is a similar setup so it's a possibility.

Graham

 

In addition to GGG's good suggestion, I would add to check the "false bulkhead" power connectors under the dash near the firewall.

 

Follow the electrical link in my signature for information on all the usual problem areas on these cars.

 

Yes, I get regular emails from FCP Euro as well. In the U.S. other good sources of info and parts include Bavarian Autosport (bavauto.com), Real OEM (realoem.com), Tischer BMW (getbmwparts.com), and a whole host of forums (bimmerforums, bimmerfest, E46Fanatics, etc.).

Cheers,

Don