2007 Jaguar XJ8 VDP 39K won't re-start after driving with engine at normal operating temperature. Won't even turn over all instrument lights work headlights work but no attempt to turn over. Instrument panel shows Cruise Not Available, Transmission Fault, Parking Brake Fault. After sitting 20/30 minutes starts and runs perfect and all Fault signs go away. Could this be a battery problem with low voltage or something someone is familiar with?

Thanks,

W. Jones Georgia, USA

 

You've posted in the wrong forum for your car. This one is for the XJ from 2009. Get your post moved to the X350/X358 forum in the Modern Jaguars forum group; you'll likely get a quick response.

 

How old is the battery also if you hook up a jump battery will it start

 

Yes, tried jumper cables to no avail. Battery is only 18 month's old and checks out ok.

 

Have you checked earth points

 

Not familiar with doing that can you advise the procedure to check earth points?

 

The main one is in the boot check for any corrosion if so remove the lead and clean , the faults you are getting is very similar to a flat battery but you must start with the basics

 

No corrosion everything looks new and shiny. Using Interstate battery 18 month's old it was checked out and showed fully charged but voltage was low. I live near the Interstate battery distributor they kept the battery 3 days and said it was fine but I am wondering if the voltage varies could that be the problem.

 

Battery cables can "die" with corrosion buildup in the crimped ends. I'd check the cable with a volt meter to see if they pass current.

 

2005 XJ8-L ~ 90K to present 97K miles has been showing similar short off-time on hot day signs, save that it cranks the engine really well, just dasn't fire.

No issues if it has been left to sit for 30 minutes or so. Battery is fine (I have meters and very good primary and 'sustainer' chargers to-hand). Earths are good.

Update: In my case, no fault displays, nor any stored codes durign the several times that I had a reader already attached.

At first I suspected vapour-lock, as my '72 BMW six had.

More inclined after watching it for a year to suspect a switch or sensor or alleged-computationally-capable object is sensitive to heat build-up.

My 'fix' is to remove the key from the ignition, count to ten, try again.

Now and then I have to do that twice, rarely three times. Mebbe once a year it is persistent enough I open the bonnet, open all windows and sunroof, go have a smoke, try again in five minutes. Seems to always respond to that.

Nary an issue in cooler weather.

So far...

I'll be tracking responses to your more crippling issue with serious interest!

 

First off, could you get the duplicate thread deleted that I just replied to !!

Then.....

I haven't seen a problem like this where it seems heat is affecting the starter circuit. However as you have fault displays you need to do something about them as the clue to your problem may lie there. Whilst you say the faults "go away", they generate a code which is then stored. So first off, get the stored fault codes read and interpreted. If the system thinks your transmission or something is not correct, it will not allow the engine to be started, for instance it must not be in gear. There is also an interlock with the footbrake too.

 

I had the same faults come up on my dash when The battery went flat so you will have to get the car hot and turn the car off at home and start checking where you have a bad connection try the major power leads first that go to the starter and fuse box it can only be a bad connection did you have any work done on the car prior to this fault

 

No work done prior to this problem. Actually, was on my way to a local Jag repair shop to get it checked out for running hot in slow traffic. It had approached the red line a couple of times during the week before. On the way to the shop I stopped for a few minutes to renew my license tag and that's when it would not turn over until I waited about 20 minutes and then it started easily. Thermostat housing had to be replaced for the overheating problem. After leaving the shop stopped on the way home for 30 minutes and it failed to turn over again then turned over and started as before after about 20 minutes. Next day drove it on 2 errands about 15 miles left it running at each stop about 10 minutes each returned home shut it off and checked it 5 times every few minutes and it turned over and started immediately every time. Bringing it to the Jaguar dealer service on Monday and hoping it will not start when I get there otherwise it may be difficult to see what the problem is.

 

Fault codes are stored for handling the very situation you have, intermittent faults.

 

Brought the 2007 XJ8 VDP to the Jaguar dealer in Atlanta they kept it 4 days and came up with nothing as to why the car won't turn over when hot. Battery is only 18 month's old and checked perfect. After considering everything I decide to buy a new battery just in case there was a problem when the battery got hot. Drove the car home shut it off waited 15 minutes and the same thing it won't turn over. Surely this Jag is not the only one that has done this someone must have the answer. Also, the old battery and the new battery is an Interstate. The Jag dealer uses only Interstate batteries. The old battery had a vent but the new battery does not have a vent is this ok? Does Jaguar have a battery of their own as does BMW and Mercedes surely new Jag's don't come with other brand batteries?

Thanks for any help the Jag has only 39600 miles and is not drivable not knowing if you can get back home. Also, as mentioned in previous post when the car won't turn over the instrument panel has Cruise Not Available, Transmission Fault and Parking Brake Fault. By raising the hood and letting the engine cool off for a while the car turns over and starts immediately and runs perfectly until it's shut off then it does the same thing over again won't turn over.

 

Did the problem occur when the jag dealer had it for the four days . The symptoms you describe are very similar to a flat battery. If you leave the bonnet down does it take longer before it will start

 

They said it did it only once when I first brought it in. I spoke to them at least twice each day by phone and told them they had to drive the car to get the engine hot before it would duplicate the problem. They said they did a couple of times but it started with no problem after 15 minutes. I wonder if they really tried because I can get it to do it every time even with the new battery and yes it takes longer to start with the bonnet down which pretty much proves its engine heat related. On the battery vent issue I happen to live only 15 minutes from the Interstate battery distributor. I went today and they said the new battery should be vented it had a vent on each end of the battery and depending on how the battery fits in the car one vent should be plugged up with their special plug and the vent tube installed on the other vent. They took care of it immediately and stated not likely but could cause a problem if not vented. One would think the Jaguar service dealer would have known to do that. Anyhow, battery problem solved but starting (turning over) with the engine hot is still a problem.

 

First place to look is to see if the starter is getting a signal from the ignition switch this way you can tell if it's the battery cables or the ignition side also check the earth wire from the engine not sure where the earth cable is on the engine but I'm sure someone will know unless you know a auto electrician it's a process of finding where the bad connection or faulty component is

 

Heads UP!

Sumthin' interesting just turned up in another thread, same problems:

https://www.jaguarforums.com/forum/x...1/#post1276726

Apparently, crippling heat build-up dasn't have to be in the 'obvious' place.. underhood (OK ...'under bonnet')

Biologicals side of the firewall houses a scad of 'tronics, too.

I'll start with trying the sunscreen and/or airing-out the cabin, even running the AC fan off battery for a few minutes before keying-up a start.

More when I know more.

 

If this is the problem try taking the car for a drive then leave it parked with the windows open see if the car starts