Intermittent cranking problem

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Hi everyone, I have been a JEC member for nearly two years now but this is my first attempt at posting a query so please bear with me. I am lucky enough to own two Jaguars, the first a 2004 XKR convertible in Slate Grey metallic with ivory interior and 41,000 recorded miles. This is currently in storage for the winter. Then, in January of this year I bought a one owner 2009 XJ 2.7 TDVI Sovereign with 44,000 recorded miles in Pearl Grey metallic and ivory interior and FMDSH. I have since discovered that the car had a brand new Jaguar engine, fitted at a Jaguar main dealer at 42,000 miles. I love the car but ownership has not been without its tribulations and my experiences have basically been a tale of two dealerships who were poles apart in customer focus. Some day I will take the time to commit this story to print as it does make interesting reading and unfortunately highlights totally different standards offered to customers within the extended Jaguar family. Anyway I digress, my problem is that for the last few months occasionally the XJ cranks over very "lazily" indeed and only just fires. I experienced the worst yesterday afternoon. When trying to start it, it struggled to turn over for about four turns. I switched the ignition off and tried again and once again it struggled to turn over to such an extent that I thought the battery was in imminent danger of dying altogether and I was going to be stuck. However, it fired on about the fourth turn. This was immediately after I had just returned from a fast motorway run of approximately 25 miles. The weather at the time was sunny and quite warm. The next morning I went to work on my motorbike leaving the car for my wife. I feared the worst as, when I left, the car was covered in frost. I immediately thought this would kill the battery altogether and the car would be stuck on the drive. I rang my wife later expecting to hear some bad news but I was quite surprised when she told me it had started first time with no trouble whatsoever, and had also done so on a number of occasions since then. As I said this has happened occasionally and I am now constantly worried that one day it will not start at all leaving me stranded. The majority of times the battery kicks it over no problem at all and it fires first turn but then, inexplicably and for no apparent reason, the above happens.
Has anybody experienced any similar circumstances and if so could you please tell me the reason, and more importantly the cure.
Thanks in anticipation.

[J44EAG]

This sounds very much like a case of Winter Battery Syndrome. Indeed, only today and for not the first time, my sisters 08 plate Fiesta failed to start. Her husband said he had fitted a new battery.....had he heck!

As another car was parked in front of the Fiesta, it was impossible to back up my X350 for a jump start. Having been called out, my volt meter showed just 11.83 volts. Way below what is required to fire the electronic "gates" in the power train ecu. Electronic gates need at least 12 volts to perform satisfactorally. As winter temperatures drop, so does voltage. 12 volts is a well discharged battery, 12.4 is partially discharged. Ideally you are looking for a battery terminal voltage of 12.8v and above.

With the Fiesta, I finally persuaded my sister to stump up for a Varta Blue Premium battery with 5 year warrenty from the RAC man. Connected up, the car cranked and fired on the first turn of the key. The end of a problem at least for the next five years. The moral of the story is that if the battery is old and you are experiencing starting failures, throw out the old battery and fit a premium new Bosch Silver or Varta Blue battery. Avoid the cheap and very nasty economy batteries. They are just not up to running the systems on these electronically sensitive cars.

Look at the battery in the boot and grab its number. Probably 091. Note the positive and negative terminal orientation. Go to ebay and select a Bosch or Varta from the many sellers there. Aim to pay about £98 delivered for one of these 90ah batteries. Occasionally you can find them with 100ah capacity in the same size case. Always nice to have a bit of extra storeage capacity or grunt.

To confirm you need a new battery, have a load drop test performed by a local garage. That simulates starting load and you can watch terminal voltage collapse under load. This type of test confirms the condition of the battery one way or another. If in doubt, chuck it out.

Mike K

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Thanks for that Mike. Have used the car tonight and it started first time without a problem but, to test your inference, I will do as you suggest at the weekend and have the battery tested. Thanks for the advice and tips on purchasing a new battery if necessary.
Regards, Reg Page

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Hi Mike, just to give you an update, heeded your advice and took the car to my local garage. Although not a Jaguar specialist the owner does actually own a Jaguar. He tested the battery twice and on both occasions it registered 110%, so definitely not the battery. It is in fact a Varta, liveried as an RAC battery, so obviously a replacement and looks almost new. All the terminals appeared secure and again in excellent condition. The technician stated it would be extremely hard to diagnose an intermittent fault so advised using the car until it failed then they could do something. Not really the result I wanted but, in reality, he could have worked on it for days, building up a big bill, with no guaranteed result. I am going to buy one of those Jumping Jacks, just to keep in the car, in case it ever refuses to start !!! Thanks for the advice and at least I now have some sort of plan in place if the worst comes to the worst.

Regards,

Reg

[andypryce]

Agree definitely worth investing in one of the compact emergency starters, you can get a good one for around £50, at least you have that safety net then, which will give you more confidence. Does sound like a dying battery though...

[J44EAG]

Reg,

Lift the boot floor and look at the ground lead connection points along the OS side chassis legs just below the lifting boot floor. Slacken the nuts and pull the black ground cables off the threaded studs. Clean up studs and cable connections with abrasive paper or perhaps a small brass or ali brush. Don`t use a steel brush under any circumstances. Wipe off corrosive dust if present. Apply a smear of Vasaline and reassemble. Also check battery terminals for similar corrosion. Try that and see if there is any improvement.

Mike K

[ptjs1]

Reg,

+1 for Mikes' suggestion. My first thought reading your post was that the problem would lie in either the earth circuit of the car or the connections of the starter motor. That type of intermittent cranking problem is often in the connections rather than the battery per se. Any minor connection corrosion and it just can't pull the amps when cranking although the voltage can register to the ecu as sufficient to allow the cranking process. I can't remember on the x350 if the starter positive feed is coming off one of the bulkhead terminals?

I would start by checking voltages direct at the battery terminals. Then check again between the positive battery terminal and the first earth stud (rather than the battery -ve). Then check again at any and all of the bulkhead points, including checking battery +ve to bulkhead earth, and battery -ve to bulkhead +ve. (Yes, you'll need some long leads!) Compare the readings. You might then start to pin down where is the problem.

Good luck

Paul

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Hi Mike, Paul and Andy,
Thank you all for taking the time to reply. Mike and Paul, I will work through your suggestions over the weekend to see if it has any effect on the cranking issue and report back in due course, although I have a nasty gut feeling that this is going to be a long running problem.

Thanks again All and Regards,
Reg