About two weeks ago I got in the Jag and started her up, well tried to start her. Usually this is a two second process once the key is turned in the ignition. There is a slight whirring noise and the engine catches. At which point I release the key. This time however she hadn't started, so I turned the key again and all I got was a whirring sound. This is of course as far as I can tell the starter motor turning, but it doesn't sound like its engaging with anything. I tried several times with the same result. then nothing. not even a click from the start relay.
At that point I had to leave her sitting and take an alternate vehicle. Tried to start her again the next day with absolutely nothing happening. I then pulled the battery and placed it on charge until the the unit gave me a green light. I disconnected the battery from charge, but it sat for about five hours before I could get it back in the car. Once the battery was reinstalled in the car I tried to start the her and got the whirring noise again for a couple of tries then again nothing. At this point I checked the voltage on the battery and it was about 9.4volts.

So now I'm not sure if I have a stripped Bendix, flywheel/flex plate or a bad battery. I put the issue aside and went on with life for a couple of weeks until a couple of days ago when I had time to delve further. I once again charged the battery overnite. The voltage checked at 13.94volts in the morning so I let the battery sit for several hours and checked it again. It had dropped to 12.54 volts. So I left it overnite and checked in the morning, at which point it still showed 12.54 volts. I placed the battery back on charge for about six hours bringing it back up to 13.90 volts and immediately refitted it back in the car. I then check the voltage one more time 13.57 volts.
Once again all I get is a whirring sound, and so disheartened I think we are looking at some major work to get this sorted. Knowing that the battery has a good charge and feeling like I had nothing to lose I decided to keep the ignition engaged for a long period (maybe 6 to 8 seconds) at the third attempt I thought I felt a slight cough from the engine, so I continued with longer starting attempts. The engine made several small attempts to start which meant I kept trying for longer and longer startups, until she finally coughed into life. It would seem that what sounded to me like a stripped Bendix is the usual sound from one of these engines turning but not starting. So having got her running I let her idle for a while and check the battery voltage and its at 13.92 at idle. I shut off the engine and do a restart, and she fires up immediately. I do this five or six times more and she fires with no hesitation.

It's now five hours later and she just started up on the button. I am now concerned this fault will return when I'm away from the house and at this point have no idea what it is or what was causing it. If anyone has any ideas please let me know.

Cheers Steve.

 

Steve:
It is hard to make a complete connection between cause and effect with your description of the problem, but if it happens again, you should find the differential diagnosis of whether it is the Bendix. That would be, "During the "whirring" sound, does the engine turn?" You would figure that out by having someone look at the front of the engine and see if the belts are moving!

Other than the original low voltage, your battery voltages seem right. I suspect you are dealing with a failing battery, maybe some "cylinder wash" (look it up), and possibly just a normal engine flood. These cars, at least the 4.0 version are known to do that after a short run, like if you are moving the car into the garage.

 

cheers Sparkandzap, After getting the car started I think the whirring sound is normal even when the bendix is engaging. It's just so different from the err err sound a vehicle usually makes when trying to start, but if this fault occurs again I will have someone observe the belts as I crank the engine. I checked into cylinder wash, which is basically flooding an I would have thought a week was long enough for the cylinders to dry out if that was the issue. On second thoughts it probably would have not made any difference without removing the plugs during that time. I am as you pointed out considering a failing battery, but your suggestion of cylinder wash seems quite possible. We shall see if it starts tomorrow after a cold damp British night. Many thanks for your reply.


Steve