no start issue. strange to me

[ATMDC]

ok my friend has a 2001 4.6 v8 expedition. well he was driving home one day and it just cut off. so he tried to start it and all it would do was click.

i took a look at it and watched him try to start it and all it would do is click real loud from the starter and i could see the pulleys move a tad bit each time he did it. it seems as if the starter is connecting with the engine but just not turning it.

i checked the oil it was fine, there were no codes. we were thinking the starter, but surely this wouldnt cause it to cut off in the middle of driving though right?

thanks for the help.

[Selectron]

If it cut off whilst driving and then failed to crank, then I'd be looking first at the charging system - is the alternator belt still in position and if so does it still have reasonable tension? If that appears normal then I'd check the battery voltage, which should be around 12.6V with the vehicle at rest - 'at rest' meaning with the ignition switched off and with no attempts at cranking during the previous fifteen minutes or so.

The difference between a fully-charged battery and a flat battery is very little in terms of voltage - you can use these figures as a rough guide:

12.6V 100% charge
12.4V 75% charge
12.2V 50% charge
12.0V 25% charge
11.9V battery discharged

So if you find the battery is down around the 12V mark then you don't have a hope of cranking the engine until the battery is recharged, and then you would need to start looking for a fault in the charging system which caused the flat battery in the first place. If you don't have a voltmeter then switch the headlights on, using high beam or low beam - they should still be shining brightly after thirty seconds or so, but if they very quickly dim then the battery is flat.

If the battery voltage is good, then you should remove the battery connectors and clean the terminals and the mating surfaces of the connectors, using a wire brush. Preferably smear them with a protective coating of petroleum jelly (Vaseline) or dielectric grease prior to reassembly, to inhibit future corrosion.

There will be a heavy duty ground lead running from battery negative terminal to engine, where it will bolt onto the engine block, and that should be inspected and cleaned too. Same thing if you have another fairly heavy ground lead which bolts to the firewall.

Connections from battery to alternator should be checked, and also connections from battery to starter, although I'm not sure how your starter is configured so I don't know if a problem there could have caused it to cut out whilst driving, but it wouldn't do any harm to check anyway. You'd be looking for loose or corroded connectors, and also inspect the wires to see if there has been any water ingress beneath the insulation, leading to internal corrosion. Do that by looking closely at the end of the wires, where the connector attaches.

If you have access to a voltmeter, then the terminal voltage of the battery will be the best clue to what the problem is - if it's low then check the charging system, and if it's normal then look for bad wiring and bad connections.

[ATMDC]

thanks for the help i checked everything with a volt meter, battery and alternator were good. i took the starter out and had it tested. it was good. so i dunno know, reams seems like the engine locked up. i wasnt able to turn the crank with a breaker bar.

[Johnny Mullet]

Motor is locked up if the breaker-bar diagnosis was done. That sux.

[rhandwor]

I agree with Johnny did he happen to loose oil pressure when this happened?