Ford Focus 1.6 tdci 2008 will not turn over

[Bob777]

Hi

I have a 2008 1.6 tdci econetic, I had the clutch and flywheel changed a few weeks ago, and then five or six days ago the starter would not engage or turn, having rocked the car back and forward the starter then worked. However the problem got worse, to the point were the starter would not work at all, and so I changed it but still the problem persisted. I have checked all the wiring, power is getting to the starter motor and the solenoid when the key is turned, I have even taken the starter motor off and proved it works off the car. I have bump started the car a few times and it runs OK, but I don’t like doing that too often. Anybody any ideas please.

Regards Bob Allen

 

[Tdci-Peter]

48 minutes ago, Bob777 said:

the problem got worse, to the point were the starter would not work at all, and so I changed it but still the problem persisted.

I assume the complete starter & solenoid assembly was changed for a new or reconditioned one. So problems with the starter or solenoid are unlikely, now.

A poor contact in the circuit that energises the solenoid could be the problem: The solenoid needs 20A or so to pull-in, and push the pinion into mesh with the flywheel. This circuit is: battery, starter fuse, starter solenoid in engine bay fuse box, wiring to starter, earth from engine back to battery. Check battery voltage appears at the smaller, solenoid terminal on the motor.

An out of tolerance gear ring on the flywheel might mean it has difficulty engaging.

Poor battery might stop it turning once engaged.

Try monitoring battery voltage while cranking. The interior lighting (if standard filament bulbs) would make a crude indicator. A drop in voltage would mean poor battery, or stalled (jammed) motor. Little drop in voltage would mean bad connection.

Note: The starter solenoid will only fully energise the motor once the pinion has moved into engagement with the flywheel. Prior to this, the low resistance pull-in coil in the solenoid is being energised. Keeping the solenoid in this state (eg jammed pinion) for more than a few seconds, will overheat the solenoid coil. Once the motor is energised, only the higher resistance hold-in coil in the solenoid is used.

 

[Bob777]

Hi

Thanks for the reply, yes new starter and solenoid fitted, I took it off the car when it did not cure the problem and tested it on the bench and it worked fine. I have worked on the car for the last six hours trying to find the fault, having checked the voltage at the battery and at the starter motor, I am getting about 0.2 drop in voltage at all three terminals points on the starter, different from the voltage at the battery. I did charge the battery to about 12.8 before starting work. The battery is only about a year old.

 

Regards Bob

[Tdci-Peter]

1 hour ago, Bob777 said:

I am getting about 0.2 drop in voltage at all three terminals points on the starter,

Hi,

Could you explain that test a bit more, if possible. It sounds a bit like the motor is not pulling much current. That could be a problem with the earth connection from motor to battery, or an internal fault (brushes?) in the motor.

I guess that was when it was trying to crank the engine. Was the starter motor or engine turning at the time? Do you know what the battery voltage was during the test?

If there was 12v across the motor, and it was not turning, the current should have been 100s of Amps, with bigger cable voltage drops than 0.2v, and a severe battery terminal voltage drop. If this huge current was not flowing, then there is a fault.

Check the voltage between the motor casing and the battery -ve terminal. I suspect the fat cable from the engine (usually from a starter bolt) back to the battery is faulty. If it is ok, then there could be a problem with the motor, that did not show on the bench because there was no mechanical load.

Peter.

PS: Note for anyone testing a starter motor on the bench: Make sure the motor is held securely, and use adequate cables, like jump leads. You don't want the motor jumping off onto the floor, or for the wire you are holding to catch fire!

(I am sure Robert knew this, as the bench test was a success!)

[Bob777]

Hi,

Could you explain that test a bit more, if possible. It sounds a bit like the motor is not pulling much current. That could be a problem with the earth connection from motor to battery, or an internal fault (brushes?) in the motor.

Other that the bench test the starter motor has not worked. The earth connection is through the motor casing, there is no cable to earth.

I guess that was when it was trying to crank the engine. Was the starter motor or engine turning at the time? Do you know what the battery voltage was during the test?

At no time has it even tried to crank the engine, and the solenoid has not moved to my knowledge.

If there was 12v across the motor, and it was not turning, the current should have been 100s of Amps, with bigger cable voltage drops than 0.2v, and a severe battery terminal voltage drop. If this huge current was not flowing, then there is a fault.

As you have said there is a fault.

Check the voltage between the motor casing and the battery -ve terminal. I suspect the fat cable from the engine (usually from a starter bolt) back to the battery is faulty. If it is ok, then there could be a problem with the motor, that did not show on the bench because there was no mechanical load.

I will check the voltage on Sunday. There is 12 volts along the fat cable, other than that I have no way of telling if faulty or not.

With the head lights on and trying to start the engine, the lights did not dim.

Regards Bob

[Tdci-Peter]

9 minutes ago, Bob777 said:

.....

I suspect the fat cable from the engine (usually from a starter bolt) back to the battery is faulty

The cable I am concerned about is the one to the battery -ve terminal. There will be a heavy duty cable from battery +ve to the +ve ring connection on the solenoid. But there is also a similar heavy duty cable from the engine to the battery -ve. On my car it is on one of the bell housing bolts, I think it is one that also holds the starter motor in place. This links the starter casing to the battery -ve, and a failure here will give all the symptoms you describe.

Peter.

 

 

[Bob777]

Hi Peter.

Thanks again for your reply.

I never even thought of the earth cable from the engine/gearbox bell housing as being the problem, I was so focused on the starter motor, I think I must have had a senior moment, it’s hard to believe that I used to work on aircraft. The thing is the gearbox was removed to renew the clutch and maybe has not been secured back properly; if I can’t find the offending cable them I will put in one and see if that works. Its 1:30 in morning and I wish I could go out and do it now. I will let you know what the outcome is.

Regards Bob

[Bob777]

Hi Peter.

Many thanks for your help. After all the testing and messing around over the last few days, it was the earth strap after all, I know I should have tried it, but I expect garages to do a professional job when they did the clutch, the one bolt that was loose was the one to the earth strap, the bolts I had to remove to get the starter motor off were very tight. It just never occurred to me that it was the earth. Now to see what the garage is prepared to do about it, having cost me time and money, I think I know the answer to that. I might have to take them to the small claim’s court.

Thanks once again for your help.

Regards Bob

[Tdci-Peter]

26 minutes ago, Bob777 said:

I expect garages to do a professional job

I have never really trusted garages! It all depends on the mechanic doing the job. Some are really good, too many are pretty useless.

It is a shame it cost you so much in time & money. It might be worth pursuing a claim, but just be careful not to let that cause you more additional worry & effort than it is worth!

But really great news to get a fix

Peter.

[Bob777]

Hi Peter.

I hear what you are saying;

I didn’t want a fight as I have mental health issues when it comes to stress. Anyway I had a chat with the garage, and he made me an offer of 50% cost of the starter motor, he was also very apologetic, and said I should have brought it in. I just did not think that it was his problem as I have had work done by him in the past with no problems. The really stupid thing was that the earth strap was very easy to get at, under the air box, the first thing to take off to get to the starter motor, hind-sight is a wonderful thing. Once again thank you for your help.

Regards Bob Allen