removing starter motor, Bora 1.9TD (remove battery and tray)

[DIYspanner]

It has occurred to me that I didn't take the solenoid to bits and look at the contacts - perhaps if dirty, they'd be causing resistance thus reduce current to the starter motor.

 

[Burnerman]

The contacts are sure to be a bit pock marked......I just renew the complete solenoid for around £18.
John

 

[Mursal]

Voltmeter connected across the large solenoid contacts should read zero (less than half a volt) when you are cranking. Only do the test if its to hard to replace and you want to double check.

 

[DIYspanner]

What causes a starter motor to get lazy?

 

[Burnerman]

The main culprits for this is either a worn commutator which causes excess sparking and therefore brush wear or insulation failing on the windings - which if serious will call a halt to the complete motor anyway.
How are you getting on with this?
John

 

[DIYspanner]

Thanks Burnerman

From what you say, I'd go for windings insulation since I cleaned the commutator and brushes when I had the starter motor stripped.


The starter motor is back on the car and somewhat sluggish when cold but it cranks and get the engine started.

 

[Burnerman]

There's a possibility that the starter cables may have some resistance....corrosion and so on. The battery to bodyshell and bodyshell to engine block cables would also have to be perfect.
All these things become cumulative after a while, and of course the battery and alternator output could be slightly down on new.
John

 

[DIYspanner]

An interesting point, corrosion of the the cable end connectors.

I'll check them with an ohmmeter - I assume they should zero.

 

[DIYspanner]

Slow cranking sorted at long last - it was the battery despite an auto-sparky giving it all clear a few weeks ago.

The engine wouldn't crank yesterday so I jump it my Rover 45 TD and it fired up no bother.

Took it to a local shop who tested and confirmed a dropped cell in the battery - bought a 700amp battery there and then and all is well.