Starter "flat spot" - what's causing this?

[Huw Powell]

> For quite a few months now, my 1988 90Q has suffered from this intermittent
> problem.  Sometimes the car starts like a champ, other times you turn the
> key and ... silence.   There is power draw (voltage drops) but nothing
> moves, clicks or otherwise.  Total silence.  Push start.

If it's truly silent but you get a power draw, it's almost certainly the 
starter.  In the meantime, the old trick is to whack it lightly with a 
hammer to see if it will work on the next try.

> As a note, I found one way of dealing with the issue:
> When the starter wouldn't work, I put the car into second gear and rock it,
> trying to get the engine to rotate forward.  After such treatment it would
> often start. 

That might have had the "hammer" effect - or, if you don't get true 
silence but a click and whirring sound, you could be missing a few 
flywheel teeth, as suggested.

> However, a strange, grinding noise persists for a few seconds
> after the engine has started and then something disengages, everything
> returns to normal.

That could be the starter solenoid thing sticking and keeping on the 
flywheel after you release the key.

Prior to replacing the starter, I would use a test light on the starter 
trigger wire to make sure it's not the ignition switch at fault.

-- 
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/