Stuart,

That was my thought - a bad water pump would be of insignificant load on the idle of the engine .... now I need to figure out what else occurred while the pump was replaced.   

Maybe the Hyena was merely happy to have some overdue attention and the purring will be short lived ;-)

On 27-Aug-2015, at 22:25, Stuart MacMillan wrote:

> Roy,
> 
> The load on the water pump is constant at idle. It just pushes coolant
> around, so the load only varies with rpms, and it's not much. A/C has a
> variable on/off load at idle, but there are compensating rpm gizmos for
> that.  Irregular idle can have many sources, especially with the Digifant
> system.
> 
> Stuart
>