Odd pump/grumbling noise from engine bay when coming to a stop

[rory_pamphilon]

Hi,


Have had this symptom for a while, no real issues with the car other than this but im curious what may be causing it.

When coming to a stop, can be a gentle or harsh stop, doesnt really matter, i can hear something that sounds a bit like a pump, splutter and then stop. A bit like an engine stalling if it were manual and you stamped on the brakes, except its not the engine obviously. Quite difficult to describe, its not particuarlly loud, coming from front/possibly left hand side of the engine bay. It definately sounds like something that is struggling to keep running as car slows to a stop and the minute the wheels stop this thing chugs and dies.

Things I have checked/changed...

Air con, had this regassed the other day, no issues reported. Old gas was still fine and pump seems fine.
Car serviced recently, oil/filters changed etc, didnt fix the problem.
Tryed running aircon in econ mode for a while, this possibly reduced it a little but i might just have been imagining it.
Very slight leak on radiator, top it up every month or so.

Could it be the secondary air injection pump?


Thanks