RE: Fuel Pump

["Buchholz, Steven" <Steven.Buchholz@kla-tencor.com>]

>     My experience with Audi fuel pumps is that they last about 100,000 kms
> (roughly 60,000 miles) before they get really noisy. Having said that, I
> have never driven one to failure but have replaced them when they have
> started to make the loud warbling noise you mentioned. There may have been
> more life in them, but I'm not too anxious to be left sitting at the side
> of
> the road at -40 F wishing I had changed that dang pump.
>     I was talking to a Bosch rep who said the pumps were rated for 6000
> hours. I figure I've been getting 1500 hours out of mine.
> 
IME the only car I've had to do the pump on is the Fox ... so far the QTC,
'88 5kCSQA and the rest are running on either the original or pumps replaced
by POs ...

The pump in the 5k does make a reasonable bit of noise and more than one
person has told me that it is about to go ... but then it has been about the
same as long as I've owned the car.  I'm going to replace it as part of the
complete rebuild that is now in process, so I guess I won't know how long
they last either ... :-)

The thing about the Bosch hour rating is that it is problably under ideal
conditions pure fluid and a specified delivvery and backpressure situation
... in the car the pump is passing whatever kidney stones happen to come its
way and will have to work harder as the fuel filter gets more clogged ... so
I can't say I'd even expect them to last 6000 hours ... I guess I'd be happy
with 3000-4000 myself ... perhaps I'll start keeping track now ... :)

Steve Buchholz
San Jose, CA (USA)