[Vwdiesel] Symptoms of a clogged fuel filter

[Val Christian]

> In a message dated 12/27/2006 9:51:05 AM Pacific Standard Time, 
> ub3ratl4sf00 at gmail.com writes:
> 
> > My cars performance has been dragging lately, mostly on light-medium
> > hillside or slopes. I suspect the fuel filter is clogged up, but perhaps
> > someone can tell me what the signs of that are
> > 
> 
>   My experience has been that rarely (never?) has it been a fuel 
> filter.  Air leaks from deteriorating fuel lines, leaking connections, 
> dirty air filter and plugging fuel filter can all lead to similar conditions 
> as far as a loss of power indicated by the "seat of the pants" dyno.
>      Loren

Agreed.  I run fuel filters generally until I have a known problem,
or when I notice that there is a stumbing of the engine, under full 
power when the car is cold in the morning (getting on the expressway,
climbing a grade at WOT tends to reveal flow problems).  [And normally
this is seen on COLD mornings, like below 0F or colder.]

99% of the fuel I burn is from owned tanks, and is triple filtered.
Waxing is mostly a thing of the past; Filters tend to last a 
real long time.   [Cut one open at 75k, and it looked new,
with very very little visible dirt.]

Brittle plastic lines, and cracks in rubber (neoprene) lines, tend to 
happen more often than clogged filters.

BUT, if you find that your engine starts stumbling, not on a short
burst of high power demand, but on sustained high power demands,
then I would rule out the fuel filter and replace it.  

It's an old habit from the early days of owning VWdiesels, but every 
VWdiesel I own has a spare filter in the trunk.  It's real easy, 
especially on a trip, using somewhat unfamiliar fuel sources, to get
a bad batch.  Eventually that filter gets rotated into service.

(I still have some of the old late 70's style filters though.)

I hope I answered your question, while rambling.

Oh, old trick when experiencing waxing...heat the fuel filter to warm
(+100F) with a propane torch.  If idling/running improves, and the bubble 
count drops drastically, you probably have waxing, or water ice crystals.
If not, and you still have bubbles, either a filter change or leak
fix is appropriate. 

Val