Checklist for Reliability of Older Audis

[Huw Powell]

>
> 1.) Dielectric grease is used, if I recall, to help conduct heat between
> (for example) a power amp and its heat sink. Its an electrical
> insulator. Did you mean something else when you said to "Undo all the
> electrical connectors, clean, add dielectric grease, and reassemble? "

I meant EXACTLY what I wrote.  Silicon dielectric grease isolates 
against water and improves conductivity over very short distances.

>
> Whats the best substance to put on electrical conductors to ensure that
> they keep conducting? In other instances I've used "electrical contact
> cleaner", which is essentially aerosolized alcohol and heptane. Its good
> for cleaning contacts, but leaves no residue. Is there something thats
> good for preventing the audi glitches that come from oxidized contacts,
> such as WD-40? Everything from the "power-window switch syndrome" to
> this current case of "ground signal from ECU not working"

WD-40?  You're kidding, right?  Cleaner then dielectric.  WD-40 is for 
keeping tools from rusting.  Post-87 power window switches are sealed 
and need no maintenance other than replacing the little lights once in a 
while.

> 2.) You mentioned, "on your next timing belt change". How often should a
> timing belt be changed in an I5? And are there any symptoms of a worn
> timing belt that usually occur before the belt actually slips?

5 years/60k miles, whichever comes first.  It's in the manual.  TBs 
don't "slip", they "skip teeth".  And, no.  What they usually do when 
run too long is break, which is only a big deal if you have an 
interference engine.  Otherwise you are just stranded.

> 4.) It was commented that Audi Bosch coils essentially never go bad. But
> I've also read that the Beru coils were an improved electronic design
> from the original cylindrical Bosch, in the same way that the Piersburg
> fuel pumps seem to do better than the original Bosch fuel pumps. Any
> opinions?

Not from me, no.  Running an ex-Audi Bosch coil on my '57 Trojan loader, 
works fine.