Re: Pre-purchase advice

[Wallace White <wallace@remdesign.com>]

Bernard Littau wrote:
> 
> I am very close to making an offer on a '86 5ktqw (or is it 5kqtw?  I'm
> still working on the lingo :-).

5kcstqw, if you want to make it really long!

> I have never owned a turbo anything.  Color me nervous.  What should I be
> looking for in the engine compartment as possible warning signs?

These cars have an electric, auxiliary coolant pump, which will run at
the same time as the radiator fan after the engine is shut off (if
needed). The turbo itself is water-cooled. The previous ('85 and
earlier) Audi turbos were not water-cooled and are something to worry
about at high miles, but these ones are generally very long-lived. The
aux coolant pumps, however, are not. You can check its operation by
removing the radiator 1st speed relay (in the relay/fuse panel under the
hood; its the top-right relay) while the radiator fan is running after
shutdown. (You can also trigger the after-run by shorting the two-wire
thermoswitch, sticking off the back of the engine's upper coolant pipe.)
By pulling the radiator relay, only the pump should be running, so you
can hear it. Others have suggested pinching the output hose from it. If
the pitch of the pump changes, it's working; if not, the impeller may
have broken.

This is a pretty easy thing to check and it might be a useful bargaining
point. "Hey, your turbo coolant pump isn't working on this car you're
selling..." The pump is about $120 at the very least, and they do fail
often. The $100 after-run relay fails frequently too, when the pump
seizes, but they're easily repairable. See Avi Meron's recent post about
an alternate pump. HTH.

- Wallace
  '87 5kcstq 152k