Re: Radiator Fan Afterrun

[James Marriott <marriott@pophost.micron.net>]

Haudi,

>>On my 87 5ktq the electric coolant pump is missing and the radiator fan runs
>>for a long time after the car is turned off (after what I am led to
believe is
>>the couple of minute soak period). I have a new battery, but this morning it
>>wasn't powerful enough to start the car (-16 degF). How can I diable the
>>afterrun radiator system or at least shorten it by 3/4?
>
>Please ignore my previous post on this. I hadn't had enough coffee yet.
>
>If the pump is missing, then no cooling happens and the thermoswitch
>continues to let the fan know about it for a long time. You really
>should consider replacing the pump as soon as you are able.
>
>This brings up a related issue. Some folks experienceing long after-run
>cooling times may have a faulty pump without realizing it.

In addition, they have a faulty relay. Even shorting the water-neck switch
(BTDT to cool a hot engine) should only make the pump run for 10-15 minutes
(200q).

>One common
>failure mode for the auxiliary cooling pump is that the impeller siezes
>and the motor continues to run (the coupling is magnetic, I believe, not
>direct). You can check whether water is actually being circulated by
>pinching off the hoses with your fingers and feeling whether water is
>moving while the pump is running.

Short the switch, pull the AF relay (to quiet the fan), and listen for
slight gurgle/whoosh sounds from the $9k "Y" hose. As has been noted, pump
noise is not an indication of proper operation.


cu
James
'87 4kq (alias "late-B2 90q")
'89 200q (K26, torsen, aero handles, no bag)
'86 4ks, lives on in memory
http://netnow.micron.net/~marriott
Boise, ID, USA