Coolant temperature sensor question.

[Huw Powell]

> I'm still diagnosing a cold running problem in my 87 4KCSQ. I checked the
> resistance on the NTC Coolant Temp sensor (the bottom one on the upper rad
> hose flange) and came up with about 8.7K ohms at @ 40 deg F. Bentley says
> 2.5K ohms @ 68 deg. F.
> 
> Is 8.7K ohms too high for 40 deg F? The Bentley only says resistance "is
> higher above 68F" or something similarly vague......

sound like you need a new one.  since the resistance is supposed to rise
with temperature (or is it?  that wouldn't be NTC it would be PTC) then
yours being higher at lower temp would be bad.  Might want to read that
spec again to be sure!  I thought there was a resistance spec for a
lower temperature, too.  substituting a known value fixed resistor set
to the "cold" spec can be a quickie way of checking if that is where the
problem lies too.

-- 
Huw Powell

http://www.humanspeakers.com

http://www.humanthoughts.org