At 11:20 PM 3/10/2011, Anthony Egeln wrote:
>We've pretty much given up on attempts to repair the stock coolant
>temp gauge & sensor system.  Have swapped out the instrument
>cluster, replaced the sensor and walked the wire. Still pegging max
>high with a steady flashing light, but the thermal laser gun reveals
>a normal temp system.
>There was a posting recently on "slime" affecting the level sensor
>in the pressure tank, and I plan to share that with the tech.  I
>suppose that would only affect the blincking light anyway, not the
>temperature reading.

Didn't you and I start chasing this?  What happened?  I know this
system inside out.

>The tech working on it has found a completely independent (of the
>stock system) aftermarket coolant temp gauge and sensor and he plans
>to install that over the next two days.
>One thing is unanswered in my mind.  Does the stock sensor give
>temperature readings to the ECU?  I'm wondering if this is one of
>the reasons why my fuel economy has dropped from 18-19 to 16-17,
>i.e. running rich.  Furthermore, if the ECU does get data from the
>stock system, how will the aftermarket system get tied into the ECU?

There are two sensors.  One faces forward from the thermostat housing
and one faces to the left.  The blue one is for the ECU and the black
one for the gauge.

I urge you to pmail me and let us solve this systematically instead
of throwing parts at it.

Yours,
David