Ny replacement 86 900 Turbo seems determined to give me heart failure. Since I
bought it a coule of weeks ago the it seems to have been running very hot-the
test drive was at night and gave no indication (I know-never buy a car at
night). But the car shows no signs of overheating. As a precaution I change the
thermostat-no change. So I took it to the shop yesterday and we stuck a
thermomator in the coolant-195 degrees. So why am I getting high gauge
readings? Sender? Gauge? I got a parts car with all good parts so what do I do?
Phil Brown

Phil Brown wrote:
Does the fan kick in at a particularly high temperature, or does
the temperature get very high despite the fan being on?

--
Grunff

Phil Brown wrote:
Don't assume that the temperature of the coolant in the
reservoir is the same as that everywhere else. For instance, an
eroded water pump impeller, or a blockage somewhere would [a]
cause the increased temperature and [b] keep the temperature in
the reservoir lower than the rest of the system.

But if you're sure it's the reading, then I really don't know -
senders and gauges never fail by reading a few % out - they just
fail.

Could be that you have a voltage leak onto the sender/gauge
circuit. What does the gauge read when the engine is cold? That
is, is it offset at all?

--
Grunff

Unlikely. Laws of thermodynamics and all that. however, I still have'nt ruled
out a high coolant temp at the sender due to some anomily.

Nope, seems normal. I'm going to bleed the system yet again today just to be
safe.
Phil Brown

Phil Brown wrote:
The laws of thermodynamics certainly allow one part of the
system to be at a different temperature. Bear in mind that this
is not a steady state system - the amount of energy enetring the
coolant from the engine is constantly varying, as is the amount
of heat lost at the radiator. Just because the coolant at the
sensor occasionally peaks at 85C doesn't mean that the coolant
in the reservoir would ever reach that temperature.

--
Grunff