temp guage too low

[paddysaab]

I changed the thermostat because the temp gauge was barely moving. This didn't solve the problem. Is the temp sensor the next step and is that it near the thermostat?

1997 2.3 CD Griffin

[Paul @ Kippen]

paddysaab,

Ah Ha,  that's the question ! Yes,  it's the sensor just beside the 'stat housing which drives the gauge.  The one on the back of the head in the middle of the inlet manifold controls the mixture, and the one in the top of the radiator runs the fan.  All clear so far !

Did you check out the 'old' stat when you took it out.  Was it sitting partially open at ambient temps - should be tight shut this weather.  Stick it in a pan of water on the stove. It should start to open near to the stated temperature.  OK, so most of us don't have a suitable thermometer.   If you watch until little bubbles start to form on the bottom of the pan you won't be far off 80 centigrade.  Time from then to a rolling boil and a linear time / temperature relationship won't be too far off.  It should go from shut to open over about 5 degrees.

Paul @ Kippen.

[phoenix]

Struggling to remember here... when the control of the temp gauge on the dash moved from direct reading from the probe on the stat housing (circa MY95) to stop the large fluctuations, was that probe not then ditched in favour of the one on the manifold?

[racingsnake]

I remember someone saying that post about MY95 the temp gauge was driven by the ECU rather than by the temp sensor direct, don't know if that is true though.

I have moved over to here as the adverts were driving me mad, the old site is just about un-usable!!!

Cheers

Richard
(Racingsnake from Preston, Lancs)

[phoenix]

Yes, later model temp gauges were definitely ECU driven I just can't remember which sensor they use

Welcome to STT racingsnake Good to have you on board

[paddysaab]

Thanks for the replies.
When I took out the old stat, it was tightly closed. It opened about the same temp as the new one but closed quicker.
The fan comes on when the gauge is about 4mm above the blue part and never goes much higher. Actual engine temp seems fine but mileage is slightly down (27ish) so the car must be running a little rich.

[alang]

Just checked the '96 (with the placebo gauge) outside and it does not appear to have the sender by the thermostat, so I assume it is all driven by the sensor at the back of the head.   My son has the '94 now so i can't compare.

[Thorfinn]

I have now had two 9000s with this fault - a recent encounter with a TECH 2 rig revealed that the gauge itself was consistently under-reading - and on other forums (fora?) I have heard of the same thing happening. So don't assume it's the thermostat or the sensor!

Anyway, it looks to me like the thermostat is a sod to get to...or am i being pessimistic here?