High Temperature?

[Poledriver]

Had a strange one yesterday with my 450 wedge. Drove around 80 miles in the afternoon, temperature quite happy between 80-95 and fairly stable compared to how I was driving. I have a manual cooling fan switch (replacing Otter switch soon!) and did not need to use it at all! Stopped for a couple of hours then headed back home. Temperature kept shooting up to the red area and then coming back down to about 85, using the manual fan switch did not seem to have any effect! Driving style was about the same to start with but I calmed it down a bit when temp went erratic, checked water level when I got home and it was fine!

Any thoughts??

[adam quantrill]

Did you turn off the heater?

Sometimes this affects the circulation and the thermostat goes into a hard on/off mode where it seems to be cycling. This can be exacerbated by air in the system.

I'm not sure what to suggest but you might want to check the thermostat has a small bypass hole preferably with one of those tadpole things in it. While it's out check it opens and closes at the right temperatures.

Mine will go right up ino the red when warming up - with the heater off - but just goes up to 100 and stops with the heater on.

[JR]

An air lock.

[KJR]

Had something similar many years ago.

In my case it was one of the wires connected to the temperature sensor "falling apart".

[Poledriver]

Thanks:-
Didn't touch the heater control, it was on all of the time!
Had checked for airlocks before in the metal pipe from rad, are there any other procedures for bleeding air from system?
Will check wiring tomorrow evening.
Could it be connected with the fuel gauge bouncing up and down? Are the dash electonice controlled with a voltage regulator?

[djc1001]

Voltage reg. can affect all elect instruments. Had some strange issues which all disappeared with a new reg.

david