Lotus Elan and Lotus Elan Plus 2 Forums

You caqn always bring out a pot of boiling water - the larger the better to prevent too much temperature loss - and just immerse the sensor rather than removing the whole instrument from the car.

One time when I did it I used one of those picnic tea maker immersion heaters (12 volt) in a large mug of water.

Why not?! It certainly does the job as well as any other method!

From your post, I did not see anything out of line as far as the running of the car, temps, pressures etc. Now if you told me the car was running at 110 degrees, then that is something.

Have you ever told us what you have for cooling? Is there an electric fan, or just the blades mounted on the water pump pulley?

Hi Tony,

It has no electric fan, just the old two blade unit which cools the radiator from the engine side.
But the previous owner did install an aluminum radiator and also a new plastic filler tank (similar to the ones
in the very late original twin point minis) which is placed directly above the constructor's plaque on the top right hand side of the engine.
But as I said, the last time I drove home in traffic the termperature went all the way up to 110? and stayed there during half the journey whereas yesterday it remained between 70 and 90?. I suspect due to the empty roads and the cold weather. The test will be taking her out when the weather warms up.

When I tested my gauge a little while ago, I set up the workmate alongside the car, place a camping burner on it, boiled a pan of water and removed the sensor from the thermostat housing and placed it straight in the pan. I also had the kitchen thermometer in the pan as well.

That way as the water heated up I could compare incremental changes.

Interestingly, I started off with the thermometer case touching the base of the pan & the sensor suspended with garden wire, & there was a 10 degree difference between the gauge & the thermometer reading. Once I suspended the thermometer they evened up.

In my opinion, all your car needs is an electric fan. Remove the blades from the water pump once you get the electric fan. The additional rotational mass on the water pump does not help the longevity of the pump, but in my opinion what does pumps more harm is inactivity. Keep the pump rotated ninety degrees every month when car not in use.

richardcox_lotus wrote:Interestingly, I started off with the thermometer case touching the base of the pan & the sensor suspended with garden wire, & there was a 10 degree difference between the gauge & the thermometer reading. Once I suspended the thermometer they evened up.

This reminded me of a previous discussion on checking the gauge.
When I had my temperature gauge repaired it came back with a warning against "kettle testing" and when questioned they explained this was because of the danger of damage to the gauge which might result if the sensing bulb contacts the kettle element (or in this case the base of the pan in contact with the heat source) which may exceed the temperature of the boiling water. Although this possibility was comprehensively dismissed by a couple of posters at the time I mention it again just in case it has some merit. Suspending the sensor as you have done avoids the risk of damage anyway - better safe than sorry!
engine-exhaust-cooling-f39/checking-refurbished-water-temp-gauge-t22670.html