Ian Vincent Posted March 23 Report Share Posted March 23 (edited) The title of the topic says it all really. Up until this year the temperature gauge on my TR3a has been very reliable and then a couple of days ago during a break from the incessant rain that we have been experiencing for the last few months, I took the car out for a run. The car was running sweetly and I did about 20 miles at varying speeds before I noticed that the temperature gauge hadn't got up to its normal operating range. I guess it took a while for me to notice it because it was a fairly chilly day. Anyway I then watched the gauge closely for the remainder of my trip (about another 10 to 15 miles), and whilst it was certainly responding to changes in temperature, e.g. when I was stationary waiting for traffic lights, it wasn't behaving normally. So when I got home, I left the car idling outside my house for a while and sure enough the electric fan kicked in when I would have expected it to but the gauge was indicating about midway between the 90 Deg F and 185 Deg F rather than just over the 185 point where it normally does. Are there any clever ways of isolating the problem, apart from removing the temperature probe from the thermostat head and dunking it in boiling water - and I'm not sure what that would tell me anyway because the otter switch on the electric fan is telling me that the water is hot. All ideas gratefully received. Rgds Ian Edited March 23 by Ian Vincent Quote Link to post Share on other sites
RobH Posted March 23 Report Share Posted March 23 No there's no other way of testing the capillary type gauge Ian. It's possible yours has lost some of its ether due to a fracture in the pipe or there may be something wrong with the bourdon tube connection to the needle. Quote Link to post Share on other sites
iain Posted March 23 Report Share Posted March 23 Ian, I had a similar issue with my gauge after a rebuild due to a cracked capillary tube.I tested it every which way and it still under recorded. I used IR gauge on the stat housing the rad and everywhere else you can think……the car was genuinely running cool! I then removed the bypass partial closing piece and viola al was back to normal! Just love Tr’s :-) Quote Link to post Share on other sites
james christie Posted March 23 Report Share Posted March 23 I have experienced this a couple of times after a winter break. I have managed to remediate the under reading by adding some coolant -even a lot of coolant - and then let the car get really hot on tick over with the front end well raised. My deduction is that an airlock forms in the bulb/ thermostat housing. james Quote Link to post Share on other sites
Ian Vincent Posted March 23 Author Report Share Posted March 23 2 hours ago, james christie said: I have experienced this a couple of times after a winter break. I have managed to remediate the under reading by adding some coolant -even a lot of coolant - and then let the car get really hot on tick over with the front end well raised. My deduction is that an airlock forms in the bulb/ thermostat housing. james Good suggestion, I’ll give it a go tomorrow. Thanks. Rgds Ian Quote Link to post Share on other sites
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