cj79 Posted July 17, 2014 Report Share Posted July 17, 2014 Hi All, I have noticed that over the past month the temp gauge has steadily been getting warmer, it now sits between one mark before the end of scale and way off in the red. I have a brand new radiator, new water pump, completely restored engine, new Revotec fan (which I mounted the grill side of the radiator - flipping the polarity as the original fan mount was in the way and I was using that to get the spanner on to tweak the engine timing at the time). I've filled it with Evans waterless coolant and although I know the fan may not be as efficient mounted the wrong side of the radiator it does seems to be pushing a lot of air through. Having read a lot of threads on overheating the fan shouldn't make as much difference as i'm noticing.. even on cool days i'm way into the red. Does anybody have any suggestions on what to try? Many thanks,Chris Quote Link to post Share on other sites
Guest ntc Posted July 17, 2014 Report Share Posted July 17, 2014 Yep Dump the Evans coolant. Quote Link to post Share on other sites
jerrytr5 Posted July 17, 2014 Report Share Posted July 17, 2014 Duff thermostat. Test it in a pan of water with a thermometer. If you try two or three at once you will probably see quite a difference. Many are slow to open or just don't open enough. Jerry Quote Link to post Share on other sites
Denis Posted July 17, 2014 Report Share Posted July 17, 2014 Yeah Dump the Evans! Water and Antfreeze all year round is the way....My TR runs so cool I have to blank part the Rad off ! At first I thought it must be the Gauge or Sender, changed em both...made no differance, even in this summer tempreture, it has the original constant plastic fan too! Quote Link to post Share on other sites
Peter Cobbold Posted July 17, 2014 Report Share Posted July 17, 2014 (edited) Yep Dump the Evans coolant. +1 Â Chris, The waterless stuff hinders heat transfer form the cylinders to the water jacket, and from the water to the air in radiator. http://www.tr-register.co.uk/forums/index.php?/topic/44837-waterless-coolant/ Hotter combustion chambers are not necessarily a bad thing for a lightly loaded engine - a bit better feul economy. But I'd worry about whats happening during hard and fast running. Not for me. The coolant wont boil easily so you dont need to worry about that, it will run well into the red on the gauge, and maybe beyond - without boiling.Nor will it blow hoses off. Peter Edited July 17, 2014 by Peter Cobbold Quote Link to post Share on other sites
john.r.davies Posted July 17, 2014 Report Share Posted July 17, 2014 Check that the sensor and gauge are functioning correctly. Â One way is to buy some temperature tabs, sticky labels that change colour to show the highest temp reached For example: http://www.ebay.co.uk/itm/Cylinder-head-Engine-block-heat-tab-temperature-stickers-x10-/261510190021?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3ce338d3c5#ht_1285wt_721 A remote infrared thermometer is usfeul - take the temp of any part while the engine runs! http://www.ebay.co.uk/sch/i.html?_odkw=infra+red&_osacat=0&_from=R40&_trksid=p2045573.m570.l1311.R1.TR11.TRC1.A0.H1&_nkw=infrared+thermometer&_sacat=0 Â Or else to take out the sensor, run it on a long lead to a work bench and pop it ina a pan of water over a camping stove. Observe the gauge reading as you heat the water. This will show you what the sensor/guage rig reads at 100C. Although the engine will run at more that that as it's under pressure you can see the way the curve is going. Â You have a rebuilt engine etc. I'll bet the sensor is new too, and new sensors, like so many pattern parts, are badly made. Try an old sensor, they can last forever! Â John Quote Link to post Share on other sites
RogerH Posted July 17, 2014 Report Share Posted July 17, 2014 (edited) Hi Chris, as stated above the Evans, although boil proof, will actually increase your engine temp. Have you got the correct sensor - I believe they are colour coded. You could pop a summer thermostat in the engine (76' for summer and 84 for winter). Â If you use an infra red sensor to measure your engine temp paint the sensing area with matt black paint. Colour variation will effect the temp reading. Â The pusher fan is not the problem - it will work. Â Roger Edited July 18, 2014 by RogerH Quote Link to post Share on other sites
john.r.davies Posted July 17, 2014 Report Share Posted July 17, 2014 No argument, Roger, but most hoses, unless you have re-equipped with fancy Samco, are a nice matt black already! John Quote Link to post Share on other sites
RobinTR6 Posted July 17, 2014 Report Share Posted July 17, 2014 (edited) Had this with a new sensor, went back to the old one and gauge now working correctly..which came with the engine which hadn't been run for 10 yrs ++. Edited July 17, 2014 by RobinTR6 Quote Link to post Share on other sites
Andy Moltu Posted July 18, 2014 Report Share Posted July 18, 2014 Is your Revotec fan switching on? Is it running in the correct direction? Quote Link to post Share on other sites
Dean Posted July 18, 2014 Report Share Posted July 18, 2014 It could be that the voltage stabilizer is bad. It should put 10 volts on the gauge. it will also make the fuel gauge read high also. It is mounted on the back of the speedometer on the TR6. Must have a good ground to the mounting tab. Â Dean T. Quote Link to post Share on other sites
Mike Collins Posted July 18, 2014 Report Share Posted July 18, 2014 Most DC motors will happily run in the opposite direction with a polarity change, but is the blade aerofoil able to move air when reversed? Â Some of the fans I have lying around have assymetric blades and move very little air when reversed. Â Mike. Quote Link to post Share on other sites
peejay4A Posted July 18, 2014 Report Share Posted July 18, 2014 (edited) Only permanent magnet motors or some electronically commutated motors will run backwards on a polarity change. Wound field motors like wiper and heater fan motors will run in the same direction regardless of supply polarity. Edited July 18, 2014 by peejay4A Quote Link to post Share on other sites
littlejim Posted July 19, 2014 Report Share Posted July 19, 2014 I'd throw in rechecking the timing and tuning. Mine read high on the temp gauge when the timing was a bit off. Quote Link to post Share on other sites
Andy Moltu Posted July 19, 2014 Report Share Posted July 19, 2014 Work from the basic premise that the cooling system on the TR6 is more than ample when in good nick as our fellow drivers in the USA and Australia will no doubt confirm. Â If it is overheating then something is likely to be wrong with the cooling system (assuming the gauge and sensor is ok). Waterless coolant isn't going to adversely affect heat transfer in UK temperatures enough to render a healthy cooling system so much less efficient as to run hot in the UK. Â Then you have to work out if your engine is producing too much heat - lean mix, retarded, head gasket failure or cracked head/block or whether if is a lack of cooling capacity - silted up rad, water pump failure, leaks or electric fan problem (the fan is irrelevant once you are moving at more than a few mph) so if it overheats on a run you probably have to look beyond your fan. Quote Link to post Share on other sites
dblenk Posted July 19, 2014 Report Share Posted July 19, 2014 Check that the sensor and gauge are functioning correctly. Â One way is to buy some temperature tabs, sticky labels that change colour to show the highest temp reached For example: http://www.ebay.co.uk/itm/Cylinder-head-Engine-block-heat-tab-temperature-stickers-x10-/261510190021?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3ce338d3c5#ht_1285wt_721 A remote infrared thermometer is usfeul - take the temp of any part while the engine runs! http://www.ebay.co.uk/sch/i.html?_odkw=infra+red&_osacat=0&_from=R40&_trksid=p2045573.m570.l1311.R1.TR11.TRC1.A0.H1&_nkw=infra red+thermometer&_sacat=0 Â Or else to take out the sensor, run it on a long lead to a work bench and pop it ina a pan of water over a camping stove. Observe the gauge reading as you heat the water. This will show you what the sensor/guage rig reads at 100C. Although the engine will run at more that that as it's under pressure you can see the way the curve is going. Â You have a rebuilt engine etc. I'll bet the sensor is new too, and new sensors, like so many pattern parts, are badly made. Try an old sensor, they can last forever! Â John Hi john good link about the temp sensor for a tenner however looks like they are fronts for gear from china and never arrived been there done that anyone bought one of these that got delivered and worked Cheers David Quote Link to post Share on other sites
john.r.davies Posted July 19, 2014 Report Share Posted July 19, 2014 David, Maybe from China originally, but the address is Farnham and the seller has 2250 sales and a red star for good conduct. Quality GoK, but delivery assured, I wouwld think.  These are from America (but probably Made in Chinam and beware inport duty to UK) http://www.ebay.co.uk/itm/Factory-Effex-Engine-Temp-Temperature-Stickers-3-Pack-/231112477675  Or same thing as first, from UK, single stickers at same price: http://www.ldsengineering.co.uk/Cylinder_head_engine_block_temperature_sticker_17mm/p340129_3771498.aspx  OR, in ?Netherlands? EU anaywya, so no import duty: http://www.tqc.eu/en/products/article/temperature-indication-stickers  OR, if you want the widest range of products and temperatures, THE company, and in the UK: http://temperature-indicators.co.uk/acatalog/industrial_adhesive_indicator_strips_and_labels.html  JOhn Quote Link to post Share on other sites
dblenk Posted July 20, 2014 Report Share Posted July 20, 2014 (edited) Excellent john Thanks for the help Any of the hand held units recommended Some said didn't work we're **** etc I know what do you get for a tenner these days but would rather pay more and get it to work David Edited July 20, 2014 by dblenk Quote Link to post Share on other sites
cj79 Posted July 22, 2014 Author Report Share Posted July 22, 2014 OK so I took the front cowling off and found the remains of the old overflow bottle bracket... sans bottle. It's probably lying by the side of the road out in the dales somewhere! The coolant was overflowing through the pipe at the top of the rad and onto the road.. I put a new bottle in, topped up the coolant ( put a summer thermostat in - thanks Roger) and now it's sitting about halfway, it's scorching hot today and i've been out for a couple of hours without it creeping over so hopefully that should be that.. I am a little concerned about my choice of coolant after reading all of your comments though. Maybe I should switch.. Many thanks for the advice! Chris Quote Link to post Share on other sites
Peter Cobbold Posted July 22, 2014 Report Share Posted July 22, 2014 I am a little concerned about my choice of coolant after reading all of your comments though. Maybe I should switch.. Many thanks for the advice! Chris Chris, I would not worry - now you've found the cure. Waterless wont shift heat anywhere near as fast as water, but ordinary road driving makes very liitle heat compared with a TR6 at sustained max power. And your cooling system with the new thermosat can cope with the poor heat transfer, as the gauge shows. Peter Quote Link to post Share on other sites
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