My neighbour with a Triumph TR3 was persuaded by the crowd that he should use Evans coolant. Basically this is pure glycol - it doesnt absorb heat as well as water, but can survive running hotter. With the pressure relief in the cooling system at 7PSI .. (which turns out to be irrelevant if you dont have water...) For some vehicles this works perfectly well - engine runs hotter but doesnt boil over so it does not appear to be an issue .. however .. He left it idling this afternoon, and he said "The temperature gauge is a reconditioned gauge (vapour bulb and capilliary tube to Bourdon gauge) , I just paid £130 and it doesnt work" "The oil pressure seems a bit low" "The other day, a coolant pipe was leaking and the engine was steaming, scared people at Tescos with a cloud of white stuff, they thought it was on fire... " - this was allegedly a crack in a soldered joint on an aftermarket brass fitting jammed in a chromed "dress up" pipe going to the cylinder head.. but probably actually glycol going into the engine from a leaking head gasket.. as we saw later A bit later this afternoon, the crank case breather was producing vaping style "steam" and the exhaust was also producing massive amounts of "steam". Head gasket had gone, and the lack of a temperature gauge plus the Evans meant it didnt blow the pressure relief valve on the cooling system before the cylinder head was over about 120C, at which point it let go -- it felt very hot to my hand, and checked with an IR thermometer on black sections it was that hot.. Using the same thermometer on the chromed rocker box cover, it said 21 degrees C, despite having the same really hot feeling .. - too reflective. Interestingly the thermostat was sitting at 90 degrees C , and closed as the radiator side was 65C .. , keeping a big lake of really hot Evans stored up in the head that didnt conduct heat well enough to the thermostat to open it.. Evans coolant doesnt boil until 190C.. So to create pressure in the coolant loop you have to really cook the engine. So instead the head warps until the head gasket lets go. Another negative for Evans ...
He showed me the pictures leak between cylinders 3 and 4 and the coolant loop. The garage reported the head gasket was installed without sealant as a likely cause.. guess which garage fitted the head gasket.. Hope was raised of a free repair ...
Shouldn't need sealant if the head and block are true, which they should have checked on the previous occasion. I think I'd take the car elsewhere...
I think I vote for the head warping at well over 100C because Evans coolant does not boil until over 190C , meaning that the vapour pressure is so low it doesn't blow the pressure relief valve until the cast iron head is well off the scale.. shades of my bus where the head temperature sensor reads about 120C max. Until I got foam in the fan then it said 190C and one head cracked..because over 150C , aluminium is losing it. The first time the TR3 failed it apparently recovered totally when it cooled down. Why do they sell such snake oil ? Everywhere where science and technical data exist, it says that pure ethylene or propylene glycol coolant also freezes at a higher temperature than when mixed 50:50 with water, as well as pure glycol being 2x less thermally conductive and having less than half the thermal capacity of water, so adding water to it is all round better.
Just as well we don't have water-cooled engines because... We'd have several 129-page long threads of 'What coolant?'
