Good day Gents, am having some trouble with the cooling system of my '87 TR. The car runs fine and does NOT overheat, however, once the rad fans goes on, if the car stands still, they will not switch off anymore. Whilst the fans are running the temp does not raise but does not drop lower enough for the fans to switch off. It suffice the cars moves to get the temp low enough for the fans to switch off. Have already replaced the original fans (4blades) with later ones (5 blades) but this has not cure the problem. Have had the rads re-cored few years ago, so they cannot be clogged. Have replaced all the hoses with scuderia rampante kit. Have pressure tested the system up to 1 bar, and whilst there are no visible leaks, the pressure drops to 0.5 bar in abt 30 mins and to zero in another 30 mins. Do not have any sign of oil in the expansion tank or its cap, however, if fill the tanks to the prescribed 6 cm from the top and go for a spin, once back and cooled off the level is down by abt 3 cm. Leaving the level untouched and driving the car for 500 kms it does not change. The car does not smoke white. Any word of wisdom ? Tks a lot Gianni
I think that this is a problem of the waterpump check the engine oil if there is coolant inside what I guess. the coolant level about 3 cm lower than normal and it stays I think is only an optical sign. try to refill and you will see that much more coolant you may put in. so in the whole system there is coolant missing and in the top of the radiators there may be air, so yo may bleed the complete system ( 3 bleeders ) after refilling coolant.
Not sure that you even have a problem. If both coolant radiator fans are running, and the temp never goes above 95~100 deg C there's no functional issue IMO. Idling stationary for long periods of time isn't something that I do often so can't confirm/deny if my fans do go off, or not, in that condition, but can confirm with some reasonable coachwork motion (on a not hot day) they will go off.
I kind of agree with Steve. The coolant level is not an issue to me. The air space required as stated in the book is an approximation and the fact that it stays stable long term strongly suggests to me you have no issue there. The one place I differ is unless a very hot day the fans will cycle on and off. At right about 100 on your gauge they should go on and drop to 90 or so and go back off. I have experienced many TR's that were not properly bled and worked almost OK. They can be a little difficult to bleed because the filler and the bleeders and the upper components of the cooling system are so close in height. I'd suggest getting an Air Lift cooling system filler and trying that prior to taking anything apart. Id also check the polarity of the radiator fans, be sure they are blowing in the correct direction and test with a volt meter to be sure they are getting full power. You might also test the water temp with a simple thermometer to be sure it is correct as well.
Does the reading on the gauge actually move lower once the fans come "on" and have run for a while, or does the temp gauge reading just stay the same no matter how long the fans have run?
Tks for the replies guys. Do sincerely appreciate. @ Steve the temp drop and the gauge move down when the fan goes on, simply not lower enough to cycle the fan off. ?Wonder if temp the sensor in the left rad is the culprit ? @ rifledriver the fan turn in the right direction. Not sure abt gettimg full power. As to bleeding have been trying few times. Do personally believe there is air pocket trapped somewhere in the system. Have lifted the car on one side to remove one wheel and once reached a certain angle hear 'swashhhh' the typical noise of water moving from one side to the other which, correct me if am wrong, should not be hearing if the system would be full of water. Have an infrared thermo and will certainly take some measurements. Good idea. Tks. @turbo joe not sure abt water in oil. certainly no oil in water in the expansion tank. Best, Gianni
at the waterpump there is no oil pressure, but water pressure and you have written it will loose water but not draining somewhere. so I think it is going coolant into the oil - and this only would be possible at the waterpump
Water level is not going down. I bet his pressure tester is leaking. It is quite common. If he was losing water as fast as the pressure test bleeds off it would be no secret where it was going by now.
Yeeep, would have seen it dripping on the floor from somewhere. Will check the oil dipstick tomorrom but am fairly convinced it will show no sign of moisture.
That's definitely not a bad sign that the needle does move down when the fans come "on". For the thermoswitch, your OM indicates the nominal change to get down to the "fan turn off temp" from the "fan turn on temp" would be 9 deg C lower (the absolute temperature values given in the OM won't match what's shown on the gauge because the thermoswitch is mounted in the lower radiator tank while the thermister for the temp gauge is in the Y-pipe on top of the engine). Consequently, one fairly simple diagnostic test for the thermoswitch would be to just note what the temperature gauge reads when the fans switch "on" and when the fans switch "off" (when you are moving) -- if the difference between those two indicated temperatures is much larger than 9 deg C = you could try replacing the thermoswitch.
Tks Steve, will try with an infrared thermo to check the temp delta bewteen fans on and off. Incidentally no sign of water on the oil stick.
that is a very good sign but where the coolant will go??? when not leaking on the ground??? you may check the heating valve and the heating radiator for leaks. somewhere the coolant has to go
Is an option indeed, however, and this is what puzzles me, the level in the expansion tanks goes down to abt 3 cm and then stays there. It does not drop any further (have checked after 500 km and no change in level). Had it be the gasket, the level would continue dropping using the car. On top would see smoke (white) at the exhaust which do not have.
As I said from the start. I do not believe you have a coolant loss problem. I wouldn't dedicate any time on that.
I'try to get an air lift system which will certainly come handy also for the other cars in my garage.....have to check who sells it on this side of the pond.
