Discussion
There have been many posts on here regarding engine temps but i just had a question regarding when the car is deamed to be up to temperature? My Chim has a 2 stage fan fitted that where the temp that the fan kicks in at can be adjusted. The previous owner has this set to cut in at half speed at 70 deg and full speed at 90 deg should it get that high. I have found that the car is rarely above 75 deg even in traffic but usually when crusing aroung 65 deg. Should this fan initially kick in at the higher temp or the general opinion be that its ok?
It has an after market couple of dials under the engine bay which allows the user to manually adjust the fans to cut in at any given temp. They are currently set so that both fans come on at half speed at 70 deg and apparantly full speed at 90 although they havent ever got that high. Would you suggest adjusting them then?
i would suggest that even with the fans you have got the fact that you have NEVER seen your engine approach 90 degrees even after being left to idle, probably means that your temp sender is wrong. on the other hand you could have MEGA fans or an ally radiator or something to OTT.
however don't worry too much. as long as it never overheats you are probably fine.
a better measure of adequate temp for hooning may be oil pressure. on mine it will idle cold at about 33 psi. when at temp it will idle about 16-18. I know she is lubed and ready for fun at this point.
however don't worry too much. as long as it never overheats you are probably fine.
a better measure of adequate temp for hooning may be oil pressure. on mine it will idle cold at about 33 psi. when at temp it will idle about 16-18. I know she is lubed and ready for fun at this point.
Edited by thegman on Friday 2nd May 14:26
My Chimps Oil pressure is on the mark between 30 and 60 when cold and then only drops to just above 30 when very hot indeed.
My temp guage reads 10 degrees low. Worth getting them checked with one of those heat detecting gun thingies.
During the winter the car runs under 75 degrees on A roads from cold and will warm up to the thermostat (82 degrees) when idling for a short time. If I get stuck in traffic for a while it very gradually rises to 90 degrees and the fans come on and keep it just under. If I travel at motorway speeds it rises to the thermostat again, If I go very fast (on a track of course) the temperature decreases to about 70 degrees.
My temp guage reads 10 degrees low. Worth getting them checked with one of those heat detecting gun thingies.
During the winter the car runs under 75 degrees on A roads from cold and will warm up to the thermostat (82 degrees) when idling for a short time. If I get stuck in traffic for a while it very gradually rises to 90 degrees and the fans come on and keep it just under. If I travel at motorway speeds it rises to the thermostat again, If I go very fast (on a track of course) the temperature decreases to about 70 degrees.
It's a pity that TVR fitted gauges with actual temperature readings on them unlike ones with a cold/normal/hot range as it's easy to get hung up on actual temperatures, especially as the reading is not necessarily that accurate.
The gauge is driven by a sensor mounted at a point that is often reported to be out of the hot water flow. Certainly it's taken from one point on just one of two cylinder heads (and I'm not suggesting it's easy or practical to take readings from various points on each cylinder head). Added to that, the fans are driven by the otter switch which will either be mounted in the swirl pot or radiator, meaning there's no direct correlation between the reading on the gauge and the fans starting/stopping.
'Standard' thermostats open at 74°C and 82°C so if the gauge was accurate and the thermostat was working properly it would be reasonable to assume that 'normal' temperature would be around 74°C or 82°C but this does not take account of the cooling effect of the heater matrix, which is independent of the thermostat. In very cold weather, at high cruising speeds, I don't think it would be unusual for the gauge to read just 60°C or 65°C. Similarly, in hot weather and/or standing traffic, a 100°C reading would not necessarily be out of the ordinary.
The key is to mentally note the various readings in varying conditions and only be concerned if they change.
The gauge is driven by a sensor mounted at a point that is often reported to be out of the hot water flow. Certainly it's taken from one point on just one of two cylinder heads (and I'm not suggesting it's easy or practical to take readings from various points on each cylinder head). Added to that, the fans are driven by the otter switch which will either be mounted in the swirl pot or radiator, meaning there's no direct correlation between the reading on the gauge and the fans starting/stopping.
'Standard' thermostats open at 74°C and 82°C so if the gauge was accurate and the thermostat was working properly it would be reasonable to assume that 'normal' temperature would be around 74°C or 82°C but this does not take account of the cooling effect of the heater matrix, which is independent of the thermostat. In very cold weather, at high cruising speeds, I don't think it would be unusual for the gauge to read just 60°C or 65°C. Similarly, in hot weather and/or standing traffic, a 100°C reading would not necessarily be out of the ordinary.
The key is to mentally note the various readings in varying conditions and only be concerned if they change.
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