Coolant temperature has never run so low.
#31
Race Director
Thread Starter
The low temp unit opens sooner, and becomes fully open faster. The fully open faster part is why it can reduce operating temperatures, as it creates more cooling volume, being fully open.
These have been tested in temperatures below -20F before they were ever sold to the public, over a decade ago. The units are proven- every engine I build receives one. This includes units fitted to vehicles with my engine in Canada. About 1/3 of our work is Canadian, about 1/2 of those are C4s and driven year round.
The stock temperature thermostat had considerations when meeting the tests set forth by Federal Emissions Regulations. The engine needed the extra cooling system temperature to help keep the engine hotter for the "shed test" portion of the certifications.
Lots goes into these vehicles aside from what works best for the engine.
These have been tested in temperatures below -20F before they were ever sold to the public, over a decade ago. The units are proven- every engine I build receives one. This includes units fitted to vehicles with my engine in Canada. About 1/3 of our work is Canadian, about 1/2 of those are C4s and driven year round.
The stock temperature thermostat had considerations when meeting the tests set forth by Federal Emissions Regulations. The engine needed the extra cooling system temperature to help keep the engine hotter for the "shed test" portion of the certifications.
Lots goes into these vehicles aside from what works best for the engine.
Thanks Jake. Your explanation makes sense. Appreciate your input.
#32
Rennlist Member
Might be time for me to install one of these puppies...or at least clean my radiators.
#34
Rennlist Member
#35
Racer
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Same conditions, other car. Sitting in traffic, not going anywhere. Check the oil pressure as well, am running standard Mobil-1 oil. This is with rads cleaned, new airco condensors, fans running properly, new LTT, waterpump and coolant flush. 1998 C2 Coupe manual. Temperature indication earlier was like yours but then also one fan did not run in low speed mode due to a badly mounted relay.
If I'd do a bit more driving to thoroughly warm up the car I would expect the oil pressure to drop a bit to 1.8-2.0 bar.
If I'd do a bit more driving to thoroughly warm up the car I would expect the oil pressure to drop a bit to 1.8-2.0 bar.
Last edited by Volkert; 07-21-2017 at 04:34 PM.
#36
Rennlist Member
All those look normal to me. BTW, I tend to believe that the 2nd mark on the temperature display is around 110C.
#38
Rennlist Member
It was -10F (-23C) today on cold start. After driving on the freeway for about 1/2 hour, my engine temps never got above 86C (187F). In fact, when I had some open road after the car was fully warmed, I went through some gears at high RPMs and saw my temps drop a few degrees (83C). To my knowledge, I have the stock thermostat. Is there something wrong with my thermostat, or do all 996s behave this way due to extreme cold air cooling the engine down significantly?
#39
What you see happening is that upon promptly changing the rpm to a higher range the water pump spins faster which causes a sudden increased flow of much colder water from the radiators mixed with the hot coolant so more cold water enters the engine. Hence the sudden drop in temperature you see. After a while the thermostat readjusts to this new temperatures and finds a new 'equilibrium'. This new steady state could be some degrees off compared to befor as the thermostat does not have a linear range of operation.
My coolant temperature reading once the engine is fully warmed up is 81-82°C (steady state) independent from ambient temperatures (-5°C or 30°C it does not make a significant difference).
Of course it deviates from this equilibrium point some degrees depending on the way and how hard the car is driven, i.e. fast changing rpm's and driving speeds. Stop and go in summer will make temperature rise to 85-90°C but I do not consider this as a normal steady state condition as the water pump at these low rpm hardly pumps water and there is also hardly any driving wind for cooling. it always s around this temp.
To me any coolant temp between 80-90°C is totally fine. The lower the better even! The reading is indicative as in some parts of the engine temperatures can be considerably higher.
My coolant temperature reading once the engine is fully warmed up is 81-82°C (steady state) independent from ambient temperatures (-5°C or 30°C it does not make a significant difference).
Of course it deviates from this equilibrium point some degrees depending on the way and how hard the car is driven, i.e. fast changing rpm's and driving speeds. Stop and go in summer will make temperature rise to 85-90°C but I do not consider this as a normal steady state condition as the water pump at these low rpm hardly pumps water and there is also hardly any driving wind for cooling. it always s around this temp.
To me any coolant temp between 80-90°C is totally fine. The lower the better even! The reading is indicative as in some parts of the engine temperatures can be considerably higher.