[paul01]

Hi,
yes i use a thermostat that opens at 79°C and i am happy with this one.

But the 74°C that Mikael mentioned above is ok. Here ist my old research:

Workshop manual also will show a 74°C one:

The oil thermostat opens at 80°C. So the 79°C water thermostat is the best for me.

Does anybody drives his car with oil or water under 80°C ? I dont think so.

E.g. if you have a watertemp of 85° the thermostat is fully open. Then it doesnt matter wich one you use.

It is not possible to run cooler with a thermostat that opens earlier. It makes only a difference while warming up. And downhill.

Paul

 

[paul01]

Bruce, i have to look to that later today.

But if you have the 74°C type then no need to change. It will not be better with 79°, but also not worse.

The game is this:

If you have a temp problem or you want be in the range 80°C...90°C the thermostat has to open at the lowest temp or a few degrees below (not much). Or simply use the lamborghini values.

Next thing is to be sure that the thermostat opens completely and closes also.
Also no air in the system (old diablos have automatic system) and water pump working.

All the other things: the outer water circle. Most important is the area with the both radiators. Best is if this area is all the time cooler than the thermostat open temp.

Both fans running ?
Also ok is if the fans stop working many degrees below the thermostat open temp. They should do all for keeping the temp difference outer circle/inner circle.

Paul

 

[paul01]

Hi,

don´t know NAPA parts.

I use this one : Behr TX 97 79D

see also: https://www.lamborghini-talk.com/vbforum/f45/odd-coolant-temperature-behavior-184210/

Paul

 

[paul01]

no thermostat...look here Odd coolant temperature behavior

 

[paul01]

Never run these cars without thermostat

-> right