Land Rover and Range Rover Forum banner

1 - 12 of 12 Posts

·
member
Joined
·
1,818 Posts
Discussion Starter #1 (Edited)
So here goes my 2 cents on these Thermostats and temps.

The original Thermostat that you get on a D2 seems to be the 187F. The 192F is for cold climate only.

My Grey 180F Thermostat runs on highway between 184-188F. On slow roads under 35mph 190-193F. It idles at long lights/ traffic 195-198F. Hottest I have seen it in stoped traffic 200-202F then it will go back to 197-195F. This is with a 20 year old cooling system I assume; original Water pump, Fan Clutch, Radiator and AC Fan Condenser (Fan Clutch, AC Fan Condenser, water pump I plan to replace).

So if you have a 187F thermostat (the standard) then your temperatures Should be 193-195 on highway, 195-200F in Slow roads and 200-208F in stop lights and stuck in traffic. Highest temps should 210F to 212F.

From watching the Scanguage with the 180F Thermostat. The highest and most common highway temps seem to be 188F, highest at stop and go 195F, Highest temp on long red lights 198F and highest it has peaked 202F.

Dave
 

·
Registered
Joined
·
5,726 Posts
So here goes my 2 cents on these Thermostats and temps.

The original Thermostat that you get on a D2 seems to be the 187F. The 192F is for cold climate only.

My Grey 180F Thermostat runs on highway between 184-188F. On slow roads under 35mph 190-193F. It idles at long lights/ traffic 195-198F. Hottest I have seen it in stoped traffic 200-202F then it will go back to 197-195F. This is with a 20 year old cooling system I assume; original Water pump, Fan Clutch, Radiator and AC Fan Condenser (Fan Clutch, AC Fan Condenser, water pump I plan to replace).

So if you have a 187F thermostat (the standard) then your temperatures Should be 193-195 on highway, 195-200F in Slow roads and 200-208F in stop lights and stuck in traffic. Highest temps should 210F to 212F.

From watching the Scanguage with the 180F Thermostat. The highest and most common highway temps seem to be 188F, highest at stop and go 195F, Highest temp on long red lights 198F and highest it has peaked 202F.

Dave
I am not sure what point you are trying to make.

Also the majority of D2's came with 180F thermostats from the factory.
 

·
member
Joined
·
1,818 Posts
Discussion Starter #3
I am not sure what point you are trying to make.

Also the majority of D2's came with 180F thermostats from the factory.
No, they did not.
in the US they came with standard 187F or for cold climate 192F. Hot climate Saudi Arabia and I imagined Australia 180F.
Dave
 

·
Super Moderator
Joined
·
2,148 Posts
That was my understanding too Dave.

Your temps. Seem reasonable IMO
 

·
Registered
Joined
·
5,726 Posts
No, they did not.
in the US they came with standard 187F or for cold climate 192F. Hot climate Saudi Arabia and I imagined Australia 180F.
Dave
The early ones came out with the hotter thermostats. They then realised that a lot of the head gasket and slipped liner issues related to the running temp of the motor. So until the worked it out properly they put in the middle temp thermostats. The final solution was the 180F thermostats. So all the later D2's had the 180F thermostats. It had nothing to do with hot or cold climates. It was simply a matter of when they were produced.
 

·
Super Moderator
Joined
·
2,148 Posts
Kind of a moot point IMO.
Arguing early or late production really has no point, especially not knowing what model year truck Dave has.
Again just an opinion but Most often head gaskets will fail from poor maintenance and or an overheat condition, not just a 190 thermostat.
Pretty sure you have expressed that from your experience liners rarely leak /slip Ian. (Can find if you like) but now you state that it was the reasoning for Land Rover installing lower temp thermostats?

Not sure what your point is Dave.
Again 180deg stat is the way to go and the temps posted are acceptable.
 

·
Registered
Joined
·
5,726 Posts
Kind of a moot point IMO.
Arguing early or late production really has no point, especially not knowing what model year truck Dave has.
Again just an opinion but Most often head gaskets will fail from poor maintenance and or an overheat condition, not just a 190 thermostat.
Pretty sure you have expressed that from your experience liners rarely leak /slip Ian. (Can find if you like) but now you state that it was the reasoning for Land Rover installing lower temp thermostats?

Not sure what your point is Dave.
Again 180deg stat is the way to go and the temps posted are acceptable.
As Per the RAVE CD for US vehicles Thermostat operating temperature: ⇒ Initial opening 82C (179F) ⇒ Fully open 96C (204F)

I am not sure why people think that putting a 180F (179F) thermostat in their D2 is some type of modification.
 

·
member
Joined
·
1,818 Posts
Discussion Starter #8
As Per the RAVE CD for US vehicles Thermostat operating temperature: ⇒ Initial opening 82C (179F) ⇒ Fully open 96C (204F)

I am not sure why people think that putting a 180F (179F) thermostat in their D2 is some type of modification.
Not sure how that is possible the Thermostat that was on my D2 was idling at 210F, the 180F I put in it idles at 198F
Dave
 

·
Registered
Joined
·
5,726 Posts
Not sure how that is possible the Thermostat that was on my D2 was idling at 210F, the 180F I put in it idles at 198F
Dave
As I have tried to explain previously, they changed the specification for the part over the life of the D2. A 179F thermostat is now what is specified to be fitted to all D2's even though they may have left the factory with a hotter one in it. Effectively the hotter thermostats have been superseded by the 179F one.
 

·
member
Joined
·
1,818 Posts
Discussion Starter #10
As I have tried to explain previously, they changed the specification for the part over the life of the D2. A 179F thermostat is now what is specified to be fitted to all D2's even though they may have left the factory with a hotter one in it. Effectively the hotter thermostats have been superseded by the 179F one.
OK Ian.
So now if the 180F (179F) Thermostat opens at 179F if you see your temps rise up to 204F it means the cooling system is working fine? Anything over 204F on the 180F thermostat means its overheating or something in the cooling systems is not working right? (Radiator, Fan Clutch, AC Fan Condenser etc.)
Thanks,
Dave
 

·
Registered
Joined
·
5,726 Posts
OK Ian.
So now if the 180F (179F) Thermostat opens at 179F if you see your temps rise up to 204F it means the cooling system is working fine? Anything over 204F on the 180F thermostat means its overheating or something in the cooling systems is not working right? (Radiator, Fan Clutch, AC Fan Condenser etc.)
Thanks,
Dave
The thermostat is fully open at 204F and is therefore making the maximum use of the radiator. I am not sure how you make the jump to anything above this means something is wrong. My Rangie has 180F thermostat and regularly runs above 204F when I am pulling a trailer with a car on it on a hot day with the air-con running. It does not mean that there is anything wrong with the cooling system.
 

·
member
Joined
·
1,818 Posts
Discussion Starter #12
The thermostat is fully open at 204F and is therefore making the maximum use of the radiator. I am not sure how you make the jump to anything above this means something is wrong. My Rangie has 180F thermostat and regularly runs above 204F when I am pulling a trailer with a car on it on a hot day with the air-con running. It does not mean that there is anything wrong with the cooling system.
So when do you know you have surpassed the cooling capability of the system? It would seem that at 204F to me it would be the extend of the cooling of the system, if at that point you have all the fans running cooling the Antifreeze/coolant mix and the thermostat fully opened. I understand that the aux/AC Fan comes on at 213F if you are not using the AC, but that was when they first had the 192F Thermostat. But with this lower temp thermostat those numbers should have changed by about 10F. So the AC Fan should be re-programed to come on at 203/205F or so.
Dave
 
1 - 12 of 12 Posts
Top