An Engine that won’t get Hot.

[blue 54]

Hi chaps. Just throwing this out there for ideas. 
my Bentley engine does not get hot.  It gets warm but not hot. 
so done the usual new stat (yes original equipment ) even run it without the viscous fan until the electric ones cut in 

still the car only gets warm - yes I know logic says if the main electric ones cut in and out then the engine (coolant) MUST be up to temp but you can still hold any hose and it’s only Luke warm. 

Yes the electric fan switch might be kicking in to soon -they NEVER run with viscous connected (there there for the condenser-with a back up facility for engine temp) 

but I just can’t get the engine up to running temp. 
so any ideas. ???  

[IanS 73]

It would not be the first replacement thermostat that I have come accross that opened early.

Have you tested in a pan of water on the stove to see what temperature it actually starts to open at.

Replacement OEM stat for my Saab about 5 years ago started opening at 52 degrees which was worse than the dud one at 58 degrees. Spec reads 98 degrees

[alantoon 123]

Do what my Dad used to do in the 50s/60s with his old Morris Minor, every winter he used to block off half of the radiator with a sheet of cardboard, no fancy radiator muffs for him.

[blue 54]

Hi.  Tried the stat thing this is it’s third. !!!   

Yer done the blocking off half the rad -used a sheet of Perspex 

it just runs cool !!  

[Peter Bell 119]

Are you sure the gauge is correct? Can you see water flowing in the rad?

[alantoon 123]

If the water is flowing in the system it seems to me that it must be by-passing the thermostat somehow, if not the water would heat up eventually even if the engine was running cool.

[blue 54]

Bentley gauges are quite accurate but it’s not the gauge I’m worried about- never thought of them as anything more then a slight indication of engine temp 

now with regards to bypassing  the stat I put a second stat in the top hose effectively blocking off the rad -no difference 

the engine only runs Luke warm- you can leave it running an hour and still hold the top hose 
the side effect is poor heater 

but logic says it MUST get hot unless it has the most efficient heater matrix in the automotive world.

[IanS 73]

The heat has to go somewhere.

Normally only 2 places the radiator or the heater.

Could the aircon be going full blast to drain the heat from the heater?