My car has a 2.0 Duratec with a Polo radiator and 82º stat. When the weather is warm, there's no problem and the fan only kicks in when sitting
in traffic and keep termperature below 93º.
The problem I found is when the outside temp is below 10-15º, the car is operating at 75-78º when on the road, and I would like it to be al least over
80º.
I replaced the stat just in case but the behaviour doesn't change.
Is this normal?
Many thanks and sorry for my bad english 
Regards.
Due like the NASCAR boys and put a little tape on the grill (close off part of the radiator) people in the northern part of Canada have been doing it
for years in winter.
More to get heat from the engine for warmth, Volvo 544's had a chain under the dash you used to pull a screen up in front of the radiator on
cold days.
If the stat is shut taping over the grille won't affect anything other than heat loss from the block due to air flow through the bay.
I've got the same problem with a big multi core radiator and an 82 degree stat since I change to a low power Pinto
Thinking of going back to 88 degree stat on this engine
82 degree stat starts to open much earlier so seeing mid 70's is about right
A lot depends where you are measuring the temperature, the standard Duratec thermostat also opens when the flow pressure increases as the engine is
revved, you could try increasing the bypass flow to reduce flow pressure on the stat
Anywhere between 75 and 115c corresponds to "N" on most modern tintops because the tintop ECU processes the reading before sending it to the
dash.
The rating of the thermostat is the starts to open temperature, normal running temp would normally expected to be seesaw between 1 degree below to 1
degree above during normal motorway driving.
[Edited on 24/5/14 by britishtrident]
The mechanical Duratec stat opens at 85 degrees.
I know you have Megasquirt so not using ecu to control stat, but do you have the non ecu stat?
The one without electrical connectors.
quote:
Originally posted by coyoteboy
If the stat is shut taping over the grille won't affect anything other than heat loss from the block due to air flow through the bay.
None of my cars have bypass circuitry that actively cool the bypass water, it either goes to the heater matrix (which won't cool any differently
with more airflow into the rad), or it recirculates back into the block and reheats until it is hot enough to open the stat.
I guess if you have plumbed it without any other bypass route other than through the rad, and your bypass circuit is monstrously high flow, you might
see enough cooling to keep it cool at idle or slightly above. What hardware is in the bypass on these to cause grille airflow to cool it?
Bypass on Duratec doesn't flow through rad it just circulates around the block to speed up warm up times and thereby reduce emissions.
That's what I figured, no idea how blocking a rad will affect it then, other than affecting ambient air around the block as I mentioned.
If the bypass system is allowing too much flow thus not allowing the stat to reach opening temperature is it possible to fit a restrictor in the bypass? Try clamping the hose to see if restricting will raise the temperature but don't overdo it
Restrictions acting by-pass flow is not a good idea, bypass flow warms the bottom of the cylinders, prevents localised hot spots and ensures
the engine warms up quckly and evenly
The normal Duratec thermostat throttles back the bypass as the thermostat opens.
quote:
Originally posted by big-vee-twin
The mechanical Duratec stat opens at 85 degrees.
I know you have Megasquirt so not using ecu to control stat, but do you have the non ecu stat?
The one without electrical connectors.