tomb1269

Looking for the guys out their that work for and knoa the Fords very well. I ma curious how the Emergency Cooling Mode works i.e. limp mode, particularly on the 2005 5.4L. It is my understanding that the mode is triggered by the coolant level sensor, but what I'd like to explore is what would happen if you tricked the coolant sensor in to thinking the coolant was low, would it cause damage to the engine to run any length of time? From what I have read it cycles thru the cylinders shutting off fuel to allow outside air in thru the valves as well as decrease the amount heat produced by the engine to keep you from burning up the motor. My thought is that this could provide a fuel savings mode when power is not needed by ticking the level sensor? If you think about it, if you drop only 1 cylinder each complete cycle (cycle being each cylinder firing once) you would decrease fuel consumption by 12.5%. If it were 2 per cycle thats 25%, enough to bump mileage from 15mpg to 18+mpg or 20 to 25mpg....
Thoughts.........

picaflor

http://media.ford.com/article_displa...rticle_id=2600

Fail Safe Cooling System

What it is: A Fail-Safe Cooling System allows a vehicle to be driven under limited power in the event that engine coolant is lost. In case of a ruptured hose, the engine operates in an emergency mode with limited power for driving a short distance (10-50 miles depending on the system). This eliminates the cost and inconvenience of having the vehicle towed to a service station and does not leave the customer stranded. How it works: If the coolant level sensor reads below a critical amount, the engine computer module switches the engine to an emergency limp-home mode, in which only half the cylinders get fuel. With only half the cylinders firing, the engine generates much less heat because it is operating at low power. The cylinders alternate between even- and odd-firing pistons. The engine is able to move the vehicle at moderate speeds (up to about 50 mph). Customer benefit: Customer is not stranded in case of coolant system failure. Ford status: Standard on many North American vehicles, including F-Series trucks and the Lincoln LS.

picaflor

so... not good for highway (more than 50mph usually... and Overdrive is for that), maybe an option for stuck in traffic... but for stuck in traffic situations... maybe a flinstone solution like an opening in the floor will be better...

tomb1269

My legs are not long enough.....

tdm156

Sounds kinda like the AFM or active fuel management on some GM products.