RawGtPower

well i figured that i would replace my 180 degree thermostat with 160 degree to hopefully cure my high temp problem. is this going to be risky going that low, or will i be fine. im also getting another electic fan that i can flip on and off in stop and go traffic

mcfomco

The 160 thermosat will not allow the engine to reach the required 180 to switch the eec to closed loop.

RawGtPower

oh.. so i shouldnt do it.. Whats that mean, switch to close loop

mcfomco

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86HOGT

Yeah the coolant temp needs to be 178 degrees to achieve closed loop.

PX429

Can anyone explain "closed loop" in PLAIN English?

86HOGT

There's two loops or stragedies that the computer uses to calculate fuel delivery. Open loop is when the computer uses pre programmed fuel and spark curves while the engine is warming up. When it hits that certain temperature the computer now looks at the O2 sensors, MAF, and other sensors to calculate fuel delivery.

TwotoneVert

Basically, what it means, if your engine cant get to operating temperature, it will run very rich all the time, similar to having a choke stuck closed on a carbed engine. This will cause excessive build up of crap in your exhaust and other componets that will start to foul on you. You can change to a 160, if you retune the computer to see that as the operating temp, but why would you? I think, from what I understand, closed loop is when the t-stat opens, the computer sees that temp and adjusts the fuel ratio to match accordingly, if the loop is open, the computer is waiting on the temp to rise, and it will continue to dump more fuel than needed into the system, thinking the car is still trying to warm up. Clear as mud?

mcfomco

I give a link to a website that Has alot of information on this and people are to damn lazy to check it out.

vristang

I think most guys are looking for a link directly to OL/CL info.



I question the 178F trigger temp, as I have not been able to find the setting myself in the ford .bin file, (using a tweecer).

WOT is also open loop.


My question is what is your coolant temp, and how are you measuring it?
Your coolant temps should be between 180F and 205F.
If you are in a particularly hot part of the country, then a 160F stat may be the only way you can keep your coolant temps down.

What is the rest of your cooling system like?
Pump
Rad
last cooling system flush
age of coolant
coolant mix

jason