Ford EcoBoost 170 degree thermostat Reische Performance

Messages
5,707
Location
North Texas
Not ford related but back when i had the Toyota 3.4L. You could take the thermostat and rotated it 180 degrees. There's a jiggle valve on the thermostat. It would drop operating temps between 7-8 degrees. They called it the jiggle valve mod.
 
Messages
3,029
Location
USA
Originally Posted by ARB1977
You could take the thermostat and rotated it 180 degrees... They called it the jiggle valve mod.
That makes absolutely no sense. The jiggle valve is to let the air bubble out of the engine while you're filling the system. So it should be at the top in designs where the thermostat sits on edge vertically. Once full and running, any water that goes through the jiggle valve would be the same regardless of position.
 
Messages
5,707
Location
North Texas
Originally Posted by mk378
Originally Posted by ARB1977
You could take the thermostat and rotated it 180 degrees... They called it the jiggle valve mod.
That makes absolutely no sense. The jiggle valve is to let the air bubble out of the engine while you're filling the system. So it should be at the top in designs where the thermostat sits on edge vertically. Once full and running, any water that goes through the jiggle valve would be the same regardless of position.
On the Toyota 3.4L they came installed from the factory with the valve at the bottom even though it says to install it at the top.Yes I did a OBD check before and after and saw a 6-8 degree drop.
 

Navi

Thread starter
Messages
467
Location
NYC
This is true. The only exact temperature the Navigator shows is the transmission temp...The actual coolant temp is a digital gauge with no.exact reading. I have mobile forscan and a wireless plug. The active shutters are for fuel economy. I read it might have something to do wih the CAC but I think its mainly to squeeze out every bit of mpg. Will update thread in the future.
 

Navi

Thread starter
Messages
467
Location
NYC
Been a while since I updated this thread. This is the highest temperature hit so far. Most of the time stays under 200. The owners manual says that is the transmission fluid temperature.

The conditions were the following:
- 94 degrees outside
- Stop and go traffic in Hoboken NJ
- Radiator grille slats disconnected and open all the time
- 170 degree thermometer installed

Usually its difficult to get it over 200 with this setup but today was the hottest day so far.

Before these mods under same conditions it would hit 230!

20200720_191545.jpg
 
Messages
4,559
Location
Decatur AL USA
Originally Posted by RhondaHonda
Does your Navigator Show oil temp like the newer F-150s do? I'd be curious what the temps were before and after the thermostat swap.
I have a 2019 F150 with the high output 3.5 Ecoboost. The only oil temperature it shows is the transmission oil temperature. It doesn't show engine oil temp. In fact, unless you have downloaded Forscan, and modified the ECM programing a bit, you won't even see actual trans oil temps, until the transmission gets dangerously hot. Using Forscan, you can have the trans temps and coolant temps digitally displayed above the analog gauges all the time. I did this mod on my truck. I also have a Reische 170 thermostat, but have yet to install it. I was seeing 220 degree coolant temps routinely in normal driving. Since unplugging the shutters which regulate air flow through the radiator, coolant temps are 10 to 15 degrees cooler. Why the shutters are there other than to keep the engine artificially hot is unknown. When connected, the shutters only open under acceleration, and close on cruise or low throttle. My truck has a 195 degree thermostat as OEM. The reason I've not yet installed the 170 T-stat is I cannot find what triggers the Ecoboost to switch from open loop operation after startup, to closed loop. On most vehicles, coolant temperature reaching a certain point is that trigger. Older Fords made that switch based on time after start only, but I can't find anything about the later models. If the engine stays in open loop continuously, mileage will take a serious hit.

No you don't. All you have to do is put it in Engineering Mode. Although it's actually an inferred coolant temp. It actually only has a Cylinder Head Temp Sensor and a lookup table for the Inferred Coolant Temp. Trans Temp is also in there.
 

Navi

Thread starter
Messages
467
Location
NYC
So far the experiment with the 170 degree thermostat and Active Grill shutters disconnected worked very well. When the Active Grill shutters are connected and the computer closes them then the temperature seems to reach as high as 217 degrees. I have no idea why or when the shutters close. Someone said the shutters open when the AC is on but that is not my observation. My observation is they seem to close at random whenever they want to but when I put the AC on it obviously doesnt open them.

However, it worked too well and while I didnt do exacting MPG measuring my observation was my fuel economy took a hit like the engine was in continual warmup mode. When the shutters were connected the temperature rose a bit and the mpg got better.

So I have ordered a 180 degree thermostat and will install that one and disconnect the shutters to see if that has any difference. I noted with the shutters disconnected and the 170 degree installed the vehicle temperature operating range seemed to be 170-190 and it seemed almost impossible to push over 200. The stock cooling system is actually quite good but when the shutters are closed the temperature will climb.

If that doesnt improve the gas mileage by raising the temperature then I will simply intall the stock 195 degree thermostat and leave the shutters open.

Take note...if you race, live in Arizona where the temperature gets to 120+ degrees or tow heavy the 170 degree thermostat and disconnecting the shutters is a MUST. However, for what Im using the vehicle for I think I will go with the 180 and will let everyone know how it goes...might have to reinstall the 195..

Photos are of 180 degree thermostat. I always order thermostats from the dealer because I want to be 100% sure Im not getting a fraudulent copy of the thermostat. There are lots of copies everything which look like the original, but dont work like the original.

180thermostat.JPG
180thermo2.jpg
 

Navi

Thread starter
Messages
467
Location
NYC
20200815_160411.jpg


This 170 degree thermostat with active grille shutters worked too well bringing temperatures down to the point where the fuel economy was horrible. Re-enabling the shutters and again I had temperature spikes to 220 degrees.

The 180 degree thermostat with active grille shutters disabled was perfect. No temperature spikes. Temperatures seemed to range from 188 to 201 degrees. Just hot enough so the engine isnt in warmup mode zapping fuel efficiency but not hot to the point where reliability is effected.

The stock setup I saw temps climb to 225 degrees. Ive always been told temps over 200 degrees seriously degrade atf and severely effect trans life...and my first 10R80 lasted 70000 miles...thus my interest in this modification.

The 170 degree thermostat with shutters disabled is great for track racing, heavy towing and outside temps over 90 degrees like in Arizona. The 180 degree is ideal for regular driving. The stock setup is good for colder climates like Canada. For someone like myself this thermostat is ideal. Keep in mind 180 degree thermostat/no shutters was the original setup on the initial F150 Ecoboosts but in later models they went with 195 degree thermostat/shutters.

Above picture is the 180 degree thermostat.
 
Top