I got a tuner from stage 3 motorsports and put on a 5star tune (93 octane tow/perf) on a 2017 3.5L eco.

With the tune, it seems like the fans in the radiator are running full speed all the time, whether it's sitting there idle or driving - It's loud enough that the wife asked what the noise was.

Is that normal for a tune? I've never seen any mention of this when reading about tunes.

 

Yes, completely normal. If you install a 170* thermostat, the fans wont cycle as much as the engine will be below their new activation threshold more frequently. To give you a specific answer, the more aggressive timing and boost settings require lower cylinder head temperatures for increased safety...hence the lower fan activation threshold.

 

Thanks. I noticed the livernois packages included a thermostat (160* or 165* if I remember right). Would installing something like the full race intercooler cool things down and lessen this? I was kind of worried about what this would do to the longevity of the fans, or even the engine if this means it's running a lot hotter (watching the temp gauges, seemed like it was maintaining just slightly higher temps than stock).

 

If you live somewhere you need the heater most of the time when driving in the winter, don't lower your thermostat opening temp by much !

 

I've had 5* 91 P/T tune on a 5.0, went to MPT 93PRX on it. Now I'm using MPT 93 PRX on my 3.5. None of those tunes on either engine had the fans running with OEM thermostat, in summer or winter. If those fans are running, I've never heard them.
Maybe call 5* and talk to them, they're pretty easy to talk to. Actually call them on a phone.

 

I wouldn't use a 160, that's a bit too low. The Reische 170 is the ideal temperature and uses the same t-stat design as factory with the proper bypass. I just installed one, and my fans rarely cycle now, with normal operating temperatures in the low 190's. My tuner had the fans set to 100% at 200 degrees, and I think 50% at 190 degrees, so the new t-stat means I rarely hear the fans. My 5.0 had a factory 190* t-stat, but I think your ecoboost uses a 180*...so a 170 might be just enough to keep your fans from cycling.

A aftermarket intercooler will not effect the fans cycling, but isn't a bad upgrade if performance is your goal. Otherwise stock is fine.

 

The threshold temperatures for different fan speeds are configurable. Ask the seller of your tunes to set them a little higher and your fine. MPT did that for me, was a matter of minutes at no extra cost.

 

This. I've got a 2018 3.5 with 5 star 93 perf and perf/tow. Fans rarely come on unless I am having fun. Just fill out the tune cal request. Easy fix.

 

OK - this is all new to me, so sorry if this seems obvious. If I replace the thermostat with one that is lower, that will keep the engine temp lower, reducing the *need* for the fans to run? What is the downside of this (why did Ford put one that is 180 degrees if 170 is better?) Does it make it warm up slower, passenger heat is reduced, etc? One of the possible downsides of the full race intercooler upgrade is that I have to remove the shudders, which I expect would make heating up a cold engine slower, so that's something I'm already considering.

If I just ask the tuner to raise the thresholds, seems like that is just telling it to run the engine hotter to avoid the fan noise, which sounds like it would have negative engine life implications. Is there a way to see what they have it set to (say, in the tuner device?), or do I have to ask to know?

As for the intercooler upgrade, I'm really looking for that to make room for a hidden winch in the bumper. The possible performance improvement is a definite plus, but secondary. I figured if it's sending cooler air in, that might have an effect on engine temp, but makes sense that it wouldn't be that much if any,

How difficult is it to change the thermostat on these engines? Just looked at a video on it, and doesn't seem too bad.