Any 3.5EB F-150 Owners Out There

I have a 2017 F-150 3.5 EB with 28k on it, I have noticed my fans running quite a bit recently. After being on the interstate as soon as I exit I noticed the fans are on high. After a few minutes of driving 35-45 they cycle off. Even driving around town I have noticed the fans are on low at stop lights, this is in 50 degree temps with very few stop lights. I live in a rural area and outside of my neighborhood speeds are 45-55 on local roads. What im getting at is truck does not sit in stop and go traffic.

Today, I hooked up my scan gauge to monitor coolant temps and sure enough on the interstate running 70-75 the coolant temps climbed into the low 230s. This was after driving maybe 3-4 miles on the interstate. As soon as I began to exit the temps dropped almost instantly down to the low 200s, normal cruising it did not go above 210. As long as I stayed at a somewhat low speed the temps remained low. On my way back home on the interstate they shot back up into the 230s.

Has anyone had any overheating problems with their EB engines. Its not technically overheating, I am concerned since my fans are always running and the temps have been in the 50s and 60s. I plan to use my scan gauge on my next few trips so I can continue to monitor, especially on a long cruise on the interstate.

I have a feeling either there is a restriction flow in the radiator or the thermostat is not opening all the way. It sounds as if there is a circulation problem possibly in the cooling system. The truck is not using any coolant at all but the problem is getting worse as I am noticing my fans coming on more and more. I even deactivated my grill shutters thinking they were not opening fully and no change.

I spoke with the dealer and they said as long as the truck is not throwing any overheating codes there isnt much they can do at this point. Id rather fix this sooner than later as I use the truck to tow my car and id hate to be stranded somewhere. If its getting that warm with no load I have a feeling it will be hotter with a load behind it.

Any advice will be appreciated before I start shotgunning parts at this thing.

I have a ‘18 3.5Eco with 26k miles. I just drove from CO to TX without trailer and then back to Colorado while towing a car. Yes, my fans stay on more than the norm, however, I have 5* tuning and I believe they intentionally have the fans turning on more. Engine temps were perfectly fine. I should have thrown on my N-Gauge to see the actual temps. Doesn’t really answer your question but I wouldn’t be concerned. The setup and programming on the Eco’s is amazing and done just right IMO.


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Could crank the heat on max in the truck and see if that lowers it at all. I would try washing out the radiator, as you're in bug country I would guess.

cant say I even know when the fans come on in my 2012 and temp gauge doesnt move so havent paid any attention. I guess I'll hook up my tuner and see what it looks like.

Doesnt your truck have the little flaps in the grille that close at highway speed for aerodynamic/fuel mileage purposes? Mine is too old for that shit

There is a TSB for plugged heater cores from coolant deposits, and I believe they changed to the yellow the coolant for 2019-up.

Maybe worth a read just in case it manifests in the radiators?

My Dad’s Toyota was doing the same thing. Had me stumped. I put a thermostat in, fan clutch and he still was overheating on the highway. I figured it had to be a restricted radiator. I put a new one in and he had no issues after that.

it sounds like you have an issue. I would start with the radiator and a system flush

Happen to check the coolant level?

I had a '13 EB and had an Aeroforce gauge plugged into the service port. Coolant temps were 210ish and slightly higher when I was under boost. Near 240, failsafe "should" cut power. Mine had a failed water pump at 75k and fixed under warranty. Then a failed turbo coolant line o ring three months later that slowly bled coolant.

Tractorman said:

Could crank the heat on max in the truck and see if that lowers it at all. I would try washing out the radiator, as you're in bug country I would guess.

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I will take a look at the radiaor, from what I can see there really isnt to many bugs on it.

DSG2003Mach1 said:

I guess I'll hook up my tuner and see what it looks like.

Doesnt your truck have the little flaps in the grille that close at highway speed for aerodynamic/fuel mileage purposes? Mine is too old for that shit

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Please post up what your numbers are once you hook up your tuner. Yes my truck has the active grill shutters but I unplugged them so they are inoperable. No change to coolant temps.

M91196 said:

There is a TSB for plugged heater cores from coolant deposits, and I believe they changed to the yellow the coolant for 2019-up.

Maybe worth a read just in case it manifests in the radiators?

View attachment 1629533

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Thanks for sharing, I have no issues with my heat but now you have me thinking there could be a build up in the radiator due to the coolant.

Crimson2v said:

My Dad’s Toyota was doing the same thing. Had me stumped. I put a thermostat in, fan clutch and he still was overheating on the highway. I figured it had to be a restricted radiator. I put a new one in and he had no issues after that.

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After doing a few searches I do believe it is a radiator issue. Now the question is do I wait until I actually overheat so the dealer will replace or just pony up a couple hundred and swap it myself. Thanks for sharing.

me32 said:

Happen to check the coolant level?

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No change to coolant level, in 28k miles level remains full.

Riddick said:

I will take a look at the radiaor, from what I can see there really isnt to many bugs on it.



Please post up what your numbers are once you hook up your tuner. Yes my truck has the active grill shutters but I unplugged them so they are inoperable. No change to coolant temps.



Thanks for sharing, I have no issues with my heat but now you have me thinking there could be a build up in the radiator due to the coolant.





After doing a few searches I do believe it is a radiator issue. Now the question is do I wait until I actually overheat so the dealer will replace or just pony up a couple hundred and swap it myself. Thanks for sharing.

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Based on the TSB, couldn't you just take a tech for a drive with there equipment and show them the issue?

You shouldn’t have to have codes in order for the tech to do his job properly. In the WSM they have symptom charts to go off of based on customer concerns. If it is under warranty I wouldn’t pay a damn dime to fix the problem. I can’t stand dealers that do this crap.

Motorcraft has coolant system cleaners you can run through it.

Also, even though it is cool out, are you running your ac at all? The fan will kick on a lot to try to get air through the condenser.

Riddick said:

Please post up what your numbers are once you hook up your tuner. Yes my truck has the active grill shutters but I unplugged them so they are inoperable. No change to coolant temps.

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Both on my 75 degree drive to work and 85 degree drive home I never saw over 209. 209 was ac on low and a WOT pull to merge onto an expressway. Cruising anywhere from 50-70mph it was usually around 203, this includes stop and go at lights and on the expressway. 2012 truck, 87 tune is it for anything performance related

DSG2003Mach1 said:

Both on my 75 degree drive to work and 85 degree drive home I never saw over 209. 209 was ac on low and a WOT pull to merge onto an expressway. Cruising anywhere from 50-70mph it was usually around 203, this includes stop and go at lights and on the expressway. 2012 truck, 87 tune is it for anything performance related

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Thanks for sharing, I am definitely a little higher than that. Its in the mid 60s here and I just went out for a cruise on the highway. Temps never rose past 226 and they pretty much held that the entire time cruising at 75 mph. As soon as I exited the highway and stopped the temps came down to 214. Cruising at 45-50 the rest of the way home temps held steady at 215-220. Fans were on low entire time.

I still think I have a problem so I will try to get an appointment with the dealer if they are open and drop it off. Hopefully I do not have any issues.

Pics below are from cruising at 75 and the second one is after I exited the highway and stopped immediately.

IMG_20200325_122752115 by Leonard Riddick, on Flickr

IMG_20200325_123841753 by Leonard Riddick, on Flickr

Riddick said:

Thanks for sharing, I am definitely a little higher than that. Its in the mid 60s here and I just went out for a cruise on the highway. Temps never rose past 226 and they pretty much held that the entire time cruising at 75 mph. As soon as I exited the highway and stopped the temps came down to 214. Cruising at 45-50 the rest of the way home temps held steady at 215-220. Fans were on low entire time.

I still think I have a problem so I will try to get an appointment with the dealer if they are open and drop it off. Hopefully I do not have any issues.

Pics below are from cruising at 75 and the second one is after I exited the highway and stopped immediately.

View attachment 1630279IMG_20200325_122752115 by Leonard Riddick, on Flickr

View attachment 1630280IMG_20200325_123841753 by Leonard Riddick, on Flickr

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ya they need to look at it, my outside temps were 20 degrees higher yet my off highway temps were still over 10 degrees lower and highway temps over 20 degrees lower

I made an appointment and took my truck in yesterday. The dealer states when the tech drove the truck the temps never rose above 210 and everything is operating as it should.

When I first bought the truck the first thing I did was removed the grill shutters for the intercooler. Ford has these programmed to open only under WOT or extremely high IATs. The tech noticed mine were missing and says if I am running hotter its because I removed them, such BS. All I am doing is allowing the AIR to AIR intercooler to have air going over it all time, how this causes my truck to run hotter I will never know.

I guess ill be doing some more troubleshooting on my own. Plan is to use a IR thermometer and compare inlet and outlet temps on the radiator. Also, I will use HP tuners and pull the stock tune and see when the fans are programmed to come on. I am guessing its 220-225, since mine are always on even with the a/c off.

Riddick said:

I made an appointment and took my truck in yesterday. The dealer states when the tech drove the truck the temps never rose above 210 and everything is operating as it should.

When I first bought the truck the first thing I did was removed the grill shutters for the intercooler. Ford has these programmed to open only under WOT or extremely high IATs. The tech noticed mine were missing and says if I am running hotter its because I removed them, such BS. All I am doing is allowing the AIR to AIR intercooler to have air going over it all time, how this causes my truck to run hotter I will never know.

I guess ill be doing some more troubleshooting on my own. Plan is to use a IR thermometer and compare inlet and outlet temps on the radiator. Also, I will use HP tuners and pull the stock tune and see when the fans are programmed to come on. I am guessing its 220-225, since mine are always on even with the a/c off.

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Your making a big mistake, when you have a problem its needs to be brought to them stock. You as the owner need to show them and drive it with the tech in the way you drive it to show them. Otherwise your dealing with a needle in a hey stack.

Fixed the issue. It turns out the factory thermostats in the 2017 3.5s is a 195 and does not fully open until 217 degrees. In 2018 and up they switched back to a 185, not sure why the 2017s are different.

I had the factory 180 thermostat from my Mustang laying around, turns out its a direct fit so I installed it. I went out for a 20 mile drive and temps never rose past 200 and the fans never came on one time. For the most part temps stayed in the 190-200 range which I am comfortable with. Previously, my cruising temps were in the low 230s. Maybe I had a faulty thermostat to begin with...... who knows.

I'm rather disappointed in Ford for not seeing this and blaming it on me by removing my intercooler grill shutters. Only downside to this is my truck ate my 1/4 in. extension, i've had it for nearly 20 years........

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