J_procyshen

Hoping the dealer can get this addressed it’s booked in for Tuesday.

Does this TSB apply to the 3.5 Ecoboost aswell?

boosted150

Honestly I'm not sure on that one. I would call the Kat's company just to be sure. I forgot the EB has a plastic pan. My 5.0 is still a steel pan.

boosted150

The TSB I posted does not apply to either Ecoboost engine, just the N/A 3.5 and 5.0. I don't have access to all of the TSBs but I have to imagine that this issue is not just limited to these engines. I read on another post that a 3.5 EB owner was experiencing the same problems but the fix was different as it utilized the same coolant as before. probably because the turbos are water cooled

IGWTAOWT

Hesitant to start new thread for this, seems my question might fit here...

Can use of block heater cause a thermostat to get stuck open? Are the components in close enough proximity for this to happen? (2014 3.5L ecoboost),

Have noticed decreasing ability to hit normal temp on engine in a timely manner, with corresponding lack of heat through core. This year worse than last - again. Most obvious thing to check/replace is thermostat. But my question suggests if I replace thermostat then continue using block heater I might be causing my own problem. We routinely spend consecutive months with -30F as a daily high, usually with a week at -40F thrown in for good measure. Safe to call the entire winter average temp -20F (daytime highs). So not using the block heater seems like I'd be asking a lot in terms of not expecting excess wear in the close tolerance parts until they get somewhere close to operating temp. (Notice I place my motor ahead of my personal comfort) Then there's that too. When I've already run block heater for 2.5 to 3 hours, then started and ran the truck for 15 minutes, and still mount up and freeze the *** off most of the way to work, well it's not really why I got the vehicle. KInda could do THAT on a snowmobile.

Is this original coolant gunking up my core? (from block heater cooking)
or
Can my thermostat stuck open problem be caused by block heater?
or both?

52merc

No. It is unlikely a block heater, especially the Ford OE 400W version, would get the coolant hot enough to even start opening the thermostat.

You probably have a thermostat issue.

If you are going to replace the thermostat, I recommend using a Ford/Motorcraft part, flushing the system, replacing the coolant with the new Ford yellow coolant, and using a vacuum filler system. Lots of threads on this forum about thermostats and coolants.