Plugged Heater Core on a 2.5 Year Old Truck?

[JWC86]

Recently had the heater core replaced under warranty on my 2020 Ford F350 7.3L due to it being plugged.

Going into this recent cold snap I had barely any warm air blowing from the vents, I assumed blend door actuator but after they all checked out the only thing that made sense was a plugged heater core, I checked the inlet vs outlet temp of the heater core, had 17 deg C diff. Its under warranty so I sent it to the dealer. The tech came to the same conclusion and replaced the heater core.

Unfortunately I have no idea it it was plugged with casting sand or what.

Truck was put into service in June of 2021 and has 108,000km (67,500 miles) / 3800 hours.

I did a coolant flush with the Ford product in May at 86,000km (53,750 miles) and filled with the Ford OEM coolant.

I was surprised to see a plugged core given the age? After some research I found quite a few examples of low mileage Fords with plugged cores.

Not sure where to go from here, I don't think that drained the entire system, probably just enough to get the core out. Perhaps another flush this spring/summer.

Maybe I should add back flushing the heater core to my list of preventive maintenance?

 

[65f100]

Some newer vehicles require a special machine to purge all the air out of the cooling system. Air trapped in the heater core would do what you described.

 

[eljefino]

Maybe throw a coolant filter in the heater loop to see what, if anything, it picks up.

 

[JWC86]

Some newer vehicles require a special machine to purge all the air out of the cooling system. Air trapped in the heater core would do what you described.

Like a vacuum filler?
I used a vacuum filler when I did the flush 20,000km ago.

 

[JWC86]

Maybe throw a coolant filter in the heater loop to see what, if anything, it picks up.

That was my first thought actually but I don't want to make any modifications while it's in warranty.

 

[FowVay]

Can you unhook it at the firewall? If so, see if you can blow some compressed air through the inlet and outlet.

And if it's under warranty then just hand it back to the mfgr and let them figure it out.

 

[JWC86]

Can you unhook it at the firewall? If so, see if you can blow some compressed air through the inlet and outlet.

And if it's under warranty then just hand it back to the mfgr and let them figure it out.

Have another read of the OP

 

[RooflessVW]

VW 2.0TDI cars do it too. EGR cooler does something to the coolant.

 

[FowVay]

Have another read of the OP

Gotcha! At least you got it fixed.

 

[MattPersman]

they were having issues with the transit heater cores with the non yellow coolant. Fix was replace core and flush then fill with the yellow coolant which is like corgard

Could be a coolant issue itself in your truck

 

[JWC86]

they were having issues with the transit heater cores with the non yellow coolant. Fix was replace core and flush then fill with the yellow coolant which is like corgard

Could be a coolant issue itself in your truck

Thanks. These trucks do have the yellow coolant thou.