Cat 314C, not making adequate heat.

[Bandraboy]

Hi there, Im looking for some direction on how to trouble shoot this correctly.
The cab blower motor works but does not put out any heat. Engine coolant temperature and engine oil temperature gages show cold, even after running at high idle for a half hour. Seasonal ambient temperatures now are +-10 degC.
Max temp measured out of the vents in cab is 30 degC. Cycling the vents and temp controls work
Upper radiator hose is luke warm to the touch.
I replaced the thermostat, and coolant, but the issue remains.
S/N PCA01798

 

[92U 3406]

Does it get hot when you put it to work?

 

[Bandraboy]

We will put it to work tomorrow and i will advise you on the situation. Ty.

 

[heymccall]

A) using external temperature tool (point and shoot laser thermometer), measure temperature at t-stat housing.
2) measure temp at both heater hoses
c) verify temp blend door actuator movement when switching between heat and cool (circled in red, below) (accessed after removing plate on front of seat pedestal)
IV) verify no face plugging of heater core (dirt from poor filter maintenance, or running without filters)

 

[Bandraboy]

Ty, the machine is scheduled to work tomorrow, and will be gone for a few days.
I use a thermal imaging camera on my Cat phone to take measurement and get an instant visual on suspect systems. After 30 minutes at high idle, I measured 60 degC at the upper rad hose ( I could place my hand on it for a while, luke warm), and a max of 30 degC at the cab vents. Ambient temp today is +3degC. ECT and EOT displayed cold on the gages.
I have good airflow thru the heater/ evap core, with vent temps dropping to ambient in cold position.
The engine itself is not getting hot enough, no thanks to the direct fan drive ( no clutch or viscous hub). So I guess we do need to work these machines hard. I will update as soon as I hear from the operator.

 

[heymccall]

I has a PCA and I've never had a heat issue, solid drive fan and all.

Correction....Air always goes through evaporator core. The blend door sends that air through or around heater core.

 

[Bandraboy]

I has a PCA and I've never had a heat issue, solid drive fan and all.

Correction....Air always goes through evaporator core. The blend door sends that air through or around heater core.

Thank you, I will follow up on this when the machine returns in a few days.

 

[Toddgarage]

Maybe…. On the machines we have with air conditioning, there is a valve to shut off coolant flow to the cabin heater core. Even if you’re not running air conditioning, it’s nice not to bring hot coolant into the cabin during hot summer days.
However, it sounds like engine temperatures are still a little low.
Stay warm, stay safe.