No heat in cab

[Axel]

I have a 2016 cummins 6.7. Just noticed that my truck is only blowing lukewarm air.
I have changed the thermostat no change. I checked the hoses going to heater same temperature going in and coming out. Blower is working fine, but only getting lukewarm air....any ideas?
Any help what to check next would be greatly appreciated...

 

[TMyers]

My 2013 is bad to hold an air pocket in the coolant system. If you have access to a coolant vacuum, I would try that before going deeper. Next step would be the blend door.

 

[gsbrockman]

Sounds like you have a restricted heater core. How many miles on truck? Why the thermostat change? How much coolant did you replace.....and what type?

 

[Cummins12V98]

When coming South from NW WA to SoCal there was some COLD freezing weather we were passing thru. My heater simply didn't feel like it was putting out more than warm air. Can't say what i did but it decided to actually put out HEAT. Then it went back to just putting out warm air.

I figured I would talk to the dealer about it as I keep getting a notice on my radio about my tailgate recall.

 

[Axel]

I have 150000km or just shy of 100000miles on it. It seamed to me that the thermostat was stuck half way open or something like that. So I decided to change it with the OE cummins thermostat. The coolant I use is from Dodge OE coolant.
The level is good, but there is no more radiator cap and I think the air is supposed to go out the cap of the reservoir? Wondering if the cab might be at fault....

 

[Axel]

I have checked the lines in and out of the heater core and they both feel hot....so not sure if it could still be blocked...

 

[Axel]

Was hoping to avoid the steelership since I have done all my own maintenance up to now....
But then again there are still some outstanding recalls on my truck...

 

[Axel]

My 2013 is bad to hold an air pocket in the coolant system. If you have access to a coolant vacuum, I would try that before going deeper. Next step would be the blend door.

How hard is it to get to the blend door?

 

[Ozymandias]

You sure dont want to tear apart the whole dashboard without a proper diagnostic before...
The dealer can check the blend doors with its wiTech, if they do their full travel, if they stick, if an engine as bad, what values the several sensors deliver to the HCU and so on.
Then you might tear your dashboard out after you know what you want to repair.

Gen3 were famous for broken blend doors, but we hear rarely to non of that at a Gen4.

 

[EDankievitch]

Heat in my 2013 has never been as good as the 12 I had. The 12 had a 205f thermostat the 13 has a 190f. And the cab is twice the size along with the 13 having the 2nd radiator of the super heavy duty cooling package. The winter cover helps but you don’t want it on if outside temps are above 40f.

 

[Axel]

You sure dont want to tear apart the whole dashboard without a proper diagnostic before...
The dealer can check the blend doors with its wiTech, if they do their full travel, if they stick, if an engine as bad, what values the several sensors deliver to the HCU and so on.
Then you might tear your dashboard out after you know what you want to repair.

Gen3 were famous for broken blend doors, but we hear rarely to non of that at a Gen4.

I will book an appointment with dealer.

 

[Axel]

Heat in my 2013 has never been as good as the 12 I had. The 12 had a 205f thermostat the 13 has a 190f. And the cab is twice the size along with the 13 having the 2nd radiator of the super heavy duty cooling package. The winter cover helps but you don’t want it on if outside temps are above 40f.

I have had this truck for 3 winters here in Canada. Never had a problem till now....Have the winter cover, but never used it. It is parked inside my shop. Guess will see the dealer and find out..

 

[Ozymandias]

Always used the winter cover on our journeys beyond the Arctic Circle in winter.
Closed it completely at 0°C. Its really a good addon.

 

[Ozymandias]

Wasn't there a coolant bleeder screw on the EGR Cooler on this newer Trucks?
I think @RVTRKN told me so.

 

[gsbrockman]

Wasn't there a coolant bleeder screw on the EGR Cooler on this newer Trucks?
I think @RVTRKN told me so.

Not on the 2013 & newer trucks....

 

[Ozymandias]

Thanks @gsbrockman for clarification.
Would have been a to easy fix.

 

[firefighter_2000]

You didn’t happen to do a delete since last year did you?

 

[Axel]

You didn’t happen to do a delete since last year did you?

Truck is Stock . No delete No tuner. Going into Dealer next Monday

 

[Cummins12V98]

Can't wait to hear what they say as mine is acting the same.

 

[Axel]

Can't wait to hear what they say as mine is acting the same.

I will post update as soon as I find out. Going in Monday at 1pm.