Heater not warming up!

[95-F-2FITTY]

My truck is not heating up like it should it only blows warm air.The temperature gauge only goes up around the n or o on normal. And i also noticed my coolant resovoir never pressurizes. i can take the cap off without any pressure when its been running.

 

[Dzchey21]

Thermostats, winter front depending on how cold it is where you are

 

[TERRCO]

If it's low on water your heater may not work.

 

[zilla68]

mine does the same thing, when I put it on high idle it warmed right up, the engine is just not building enough heat, block off the grill and that will help.

 

[95-F-2FITTY]

Ok i will try blocking off the grill i am not low on coolant though. Im located in northern arkansas just got like 10" inches of snow!

 

[Ad8 PRODIGY]

I only blocked about half if mine off. Worked much better

 

[97BambiBasherPSD]

i always block it off completely. and like DZ said check the thermostat. only after the radiator is blocked though.

 

[95-F-2FITTY]

Alright so i blocked off my radiator last night then plugged the truck in its around 15 degrees outside this mornin. So i start it and let it run on high idle for 10 min and then i take off for work. It takes me about 15 min to get to work add or subtract a few minutes for red lights and traffic. When i got to work my temp gauge was on the n and just blowing kind of warm air.

 

[4x4given]

Sticking blend door or actuator? Mine was doing the same thing a couple weeks ago. Opened the glove box and dropped it down, looked under the actuator with a flashlight at the actuator shaft and operated the temp control knob and observed limited movement.

Popped the actuator out and tapped it a few times and it started swinging full range. (at least further than it was). Bought a new one at O'Reilly's (lifetime warranty) for about $30. Problem solved.

 

[Ad8 PRODIGY]

That's how mine was this morning. 25ish and a half blocked off grill. I'm gonna add more cardboard behind it to see if I can get it higher

 

[95-F-2FITTY]

I will give the actuators a check but what does your temp gauges run at?

 

[95-F-2FITTY]

Ok i checked the temp door and it is working full motion. Is the blend door the one that is located under the hood on the firewall?

 

[m j]

why no pressure in the cooling system? you have a leak

 

[95-F-2FITTY]

i pressure tested the cap and it tested all the way to 16 psi it is not leaking coolant anywhere either.

 

[Rideracelivemx7]

how cold is it? I know this time of year my theromostat doesn't even open, all rad hoses are ice cold and no pressure in the bottle. pretty sure anything below 50 or 40° these motors start to struggle to keep warm.

 

[Bugman]

If your morning drive is only 15 minutes you are not going to get the truck up to temperature. That is the problem with diesels, they run cool and need to be worked to get heat flowing. For that short of a drive you could pull the fan and not even worry about it along with blocking most of the radiator with some cardboard.

 

[JCart]

What I have done is purchase some plastic board (like cardboard only plastic) same width as rad and a few inches taller. Side it down between the rad (in front of) and behind the AC condenser in this way if fits right up against the rad. Seems to help, I really need a hotter Tstat I guess. Also have the Lund grill inserts but they really only keep the salt and gravel from hitting/coating behind the grill.

jrc