Lukewarm Heater

[XxJamesAxX]

Ok guys never noticed this as being a problem on the cool days but now that we're getting some cold mornings my heater is not getting hot, warm at best. What should I check for? I attached a picture of the temp. Gauge after a 15min idle and and 15min. Drive to work this morning.

 

[Johnn123]

First thing to check is to see if the thermostat is stuck open. If it is replace with a good Stant 195* stat. Also check for a dragging/sticking fan clutch.

 

[SaggySenator]

I've got the same issue over on the "Engine Never Warms Up" thread. My Thermostat seems to be working. Must be the viscous clutch on the fan. I'll let you know if I fix it...

 

[XxJamesAxX]

Does ur truck reach same temp as mine?

I've read before these motors run cool, but figured mine was getting warm enough to blow hot air. Atleast goin by be temp gauge. Easy enough to replace the thermostat though so I will try that.

 

[SaggySenator]

Yup. My dash looks the exact same while I freeze my butt off...

It appears that the fan clutch has stuck, so its constantly blowing cooling air. Check your radiator hoses. My upper (supply) is hot while the lower (return) stays cold, which tells me that the thermostat hasn't even opened yet. I recently replaced it and flushed the system and heater coil thinking that was the issue.

As of right now, I cannot get the fan clutch nut loose... PB blaster and a pipe aren't working. And yes, it is left hand threads.

 

[XxJamesAxX]

Thanks for the info will check mine,

 

[SaggySenator]

Fan clutch replaced. It had standard (right hand) threads and after being broken in over the weekend seems to not be staying engaged at cooler temperatures. At first you could really hear it. Noticed the pep immeadiatly though as the drag must have been drastically reduced. Need to fill up and drive about 400 mi before I can give a MPG report.

The heater is blowing a warmer shade of lukewarm, but the block still isnt heating up enough to open the thermostat. The mornings are in the low 40s and the days in the 70s, plenty warm for this thing to reach 195. The return line is still cold (bottom of the radiator) so I know the thermostat isn't open. Any ideas?