Ok I have 2001 3.9l ram and I just replaced the heater core. I've been without a heater since 2008 so I've had the two hoses going to the heater core routed together since 2008. So when I installed the heater core I wasn't exactly sure where the inlet/outlet hoses went. Basically I put the hose coming from the engine to the passenger hookup on the heater core and the hose from the water pump to the driver's side hookup of the heater core . My heat isn't very hot even after driving on the highway for over
20 mins. Did I hookup the inlet/outlet hoses right? Does it matter?

Thanks

 

Probably an air bubble in the system. Try and get all the air out first.

 

Yeah, the heater cores are notorious for trapping air, and then not being real efficient......

 

just an idea .... but hows the thermostat.....if someone was to have replaced it at some point with a failsafe thermostat and it acted up it sticks open to prevent over heating...whats the temp read on your gauge (provided your gauge is working properly)

 

I'm having the same problem. I'm freezing to death after installing my new heater core. I'll try the "get rid of the air thing". Crappy problem to have in Minnesota.

 

You will get little to no heat if there's air in your heater core. The best way to get all of the air out is to park on a hill so that the front of your truck is a few inches higher than the rear.

 

Don't rule out the radiator cap if it's weak it won't hold pressure therefore not pressurizing your system.

I wasn't getting any heat out of mine thinking I needed to replace the core so I flushed my system and replaced the cap and wa la I have heat now.

As strange as it might sound it worked.

 

My engine temp gauge reads around 150(max), I replaced the thermostat around 40k ago, it's always ran below the 210 mark but now that I think about it it has been running cooler now, than it did right after the thermostat change. Do you think the thermostat is stuck open? The heat gets warm but not as hot as it should. If the thermostat is stuck open is there a way to unstick it or do I have to replace it? To the reply of replacing the radiator cap, is there a way to test if it is in fact the cap?

thanks always for ya'lls help

 

You can have the cap tested at most any shop. They really shouldn't charge for that, but, they might.... could always just pick up your own cooling system tester..... then you could test whenever ya felt like it.

Only fix for a stuck thermostat is replacement.