I have a '97 Dakota with a 3.9. It doesn't have a lot of heat. Coolant level is fine, engine heats up fine, both heater hoses get warm.

 

Welcome to the forums.

Are you sure the engine is reaching normal temp? The thermostat could be failing.

A common problem is a partially clogged heater core. You can try to flush it. Disconnect the hoses and run water through it, then add some radiator flush and let it sit for a bit, then flush it some more.

Or, if it's been a while, flush the entire system.

 

I am having the same sort of issue with mine. I have a 99 with the 3.9 and I barley get the temp guage into the normail operating range. It has been gettinbg colder here and I dont have a long commute so I have even tried pluging in the block heater but no success. Any one know what the stock thermistat is set to crack at.

 

That is a common problem. Seems as if the heater core gets blocked or clogged up with slimy gunk. When this happens you will get very little hot air, or NONE. I usually back-flush the heater core about once a year on my 99 (V8) Dakota, which tends to keep the hot air moving fine.

A water hose will do the job, but I have found it works better to put some water in the lines and use a air compressor to blast the gunk out. Usually takes 5 minutes to get everything ready and about another 5-10 minutes to flush it.

I should take the time to do a total flush, but I have been living life in the fast lane.

 

Yup.. had same problem with mine.. did a back flush on the core spit out brown crap and then ran the hose till the water was clear.. then flushed opposite way.. put back together; burp the system and boom had heat..

Only other thing is to make sure you have the right T-Stat and that it's working. You'll get less hot heat off a 180 than a 195 of course.

 

Barely in the temp range I assume means just above the left line, not near the middle.

Seems the t-stat needs replaced. Some other replies probably have good engine heat but it is not transferring through their heater core, thus back-flushing helps them.

Not sure if you want the 180 or 195 t-stat... depends what was working well for you before.

My $.02, good luck!

 

My scan tool had the temp at around 200 degrees after it was fully warmed up. I bought some coolant flush stuff and will be blowing out the heater core with my hose.

 

Mt,

I think you'll find it's a blocked heater core. It's not moving enough water from your description.

 

Got everything flushed. Pretty confident it was just a plugged heater core. It was almost 50 degrees so it's kind of hard to tell but it definitely felt warmer. I really didn't notice too much nasty come out of either side of the heater core hoses, though.

 

the other issue is the door not switching to heat side.. you might check and make sure the hose right under the driver side is plugged in there.. its a vacuum hose. make sure it's on there good and an also check to make sure it's getting good vacuum and ou don't have a leak somewhere.