I have a 95 v8 Dakota. My engine will not get up to normal temperature or blow hot air, even after driving it for an hour. If I turn the heat on at its lowest blowing speed it will eventually blow luke-warmish air, but definitely not hot and will blow cold if I turn it up any faster. The engine temperature gauge is sitting a couple hairs above the cold line, when in years past it would sit right in the middle of the hot and cold lines. I just tried replacing the thermostat and checked coolant levels (all normal). I didn't bother checking the heater core because I don't see how a plugged heater core could cause my engine to not get up to normal temperature. Any suggestions? Please help, it's freezing in Chicago right now

 

Check the post about no heat. My '93 V6 does the same as yours. I just had new water pump, thermostat and coolant flush, thing still barely gets warm. Engine, I mean. Gauge is just above cold mark doing 70! Forget heat! I read this:

I had this same problem for two years. Heat punp was OK, thermostate was OK, heater core OK....... the problem was fixed back flushing the heater core ......... very easy, you can do it your self using a garden hose . My Dokota has good heat now.

Won't help engine temp though. Let's see if we can find out what's causing our Dakota engines to run so cold.

 

If your heat is strong, I'm willing to bet the coolant temp sensor for the gauge is faulty and giving you false readings. Just an idea tho

 

Yeah. I'm going to try back-flushing the heater core with the bleach and hot water method this weekend and see what that does. I don't know what else can cause my engine to not warm up. I've replaced the thermostat twice with a 193, and then a 195 degree stat thinking maybe the first was faulty or not high enough of a temp. That didn't change anything...

 

I run a 180 in mine and the gauge only reads about a quarter into the normal area when warmed up. It's very possible you have a bad coolant temp sensor. There are two on these motors. One has two wires, which runs to the computer, and the other has one wire, which runs to the gauge cluster. Try changing the one wire sensor as well

 

The engines arent running cold. You can count on that. Either your sensor is bad or your gauge.

also a good way to chech if your thermostat is bad is to remove it and place it in boiling water for a minute. If it opens, its good. If not it needs to be replaced.

If your getting luke warm on low and cold on high it is most likely your heater corr. Backflushing will do it. I would suggest buying a kit as it comes with a t-style connecter so you have easy access for backflushing again or for flushing the entire coolant system.

 

I have heat again!! And it's hot like a furnace I backflushed the heater core with a garden hose and that was that. My temperature gauge is still running cold, but I am sure that my engine is up to normal temp. I bet if I replaced the temperature sensor it would read normal, but I'm not too concerned about that right now.

 

I have a 1992 dodge Dakota as well which I've owned since new.
A few years after I had it I had to replace the radiator, and later on the water pump. It's been a while since then and while I didn't notice any change in engine temperature or interior heat, it's been a problem recently. I can't recall what the OEM radiator was whether two core or three but mine has A/C so when I replaced it I went with the three core.
My problem has been same or similar as described here in forum posts. I've talked with a Stant rep (rad cap and thermostat manufacturer) and haven't come up with a solution until recently.
It seems some haven't considered the problem fully. Mine was engine temperature not running in the normal operating range ( more or less middle of range on gauge ) mine was running towards the lowest and even outside the operating range which wouldn't supply sufficient heat both fur optimism engine temperature let alone the heater core . I replace at least two thermostats with no change, put cardboard across rad, no change, even changed rad cap, no change. This was even in summer still could not get this engine to warm to normal operating temperature.
I've also noticed when removing rad cap there isn't any noticeable pressure and I can stick my finger in coolant without sacking finger.
I recently was discussing this with my long time friend and he mentioned a physics law " boyles law" which put simply when volume if a gas/liquid is increased pressure drops.
The light came on, since I may have increased the volume I've now changed the dymamic of the cooling stsyem. The pressure obviously must have dropped lowering the boiling point. I've yet to try a higher pressure cap from stock 16lb to maybe an 18lb. There is another ratio in which for everybody's if pressure the temperature of the coolant is increased by 3degrees Fahrenheit. In addition to that the ratio of mixture of coolant versus water also affects temperature of coolant . So I'm investigating where u can get an 18-20 lbs radiator cap for this vehicle and see if that at least makes the engine warm to where it's supposed to run.
Ron