We have a 91 Dodge Dakota 3.9L. We got it from my mother-in-law's boyfriend since it was sitting on their property for 6 years and our car blew an engine again.

We had to replace the radiator and hoses right off, and put a remote starter in because we could not find a solenoid for it. We just replaced the windshield and fixed the wipers.

Now, we have a major coolant leak but cannot find out where it is leaking from. We are thinking a freeze plug but how do you replace them? And does anybody know where all of them are? It mostly leaks when sitting, but probably leaks a little while driving too. We lose the top of the radiator every trip even if it's just a mile and back or 50 miles.

The valve cover gaskets are soon to be replaced, oil everywhere. A mechanic said the rear main seal was blown. Really we do not lose a lot of oil. We did an oil change when we did the radiator and have only put many a 1/2 a quart into it since (about 6 months and 8,000 miles later.)

It doesn't have a heater core in it or lines for it. Now no air is being blown through vents or defrost. Is it because of the heater core? Or is it the blower motor? We just need to get the defrost to work for inspection.

Overall, the truck is holding up good. Needs a paint job but that is not on the top of our list. But really need to get the coolant leaks and defrost fixed very soon for winter.

We are thinking if we get the leaks we know of fixed we can clear off the engine to find other ones. Right now it is just all oil and water mixed. Any help would be greatly appreciated.

 

The leak could be anywhere. If needed get a UV detector kit. Very easy to use.
If it is a freeze plug, the proper way is to remove the plug and press in a new one. It is best when the engine is out. A temp fix is an adjustable rubber plug. They can come loose or crack and you could overheat. The freeze plugs are best to change out when rebuilding a motor. Or even just swapping a used one changing them are easy. Cheep insurance, or else things like that happen.

Valve cover gaskets would be very easy. If your rear main seal is bad then the oil pan and more has to come off. All gaskets/seals should be changed out when rebuilding. Or even installing a used engine all gaskets/seals should be replaced. Cheep insurance, or else things like that happen.

A heater core is stock from factory. If it is missing someone took it out. If someone did that they could of took out the blower motor or cut wires ect. Just start checking what has power and what doesn't.

 

Check your blower motor resistor (in the FAQ). While the FAQ says "blower doesn't work on all the settings", it is possible for the resistor to fail in such a way that none of the settings work. I just replaced one like this - normally one of the outputs fail, but this one had a failed input (nothing in = nothing out). It's easy to check and something like $7 for a new one.

You may get lucky and your inspector only check for moving air from the defrost - or they may check for HEATED moving air - which means you need to get your heater core fixed/replaced. It seems strange for someone to physically remove a heater core, when its so easy to bypass it with a hose in the engine compartment (which you'd have to do anyway if you removed the core). Is it possible that the truck has the heater core, but not the A/C evaporator? A co-worker has a dakota that was originally sold in PA which came from the factory with no A/C.

Keith

 

I replaced the blower motor resistor and we now have air blowing, so at least that was an easy fix. Now for the heater core.... for some reason my mother-in-law's boyfriend decided to take it out and cut the hoses to it since it was leaking.. really he's a bit insane, some of the things he did to this truck.

Anybody have step by step instructions on replacing to heater core? And a hose diagram maybe? We have no clue where the hoses are suppose to go since he cut them off and just bypassed the heater core when we removed it.

 

Check the FAQ for the service manual. This will give you all the info you need.