Engine/Transmission (1994 - 1998) Thermostat replacement

[SAndreasen]

Well as part of my no heat issues i replaced the thermostat the old one fell out before I could see which way it went so does it go with the spring toward the block or toward the thermostat housing ? My trusty pos Haynes manual shows a picture of it going both ways ! I covered the radiator with card board and got the engine temp above 190 then I checked both hoses to the heater core both around 180 degrees but still hardly any heat

 

[Bob4x4]

Spring towards block.Both heater hoses should be hot,one side slightly warmer.If one side is much cooler you have a plugged heater core

 

[GAmes]

Before the air gets to the heater core it has to pass through the AC evaporator. It can be cleaned by removing the fan (it is turning, correct). The cavity between the fan and the evap needs to be vacuumed out more than likely. Then spray a non-corrosive cleaning agent on the evaporator. I use simple green. Once it has soaked used a low volume, low pressure water stream to rinse the dirt and soap from the evap. If done correctly the liquid will exit via the HVAC drain tube. If excessive it will leak onto the floor. The other option is to remove the dash and HVAC, disassemble and clean.

 

[SAndreasen]

Yes the fan is turning but not Very fast I'm going to pull it out and replace it and vacuum and clean the evaporator

 

[SAndreasen]

Replaced the fan and vacuum the the evaporator and re replaced the thermostat heat is warm not hot still I guess it's coming summer anyway but I'd still like to have heat at night in even in the summer it gets cold here , actual temp readings are as follows Left heater hose 209 degrees 211 right heater hose thermostat 200

 

[DonFitzwater]

Replace your heater core. I've done several in the last couple years, all with your symptoms. The heater cores will plug up in the tubes and some water can go through but no useable heat transfer will happen.

If you want a quick fix, run pure Polyzag through you heater core only. Let it soak for approx 15 minutes and immediately flush with a garden hose in both directions. This works about half the time but be ready for a LEAK! The stuff is very corrosive and if the inside of your heater core is eaten up badly, you'll spring a leak.

 

[SAndreasen]

Do you have to pull the dash to do the heater core on these

 

[BigPapa]

Oh, yeah.......

 

[SAndreasen]

Well I may just put up with it until winter what else should I check ?

 

[BigPapa]

Blend doors.

Your temps, in my opinion, look good. Sounds like you have a door that's not operating properly or something's blocking air flow.

 

[GAmes]

Do you have to pull the dash to do the heater core on these

Issue 46, page 12

 

[SAndreasen]

Blend doors.

Your temps, in my opinion, look good. Sounds like you have a door that's not operating properly or something's blocking air flow.

May have to pull the dash to figure it out I guess

 

[GAmes]

The blend door lever is above the heater core.

 

[HHhuntitall]

Pull the heater core hoses, take a garden hose and put on one side, and see how much water is coming out the other line. If not much, it's stopped up and probably corroded beyond help. If it is flowing good water, then your blend doors are broken/disconnected, and you need to look under the dash.

 

[SAndreasen]

I can't see the cable just but removing the glove box it must behind where I can't see

 

[HHhuntitall]

If I recall correctly, the stupid 98 and up trucks had an electric blend door, operated by an electric motor.... Which has a tendency to break off the arm on the door.... somebody correct me if I'm wrong. The older trucks had a cable operated door and rarely fail. But an engineer has to earn his money somewhere, making "BETTER" ideas come to life....

 

[GAmes]

I can't see the cable just but removing the glove box it must behind where I can't see

It is necessary to tip the dash back to see the cable.

 

[SAndreasen]

Thanks for all the help guys it's getting warmer so I'm just going to run it till winter

 

[DavidC]

If I recall correctly, the stupid 98 and up trucks had an electric blend door, operated by an electric motor.... Which has a tendency to break off the arm on the door.... somebody correct me if I'm wrong. The older trucks had a cable operated door and rarely fail. But an engineer has to earn his money somewhere, making "BETTER" ideas come to life....

I don't think it broke anything on the door but breaks the plastic coupling linking the motor to the door and the motor is in a real PIA place. There is a metal coupler available just need patience and a little Houdini moves.

Dave

Dave

 

[SAndreasen]

I sure have had bad luck with buying trucks without heat lately all my friends say the heat never works in dodges but I know I've had dodges that the heat has worked before ... I think ?