It's a 92' with a 3.0. Engine warms up to operating temps fine, but the heat never kicks in. Hoped it was just a thermostat, so changed it out. Didn't think to look, but I just went to the parts store and got an aftermarket one, so it didn't have the jiggle valve like the OEM's do. Though I doubt that's why I get no heat.
The blower works fine, blows high, but never gets hot or even warm.
Just today I started it up, and sounded almost like the water pump was making a rattle. Maybe that is the problem, but I figured I would ask.
I searched but didn't see anything definitive. Really hoping it's not the heater core, but with the high temps in our area in the 20's I'd like to get this taken care of pretty quick.

Thanks,

Mike

 

A few things to check. Is the heater valve that controls the coolant flow to the heater core working? If this is a an automatic climate system, if so there may be an air mixing door that could be stuck.

 

To see if the water pump is working correctly, when the car is a normal running temp, squeeze the top radiator hose and slowly release it and see if you feel pressure surge as you release it. If you dont, then your water pump is bad. To test the thermostat, get a pyrex measuring cup and fill it with water. Tie the thermostat with string to the middle of a pencil (or something long enough to brace the top of the measuring cup like a chopstick) and suspend the thermostat in the water and stick ina cookingthermometer and slowly heat it up on the stove. Pay attention to the temperature when the thermostat starts to open, and when it is fully open, then turn the stove off and mark when the thermostat closes. Compare the temps to what the temps should be and you will be able to guage whether it is faulty or not. Are you smelling a strong sweet-coolant smell through the AC unit when you try to run the heat? If so, your heater core may be bad.

I hope this helps!

 

Is the heater valve that controls the coolant flow to the heater core working? If this is a an automatic climate system, if so there may be an air mixing door that could be stuck.
I took the dash apart, and I can see the cable move that you would control the hot/cold dial with from inside the car. When I switch from hot to cold there is a slight change in temperature between the two, so I don't think it is any of that.

I also warmed it up, squeezed the top hose and didn't really feel a surge of pressure at all. Which made me think water pump, but then after shutting off the engine, I went back to check the radiator caps, and smelled a very sweet smell when I put my head near the radiator. I forget now, but I think the a/c unit is front right on this car, either way now it's making me think it's the heater core. If so, it may be time for an upgrade.
Thanks for all the info though.

 

smelling some coolant when you stick your head near a radiator is one thing (and possibly normal), try to crank on the heat and you get blasted in the face with the smell coming from the air vents is another (and would mean the heater core).I would completely rule out the water pump and thermostat before you try and dinkle with the heater core. It is a beast of a project.

 

Yea I'm going to test the old OEM thermostat today, then if it looks good swap with the newer non-oem and check that one as well. After that I'd move to the water pump, since there really feels like theres no pressure building up.
I know putting your head next to the radiator would cause you to smell coolant of course, but the strength of the smell was more than normal. Smelled a lot sweeter than smelling straight out of the jug, which made me think that the hotter the fluid is, the more of that smell is has.

 

The heater control valve for the coolant would be inside the engine compartment, follow the heater coolant hoses.

If the engine is warming up OK, the T-stat should be OK.

Make sure coolant is able to circulate through the heater core. Disconnect the 2 hoses running to the core and flush it out with a garden hose.

 

So after tinkering around on it for a bit..........
the control valve moves fine with the hot/cold control, you can hear it moving somewhat inside
took the lines off the heater core inlet outlet, and attempted to try to clear it out some. I couldn't get anything to get in through the top hole, the hose water kept blowing back in my face, so started to go in to the bottom hole, where some sludge and chunks came out of the top, but not nearly as equal as the pressure coming from the hose.
So needless to say I'm pretty sure that it's completely compacted in there. This mixed with all sorts of other quirks with the car is finally making the decision a lot easier to get a new car.

Thanks for all the advise though!

 

Might try vineger and very hot water.

 

I would say i would try that, but i'm not sure if I have something that could force the water and vinegar through the system. Though maybe I can hook the hose up to the hot water tank, and get one of those garden watering attchments to put the vinegar in.
Or do you mean to put the vinegar in and let it sit there a bit to break up the sludge.