Lack of heat (should be unrelated to blower motor)

[Bobbywolf]

Ok, my car does not heat up. If it runs for about 1/2hour, you can feel some lukewarm air from the vents. Also, the temp guage just barely lifts from the far left. I figured it was the thermostat so I replaced it, and even checked the new one in a pot of water on the stove with a themometer to be sure it worked. Still no heat. I dread to even ask the question, but could it possibly be the heater core? Any other commen causes?

[Black2000Ranger]

Well if your temp gauge doesnt go up, then it's probably the thermostat. If all else fails, put a peice of cardboard in front of 3/4 of your radiator.. That'll let the coolant get warm.

[mightymoose_22]

When's the last time you flushed the system? It is possible the heater core is plugged up... and the temp sensor is after the heater core... water may be flowing through the engine normally.
Does the radiator cap heat up?

If it's been awhile since it was cleaned out, run a Prestone cleaner or flush through it or have it professionally cleaned out... might help.

[dougand3]

Search the escort forum for "overcooling". Lots of threads.

[Davescort97]

The thermostat is in the line going into the heater core. If the heater core is plugged up you aren't going to get a flow of coolant through the stat. There are 2 rubber hoses running into the heater core. Take the hoses loose from the heater core at the firewall. Take a garden hose and flush the heater core both ways. I think this will solve the lukewarm heater and the low heat register on the temp. gauge.

[Bobbywolf]

Well, what I did was disconnect the inlet and outlet from the heater core, and used a union to join them togeather. I thought my problem was fixed because the temperature did rise to like 1/3 when idleing, but when I took it for a drive, it dropped down to just below the top of the red again. It is like my rad is cooling too much.

I'm not really sure where to turn now. Maby the heat I was getting just wasn't very good because my blower was running slow (fixed now). Maby my whole problem is just a faulty temp sending unit, or guage. The temp sending unit is cheap, so I'll go ahead and replace it. Thanks for the info guys!

[Bobbywolf]

No dice,

Was thinking about the problem, what if my radiator fan is on all the time? Shouldn't there be a temperature sensor that turns it on and off? If this is 'stuck' on, could I be overcooling my radiator?

[lougheed]

This thread is so Deja Vu. I've been down alll those paths. My 91 GT runs so cold that I have driven 40 highway miles with the fan disconnected and it never heated up.

If I leave it idle, it will warm up to normal temperature, the fan will even turn on and cool it down. It will cycle like that all day long. But, as soon as I give it some RPMs (say 2000 or higher), I can see the temperature needle go down.

When the temperature is in the normal range, I feel heat coming out of the heater and actually watch the temperature drop when the blower is on high.

Now, I'm thinking of some exotic leak in my head gasket might be the culprit, but not making it fit all the symptoms.

[Bobbywolf]

Well, the fan isn't stuck on. In fact, it almost never comes on, except for when I sit a long time at idle. I'm basically running out of components to blame it on.

Checked or replaced:
1. Thermostat
2. Heater Core
3. Temperature sending unit (for guage)
4. Coolent temperature switch (for rad fan)
5. Radiator Fan

Basically, I'm down to the thermostat housing itself, and that's it. There isn't anything else in the circuit besides hoses! Like you say, it may be some exotic block issue, but I doubt it. Basically I'll need to replace the thermostat housing, and the thermostat (yet again) to rule that out, as it seems to be where the problem is coming from.

On the upside, the weather is warming up again, so I might just ignore the problem again until the fall!

[dougand3]

I tried 3 different housings...2 used and 1 new - No joy. Tried plugging the bypass holes that circuit through the 2 towers - No joy. Tried 4 different tstats - No joy. Flushed and backflushed the heater core with CLR - a very little bit of joy.

One other thing I thought about trying...From totally cold, the upper rad hose gets pressure more quickly then it should. That tells me the fluid is moving thru OR around the Tstat.

Maybe try RTV sealant around the tstat seated in the housing?

[twlunn]

Originally Posted by dougand3

I tried 3 different housings...2 used and 1 new - No joy. Tried plugging the bypass holes that circuit through the 2 towers - No joy. Tried 4 different tstats - No joy. Flushed and backflushed the heater core with CLR - a very little bit of joy.

One other thing I thought about trying...From totally cold, the upper rad hose gets pressure more quickly then it should. That tells me the fluid is moving thru OR around the Tstat.

Maybe try RTV sealant around the tstat seated in the housing?

Did all the above too..http://www.automotiveforums.com/vbul...d.php?t=486552
Snowmoblie suit fixed it..