Heating Issue

[jimbob_1000]

I have an ‘87 325is, and there is no heat coming out of the vents.

I have a friend that is pretty good with cars (well a lot better than me) and we looked at it today. We sourced that the water running through the reservoir to the radiator and out to the thermostat is hot but after it leaves the thermostat it is cold. The thermostat gets hot like it should but everything from that point on is cold. We checked all the temperature levers and they are pushing and pulling, opening and closing. We checked the heater core and the pipes leading into it and they were cold. So I don’t think it is the heater core due to nothing hot even getting to it.

Oh and we check the valve in between the thermostat and the heater core, we unhooked it and ran it under cold and hot water to see if it was opening/closing and it checked out. Is there something between the thermostat and the heater core that I am missing?

I thank you for your help in advance.

JIM

[325ise30]

The coolant to your heater core will flow regardless to the thermostats position, as the connections are before it (as in most cars for steady heat supply). What you are experiencing is a defective heater core valve (located on heater core) or clogged heater core also common.

[jimbob_1000]

The coolant to your heater core will flow regardless to the thermostats position, as the connections are before it (as in most cars for steady heat supply). What you are experiencing is a defective heater core valve (located on heater core) or clogged heater core also common.

Thank you for your help.

but my question to that is, this can be a clogged heater core when nothing hot is even running to it? I'm just not that good with cars so I'm learning. Thank you.

Jim

[325ise30]

If the coolant isn’t flowing at all the hose will remain fairly cold but you can expect some thermal heat transference maybe half way up the hose even with no flow. The only way to test for sure is to take something apart, pull the hose that goes from the core to the therm housing at any end, blow threw it with compressed air or other. Chances are if is clogged it may clear but if it’s the valve that’s not working it probably won’t. Remember the heater core valve on your car is electric so check it for power to.

Note: you will lose coolant doing these tests so try to keep pets or other, free of the area.

[jht3]

the connector on my temp knob wasn't plugged in, so i had no heat at all. i was getting all worked up about a blocked heater core until i pulled the dash apart and found the dangling wire. check the simple things first

[cochran]

disconnected wire

I know this is an old thread, but I have the no-heat thing going.

What colors are the wires running to the knob? I only see one electrical connector, a two-wire, running to the knob.