Is my heater core bad?

[graphikg]

My heat is all the way up, my temp gage seems stable, but no heat comes out the vents. Do I need to replace my heater core? My cooling system is full of water, but I'm going to do 50/50 coolant/water. Could this be a problem?

Oh, btw, S50 motor, 88 cooling system (radiator, reservoir).

[fretburnr]

might be the water valve.... typically if the heater core goes "bad" it starts leaking coolant/water into the car; it's just a radiator.

[TexasTerp]

might be the water valve.... typically if the heater core goes "bad" it starts leaking coolant/water into the car; it's just a radiator.

+1 I've seen two heater cores go bad in friends' cars lately, if it did your interior would be soaked. check the valve and pipes on the driver side to make sure everything is flowing correctly.

[Julien]

I'm gonna say something is unplugged/broken behind your HVAC pannel, take the panel off and take a peak that everything looks ok. This is assuming that your car is well bled.

Julien

[reelizmpro]

heater valve probably.

[asubimmer]

you have the hoses going into the firewall the right way?

[graphikg]

+1 I've seen two heater cores go bad in friends' cars lately, if it did your interior would be soaked. check the valve and pipes on the driver side to make sure everything is flowing correctly.

How do I do this? My interior doesnt seem to be wet.

How do I check if its the heater valve?

edit: it was working just a week ago and since I replaced the radiator (expansion tank) cap the heater hasnt worked since.

[fretburnr]

Replacing a radiator cap is a strange way to get this, but i wonder if you might just have a super handy air bubble in the system.

park the car flat or a little uphill, run it until at full operating temp with the heater on full hot setting, and open the bleed screw on top of the t-stat housing. it may bubble out coolant, and then start trickling smoothly with no bubbles. That will let the air out.

Also, when I've had heater valves get sticky, you can try flicking the heater temp control from cool to full hot very quickly/firmly, smacking it clockwise... this sometimes opens a slightly jammed valve. But it's a quickie fix and should still be looked at more seriously.

[808BMW]

When my heater core broke, I noticed the leak by the burning hot mixture of water/antifreeze shooting all over my bare leg.
Can't miss it ;)

[graphikg]

HAHA ^^^

park the car flat or a little uphill, run it until at full operating temp with the heater on full hot setting, and open the bleed screw on top of the t-stat housing. it may bubble out coolant, and then start trickling smoothly with no bubbles. That will let the air out.

Also, when I've had heater valves get sticky, you can try flicking the heater temp control from cool to full hot very quickly/firmly, smacking it clockwise... this sometimes opens a slightly jammed valve. But it's a quickie fix and should still be looked at more seriously.

Actually, I dont have a bleed screw because of the swap. No bleeder on the t-stat housing (s50 motor) and no bleeder on the radiator (88 3 series radiator). Thanks for the suggestions though. I will try your second suggestion though.

But more research finds that my air comes out slighly warm. Not hot or cold, just slight warm. How do I get to that damn heater core radiator with a swap?

[Wh33lhop]

Did you install the lines correctly? Spider hose to the top outlet, back of the block to the bottom.

[graphikg]

Since the swap, the heater did work. All of a sudden the air gets warm at best.