No heat

[MassS4B5]

What would cause a S4 to no longer have heat? I have no ac compresser delete but I doubt that has anything to do with it.

[getslideways]

Plugged heater core is one possibility.

Have you introduced air into the cooling system by replacing other parts in the cooling loop recently? Ait bubbles in the system from an incomplete bleed process can cause little to no heat.

Is the temp gauge registering normal operating temperatures?

[MassS4B5]

Temps were normal

[quattro16]

Clogged heater core. Whole dash has to come out.....

[Zba]

These threads usually don't start until the first frost hits lol.

Yes, you have a plugged heater core.
You can try to find a shop in your area that has the special Gates power clean flush gun and give that a whirl
Or you can just replace the heater core

[joeSfour]

I've tried CLR and a pond pump for several hours, and many different times. I can usually get my heat to come back for a couple days, but I definitely need to get mine changed.

[Jism]

What would cause a S4 to no longer have heat? I have no ac compresser delete but I doubt that has anything to do with it.

Temp sensor in coolant line. Should OPEN on hot and CLOSE when cold.

When it opens, it distributes the hot water across your radiator and / or heater core. When damaged, its stuck closed, and your engine is not running as it should

[Zba]

Temp sensor in coolant line. Should OPEN on hot and CLOSE when cold.

When it opens, it distributes the hot water across your radiator and / or heater core. When damaged, its stuck closed, and your engine is not running as it should

LOL Wut?

[Jism]

I think i was looking for the word 'thermostat' lol.

[getslideways]

Temp sensor in coolant line. Should OPEN on hot and CLOSE when cold.

When it opens, it distributes the hot water across your radiator and / or heater core. When damaged, its stuck closed, and your engine is not running as it should

the heater core would still have heat and the engine would overheat if the thermostat was stuck closed. The heater core is part of the engine coolant loop, regardless of thermostat position:

[Zba]

I think i was looking for the word 'thermostat' lol.

Haha, I figured as much but couldn't let it slide :P

[MassS4B5]

I parked my Tial 770 car four years ago because of this never got around to fixing it. Now I sold my daily and want to get back into my S4.

Will try the thermo first and hope for the best as I know rhe heater core sucks to get at.

[Zba]

If your engine gets up to temp and stays there it's not a thermostat. Don't even waste your time fixing that. Put those man hours into ripping the dash out. It's reall not that bad.

[getslideways]

/\ what he said

[themadscientist]

I don't advise trying to flush the B5 cores. They have plastic endtanks and usually leak without anyone's help. Dash isn't bad, just don't try to cheat the job. Follow all the steps. The plastic HVAC box is fragile.

[S4James]

gravity flushing it after giving it some CLR overnight should be safe no?

[derek2079]

I am having the exact same problem and the car's heat has to work to pass inspection. What can I do to get it working in order to pass, anything?