So, as everyone knows it's that special time of year when temperatures get a little nippy for some of us. I'll get straight to the point.

I have no heat whatsoever in my car, it's very, very lovely. But beyond having no heat, it's regularly below 35 degrees Fahrenheit where I reside in which case my VERY SMART audi decides for me that I can no longer turn air conditioning on. I'm assuming audi was thinking something like, "hey, who the hell uses a/c when it's freezing cold outside?" PEOPLE WHO NEED IT TO DEFROST THEIR ****** WINDOWS WHEN YOUR **** HEATER CORE GOES BAD.

Basically, the only way to defrost my windows is with air conditioning on. So I'm just fucked when my temp gauge reads the magic number of 35*.

Please tell me there's a way to get the air conditioning on with the defroster when it's below 35*F? If not I can't drive anywhere unless I pull an ace ventura and stick my face out the window.

Sincerely,
Happy B5'er

 

dont blame audi. every car's a/c wont work when its cold out. because its already so cold out the refridgerant will actually get so cold it will turn into a liquid and damage the the a/c system. as far as your no heat problem, its probably not your heater core. most likely a bad tstat.

 

Sorry some pent up frustration came out when I posted that as I had just got home from a near blind driving event. Thermostat is brand new unfortunately, car heats up normally and stays right in the middle of the gauge at all times. Recent maintenance - timing belt, and whatever tensioners etc came with the blauparts kit, water pump, thermostat, coolant flush. The mechanic that did the timing belt service mentioned that I had no heat and said he flushed the heater core while flushing my old coolant.

I don't know if I should believe if he really tried flushing it or not considering he gave me a $1,000 quote for replacing the heater core when I picked the car up.

I'm going to try flushing the heater core possibly this weekend because I finally ordered some of the meyle g12+ coolant so I have a couple extra bottles. Not sure how much coolant I will lose, don't know the
process very well but I need heat asap.

Thank you for the reply.

 

i can see 1000 for a heater core. its labor intensive in any car, but still high. but if your going to flush the heater core, just use water at first and flush the whole coolant system. no need to waste good coolant. once drained replace with half and half coolant and water. before you do any of that though have you checked the coolant temp sensor? it is a known problem on b5's. i dont know which engine you have but either way its the one near the fire wall. if its blue it is most likely bad. the green temp sensors are the revised ones

 

I have a 98.5 2.8 with 145k just for reference.

Can a bad coolant temp sensor cause a no heat issue? I have zero heat, at any RPM, etc. Never felt a lick of heat come out of my vents haha

Any way to tell if the sensor is actually bad? I'll look at it today after I get off work, I don't have any CEL, never have which is odd for a B5 I know.. and I know the bulb works lol

 

a bad coolant temp sensor won't cause no heat. does the blower motor work? does the temp gauge get up to temperature ok? i would just buy a sensor since it's only 20 bux. you'll go through a lot more hassle trying to determine if it's good or bad

as for defogging, there's a button for that on the climate control. there's one for the front and one for the rear. it won't blow AC but it'll use the cold air from the outside.

 

Defiantly try flushing the heater core first. What I would do is feel both lines running to and from the heater core. Feel them and see if they are both hot/warm.. If one is hot and one is cold then you know your heater core is plugged. Another issue that could cause this is a problem with your blend door or an interior temperature sensor.. if you have access to a vag com you could check for codes or use this procedure:

AudiWorld Tech Articles

What does your coolant temperature gauge show when you are moving? This should rule out the Tstat, as far as I can remember you should def be getting heat once it barely moves away from C.

 

Both lines of the heater core are warm, I believe the blend door works because I've listened for it when changing the temperature from Lo to Hi on the climate control... I wish I had access to vag com... Temp gauge always heats up normally and stays right in the middle, it's a brand new tstat.. Trying to consider all possible options before replacing the heater core. Thanks for the replies

Oh and as for the button to defrost... My windshield doesn't defrost unless the defroster is on plus the snowflake showing air conditioning is on as well. Or defog maybe I should say. It does not defog at all without the air conditioning. It would defog if I had heat though.

 

Did you look to see if you have any codes using the other method that I posted? Did you find any codes?