Winter is here and my heating isn't HOT!!

[datacrime]

My heater was blowing cold air so I checked the coolent and sure enough it was low. I topped it of and the heater got a little hotter but only when I am driving. When I stop and a red light it starts getting cold again.

Any thoughts of what my problem could be? It is a 01 B5 2.8.

Any help would be greatly appreciated!!

Thanks

[s42k5b]

I am going through the same problem in my b5 s4...i had no heat at all even when driving, and my car was running cold when i would get on the highway. So i replaced the tstat hoping it would solve my heating issue and it did somewhat. Now my heat works when im driving but gets colder when i come to a stop.

[s42k5b]

I guess we will both be having to replace our heater cores soon

[datacrime]

I hope it's not the heatercore... Those are pricey!

Is there anything else it could be?

[s42k5b]

Well its not even the price, its where the heater core is located which is in the dashboard whoch is a big PITA to remove...very time consuming.

[s42k5b]

i have no idea what else it could be..I have a very good tuner/mechanic who just works on b5 s4's mostly and he said he has never run into anything like this. The next thing i might do before the heatcore is replace my water pump.

[s42k5b]

if you fix the problem please keep me posted as I will do the same for you

[GetBoosted84]

2001's have an issue with providing A/C or heat when the car is not moving. Poopie, Bassed, and myself all have 2001s and we all have that issue.

As far as no heat while you are moving, that's a different story. What does your temp gauge get up to after the car is warmed up? Does it hit half-way in the gauge?

[deux321]

damn!!!!!
haveing the same problem here too. cold all the time......
subscribed.

[s42k5b]

damn!!!!!
haveing the same problem here too. cold all the time......
subscribed.

how are your coolant temps?

[FLACO X3]

same problem. took it to a shop and it is is the flapper motor if i remember right. the thing that switches between hot and cold air. at least my heated seats work.

[datacrime]

Ok after doing some research and asking around I think its one of these two problems.... Either its the thermostat which needs replacing or the heatercore and or waterpump.

I am due for a timing belt change soon in which I will change the water pump and probably change the thermostat too because I think there close together.

Any thoughts?

[kevin12]

01 as well and I also have no heat when coming to a stop, driving however is fine.
It must be something with the 01's like GetBoosted84 said because my 99.5 never had a problem.

[redsky]

I know a master tech at a VW/Audi dealership and he says those did have a problem with heater cores clogging up.

[CaSp3r9]

Replace the thermostat first because it's cheap (no more than $20) and relatively easy. If that doesn't work then you'll have to replace your heater core. Heater cores aren't incredibly expensive either, you just get screwed over on the labor to replace. I replaced the core in my friends A4 and it's not incredibly difficult just very time consuming but well worth the money you save.

As for having warm air while driving and cold when stopped, IIRC that is related to the flap motor failing. If you have access to a VAG-COM, it'll tell you if that is the problem. If nothing shows up, chances are it's your heater core.

[geeky]

has anyone tried doing a full coolant system flush with new 50/50 G12 mix?

thats what i did and replaced my tstat/CTS in my 97 and havent had any problems since.

[datacrime]

has anyone tried doing a full coolant system flush with new 50/50 G12 mix?

thats what i did and replaced my tstat/CTS in my 97 and havent had any problems since.

Before doing this you had the same problem, no heat at idle but heat when in drive?

[geeky]

Before doing this you had the same problem, no heat at idle but heat when in drive?

my heat was ERRATIC. It be jumping around between no heat to middle of the gauge. It would fluctuate in heat when just at a red light and idling. Increase to about 1/4 on the gauge between 1-3 gear and then once in 4/5 (or highway driving) the temp gauge would drop all the way to the bottom again.

but i did my tbelt with a friend on Wednesday and did a waterpump, tstat, CTS, and coolant flush and its been fine since. Car warms up to half way within 5mins of starting the car and then doesnt fluctuate at all. This is a A4 1.8TQM btw.

[Siena]

My 12V B5 quattro sport has the same issue - very cold air coming through.

My car has no aircon.

My gauge shows a regular 89 degree (halfway) driving or stationary, so definitely not the stat. A weak stat will allow the car to warm up, and blow warm air, however once doing a constant speed, will over cool, and the temp will gradually drop to cool / cold.

Looking forward to pulling my dash to replace the heater core.

[Gibbs]

i have replaced mt tstat, checked the flaps and done the aircon checks with vagcom and on my lcd display, still no hot air at any stage so looks like its gonna be a heater core this weekend :(

in the mean time i picked up a 12V in car heater/fan thing, does the job ok but not great.

Siena: how much is a core?

[Siena]

@ Gibbs: I take it your car has climate?

£118 delivered to your door.

[CthulhuAudi]

you might want to try a reverse flush of your coolant sys. before ripping out your heater core.