Trying this in a different forum since I didn't get any responses before...

Can someone tell me, or possibly upload a picture of where the thermostat is on a 2001 A4 Quattro 2.8L V6? I've read where it's next to the water pump and also by the alternator, even behind the cambelt, so I'd like to know before I try figuring out how to replace it. I emailed the audi dealership, and they said it's behind the water pump. Does this mean I would have to remove the waterpump to get to it?

I'm not getting any heat coming out of my vents, and my temperature gauge stays by the cold reading until maybe 20-30 minutes of driving, and it rarely goes up to the halfway point. Usually only goes up 1/4 of a reading. I usually keep my heat turned off since there's no hot air, but if I turn it on after about 10-15 minutes of driving, hot air will come out, but then quickly turn cool again.

From what people have told me, this is my thermostat, which makes since with the way the temperature gauge is acting.

Also, I had recently taken the vehicle in to have the alternator replaced. They had to take apart the front of the car.... of course.... so I'm wondering, would air in the heater core cause me to have these symptoms? Neither of the heater core hoses are hot to the touch after driving. I know the heater works with it blowing hot air when I switch it on after driving a little bit, it just goes back to cold air after a few seconds. I've read posts of people having similar problems. Has anyone been able to find a problem other than the thermostat? Granted I'm not very knowledgeable on cooling systems, but would a thermostat control how the heater works? I know it regulates the temperature of the coolant, but if it's stuck open, would it cause the heater to blow cool air? Even when the temperature gauge does get to the mid-range, there's still no heat blowing out, so that makes me wonder why it's not working when the coolant temperature is where it should be.

 

It is pretty much smack dab in the middle in this picture.




Here is a close up (different car) it is behind that gray/black cover just to the left of the gaping hole where the water pump goes.

 

Yup it's pretty much a full frontal teardown. If you're at all approaching your timing service interval, do it now and save the duplication of labor. I changed mine once without pulling the timing system off - if you slide the timing belt forward so it's half off the passenger cam, you have just enough room to pull the channeling plate downward and wiggle the thermostat out. You'll want a second person to hold that belt in place though, just as a safeguard.

 

Well crap.... Thanks for letting me know. Was hoping it wouldn't be that difficult to do.

 

So this morning, the outside temperature was warmer than it has been, and my car heated up like it should. I guess with the metal expanding with it being warmer outside, it must have unstuck the thermostat from being open. Anyways, even with my temperature gauge staying at the mid-point the whole time I was driving for 35-45 minutes, I still didn't have any heat. I would turn it on, hot air would blow, but then after about 10 seconds, it got cool again. I could do this periodically throughout my drive. This doesn't sound like my thermostat is causing me to not have any heat.

Does anybody have any ideas on what it could be besides the thermostat or has anyone had this same experience?

 

try flushing the heater core.

a much easier job than replacing the thermostat.

 

Sounds just like a heater core issue I worked on last year.

 

Did you just flush it like stated above, or did you have to replace the heater core?

 

Like beau and devil said just try flushing it first. Its pretty easy and there is good write ups online for this. If that doesn't work assuming that your blower motor is functioning as it should you'll have to rip apart the dash to get at the heater core. If you would shy away from the water pump/thermostat change then trust me the heater core aint much better.
Good luck

 

Matt,

With a 2001, you can use the climate control (see the link) to tell you the water temp. On my 99.5 V6, the water temp goes to 90C and stays there. If you're water temp is 90C and you have no heat, the stat is doing its job. Then a clogged heater core is about the only option.

If the water temp doesn't get to 90C, then start thinking stat.

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