Car overheating- What could it be?

[kepone]

I have a 04 b6 fwd 1.8t, all scheduled service has been done by the dealership on time. The car now has around 51,000 miles on it and it is beginning to overheat semi frequently.

Coolant levels are good, never low. When I am sitting in traffic my AC starts to get warm and then the engine temperature slowly starts creeping up. At first i thought it was just my AC and i already had that recharged.

Any ideas? What could it be?

[04QuattroTurbo]

Usual suspects, thermostat, fan switch, fan, coolant Temperature sensor/switch. With the engine temperature going up as you sit in traffic, I'll lean towards a thermostat.

[bwoy1981]

WOW! Z! Where have you been??? It may be your thermostat, mine was stuck in the open position and I was over-cooling.. check it out.

[kepone]

Usual suspects, thermostat, fan switch, fan, coolant Temperature sensor/switch. With the engine temperature going up as you sit in traffic, I'll lean towards a thermostat.

I just spoke to a service advisor from the local Audi dealership, he said it is most likely one of three things

1. Temperature sender
2. Relay
3. The cooling fan itself

The relay would obviously be the easiest to change, but how much of a job is it to change the fan and or temp sender?

How difficult to change the thermostat on our cars?

[dirtybrd]

You have to pull the intake manifold and maybe the alternator of you don't have swivel sockets.

[bwoy1981]

Z.. talk to this guy^^^^^ he did mine..lol.

[kepone]

You have to pull the intake manifold and maybe the alternator of you don't have swivel sockets.

I've not done that on a 1.8T before, how difficult is it? That is for changing the thermostat right?

What about the other items, temp sender, cooling fan?

[AudiA4Turbo22]

mine kept overheating today no matter what i did i found out my water pump died!

[05UltraSprt]

I've not done that on a 1.8T before, how difficult is it? That is for changing the thermostat right?

What about the other items, temp sender, cooling fan?

Thermostat is not a big deal... Like DirtyBird said, you really need to pull the alt. I found it to be a PIA to reach around it. IIRC it took about an hour.

The temp sensor was a pain only becasue my hand didn't fit in that area.

Can't help ya on the cooling fan.

Also, I had the same symptoms you are describing, which led me to change the above mentioned items, then I did the timing belt & water pump. As it turned out, my impeller was cracked in half so I wasn't getting any circulation.

[Affinitive]

AMB engine Thermostats are notorious for being the biggest POS ever. Piece of cake after you pull the Throttle housing and alternator. When you pull the thermostat, reach into the block to see if the water pump impeller is starting to spin on the pump shaft. This thermostat also has an electical connection on it. Don't worry, it's not a sensor or nothing, just a heater element in the stat that the ecm can use to force it all the open, should it need to. As for symptoms of a cracked impeller, you would get very little heat out of the heater core due to lack of circulation. Though at 51 K it would be a little early but not surprising so it's best to remove the stat when it's warm and reach in the block to see if the impeller spins. Sometimes they'll hold tight enough when cold but start to spin when warm/hot.

Being a B6 chassis, if the battery is disconected long enough, you'll have a traction control light on after reconnecting and steering angle sensor faults stored in the ABS module which will not clear until you drive the car and get some good steering wheel movement along with wheel speed signals.
Brace yourself, AMB thermostats are expensive. You'll see why when you get it. Also get the little o-ring for the coolant pipe which fits into the thermostat. When refilling, it's very crucial to loosen the bleeder plug on the coolant pipe on top of the intake.

C

[CO AVANT]

^^well put.

If you need a new water pump I have one with only 1500 miles on it. Perfect condition.

[kepone]

Thanks guys, this has been very helpful.

Is there any type of CEL or code thrown when there is a bad thermostat?

Also, has anyone here ever changed the cooling fan? can that be done with hand tools? I'm not with the car right now so I can't go check

[04QuattroTurbo]

Thanks guys, this has been very helpful.

Is there any type of CEL or code thrown when there is a bad thermostat?

Also, has anyone here ever changed the cooling fan? can that be done with hand tools? I'm not with the car right now so I can't go check

I've never tried it on an Audi, but for other cars it is a bolt on process, so yeah you can do it with hand tools, I suppose.

[kepone]

I've never tried it on an Audi, but for other cars it is a bolt on process, so yeah you can do it with hand tools, I suppose.

I'm sure the fan itself is a bolt on part, but if it's one thing ive learned about Audi's it's the process of getting all the other parts out of the way that sometimes requires more than basic tools haha

Unfortunately im in transition, moving from Orlando to Fort Lauderdale so i don't have access to any of my stuff

[dougyfresh]

The electric fan on the radiator? Good luck getting that out without moving the core support. There is very little room between the core support / radiator fans and the front of the engine / serpentine belt.