Dropped the car off this morning.. outlook: not good..
 

Walked in the dealer and kindly greeted the gentleman at the desk. He started keying in my information and as he was, i looked at a hot S4 sitting on the other side of the delivery area. I jokingly said: 'and if i doesn't work, i'll take the red S4' to which he replied: 'well it's lookin like you might be driving that S4 soon.'


i looked back at him with some level of concern showing on my face, 'you don't think you can fix it?'

to which he replied 'we can try to see if we can fix it, but we aren't going to inherit someone else's problems, we're going to have to start from square one'

i told him 'you gotta do what ya gotta do!' with a kind smile on my face.

so: here they go, testing the thermostat (already been done), testing the temp sensor (already been done), checking the water pump (already been done)... he quoted me $180 to start, said it would go from there.


what a wonderful start to my thursday.

link to original problem?

so many links...

Here's three...
 

<a href="https://forums.audiworld.com/tt/msgs/1778954.phtml">Newest, most recent post</a>

<a href="https://forums.audiworld.com/tt/msgs/1777555.phtml">Middle timeline somewhere</a>

<a href="https://forums.audiworld.com/tt/msgs/1775228.phtml">Older Post</a>

so have you tried another 3rd or 4th green top
 

something you can do on your own is flush the system. run a hose through it after you empty all of the coolant. then take off as many hoses as possible, check for problems and re-install. it's unlikely but it could be clogged somewhere. it's very unlikely that the radiator is clogged if it still has pretty pink coolant in it. this is more of a ruling out process that is nearly free. also might dislodge the plastic from the wp if any was missed...

sorry man, i hate perpetual problems. and i hate the dealer even more.

and the way it's eratically hopping around sounds like a green top issues. also sounds like a thermostat even though you've had that checked sounds like it's wacky and sporadic.

yeah i thought about it possibly being a t-stat
 

but the way it sometimes jumps between 98 and 121 instantly, that hints to me that it isn't a t-stat.

yeah, that sounds electronic to me.
 

and since it's doing it on HVAC also and not just cluster seems it is somewhere in the measurement system.

try another green top unless you have already.

i imagine they will today...
 

'measurement system'

i just pray that isn't an ECU component, because not only is mine chipped, but i just KNOW that they will want to replace the whole unit and charge me a grand for it.

i bet it's not the ECU
 

if it were that wacky you'd be having other problems as well.

maybe there will be a really talented tech there, at least we can dream.

one more thing you could do to rule out the thermostat is get an IR temp gun (amazon.com for $30), and when it spikes up like it does, shoot the area where the temp sensor is mounted. that will tell you if the coolant has spiked or not when compared to HVAC reading (i don't think it is though).

already did that actually.
 

and the laser temp gun reads like 90-100, not 121...