Overheating

[Thepooj]

Soooo...after months of being frustrated with this issue I toss it out there to see what you infinitely wiser S4 folk have to say. Every couple of months my car overheats (meaning the gauge goes past the mid point, at times dangerously so). I schedule an appointment with a mechanic, then as i'm driving to the mechanic the problem goes away. And stays away for months at a time. Then it will do it again. A few months ago I did a coolant flush, I have replaced the reservoir cap and CTS (cheap fixes first I always say). But the problem, in its own special Audi way, persists. Any thoughts? If I had a small (and I mean not even really there) leak in my coolant reservoir would that change the pressurization of the coolant system? I should also add that my coolant levels have been pretty steady.
Today's episode involved me driving for an extended period of time and whenever I was stuck in heavy traffic the gauge would start to move over, then when driving the gauge would edge back towards the middle.
Thoughts?

Also, I'm looking for a 10mm bolt for an inlet pipe...my car ate mine. Best place to find such a thing?

2001.0 Audi S4
Stage 2+

[The_Jerbel]

Re: Overheating

Soooo...after months of being frustrated with this issue I toss it out there to see what you infinitely wiser S4 folk have to say. Every couple of months my car overheats (meaning the gauge goes past the mid point, at times dangerously so). I schedule an appointment with a mechanic, then as i'm driving to the mechanic the problem goes away. And stays away for months at a time. Then it will do it again. A few months ago I did a coolant flush, I have replaced the reservoir cap and CTS (cheap fixes first I always say). But the problem, in its own special Audi way, persists. Any thoughts? If I had a small (and I mean not even really there) leak in my coolant reservoir would that change the pressurization of the coolant system? I should also add that my coolant levels have been pretty steady.
Today's episode involved me driving for an extended period of time and whenever I was stuck in heavy traffic the gauge would start to move over, then when driving the gauge would edge back towards the middle.
Thoughts?

It's possible that you're T-stat is intermittently sticking. Modern T-stats are designed to fail open 98% of the time, but every now and then one will stick closed once in a blue moon...

Also, I'm looking for a 10mm bolt for an inlet pipe...my car ate mine. Best place to find such a thing?

2001.0 Audi S4
Stage 2+

The best place to find one of those is probably in my garage.