!&%*! Changed coolant expansion tank and now Check Engine Light?
 

The topic says it all. I noticed some serious dexcool leaking in the driveway under my '97 A8 Quattro. Checking under the hood I noticed that the tank had separated where it is molded/pressed together. I also saw that the small feed to the tank on the top was cracked... all the way around!

My hoses and clamps looked in good shape, so I just yanked and replaced the tank. I added in the dexcool, turned the car over, and then the check engine light came on. I think I have the sensor on the right way; it does have an idiot plug/groove and seems to snap all the way in (that's the only thing I could think of that would cause the problem.)

Any ideas? Any neighboring connections are good; I don't think I knocked anything loose there.

Possibly a DTC due to low pressure in coolant? or detetected disconnection of sensor.

I did the quick change...
 

Is it safe to drive it like it is?

Could be, but...
 

Pressure seemed to build-up OK when I let the car run a bit. The car was sitting idle for 4-5 days before I did the swap, so there was little/no pressure build up as it was sitting.

That's all it took?
 

You swapped it out according to that procedure and it went from having errors to being fine? Maybe it is detecting air in the lines?

The tank was nearly dry when I swapped it out because of where it was cracked and how it was leaking.

I'm cheap...
 

I've been putting off buying it. That and I don't have a Windows box anymore; I'm purely a Mac and Sun/Solaris geek at the house.

I'll abuse someone in the locator. The car sounds fine and all the connections seem nice and tight (no leaks so far, and I did let it run enough to have coolant pump through and come into the tank from the top.)

Audi Coolant? I thought it took standard dexcool???

I don't take the help w/ a grain of salt...
 

That is what my wife is for. Hommemade cannolis. Good thing she doesn't read the forum :)

Found the PM Article
 

<a href="http://popularmechanics.com/popmech/auto3/9903AUSMM.html">PM article</a> -- looks like I snagged the right stuff, or at least stuff that I'm confident won't horribly destroy things.

I need help with my laptop. Can I shoot you an email?