jcman

Oh. Well, I guess doing the coolant temp sensor won't hurt but blink brought up the Crank Position Sensor CPS a few posts ago, I even threw a few cents in on that too regarding the start/stall problem.

acarney

Ah, ok! Didn't catch that "speed sensor" was the crank position sensor... Happen to know the part number on that? Something I could do without putting the car on a lift and just using jack stands?

jcman

Here's a good start but you have to check your VIN# they have other ones too, Audi C5 A6 Quattro 2.7T Engine Electrical Sensors Speed - 078906433A - Crankshaft Position Sensor - ES#2642846

Not that hard to replace, right rear side of engine in the trans bell.

jcman

It can be replaced from the top of the engine bay....lookie

acarney

And an update... Replaced the coolant temp sensor (green sensor pass rear of engine) after about an hour of fighting with how to get an adult hand into an area that was designed for a small malnourished child's hand and then fired it up. Started as strong as ever right away without even half a second of hesitation. Let's hope it wasn't a fluke... We'll see over the next couple days if it's a true fix or just randomness. I'm SLIGHTLY worried I have oil in my coolant though (and I know that's a rather bad sign)

There was about four drops of oil or blackish coolant right around the rim of the pipe where the sensor mates up against it... Not sure if it was grim from years of crap or maybe something coming off the o-ring gasket or what, but the rest of the coolant in there looked great and in the expansion tank it looks beautiful. I don't see any smoke out the exhaust, it doesn't run rough, or anything. I had an oil analysis done in June and they said it looked great and didn't find anything out of the ordinary. I'll have to keep an eye on this though...