jibberjive

Wow man, every one of those jobs is harder than replacing the EGT on the passenger side. It took me less than an hour my first time on the EGT. Sounds like you gave it quite the restoration/upgrade!

complacentsee

Yeah, if that rusted heat shield bolt hadn't stripped it would have been a breaze. Assuming the sensor wasn't rusted in.

complacentsee

Passenger side is one of the easiest repairs, it's the damn driver's side heat shield shield that ruined this one for me. But yeah, a bit of an overhaul. Now all I need to do is find a place I can call my shop for a while. Find a wrecked 6mt. Save up for a couple more months for some turbo option. (unless the wrecked one I pick up has k04s) Then again I would hate to do all the work and still want RS6s. I suppose if I got one with k04s I could sell the full kit and have abit towards rods or something.

RolledMySTi

Sounds like you had a fun weekend.

complacentsee

**** yeah, loved every minute of it besides the driveshaft issue.

DD (CA)

More info here...

http://en.wikipedia.org/wiki/Conformal_coating

Quickly, it's used to prevent moisture / dust / contamination onto pcb. Pretty typical for under hood auto electronics.

did you catch the mfr of the part btw? Bosch?

DD

complacentsee

the EGTs are bosch.. Or did you mean the PCB itself? I had never seen a still semi-liquid form of that, or soo much being used.. Then again, mV sensing electronics under an engine bay. Probably is also used as a sort of heat sink to keep the electronics temperature more even and stable.

I was under the impressure all the engine electronics (with the exception of the hitachi MAF) were bosch due to a bid package or something... Who knows though since VAG seems to have stuck with them over the years.

complacentsee

Converted my bank 1 egt to a universal keying tonight. Bank 2 connection to B1 EGT resulted in working EGT reading. Bank 1 Connection was free hanging since that one requires modifiing the electrical harness connector and I was to lazy/ had convered enough angles to convince myself it is still a failed sensor.

Well $50 well spent for us to never try that fix again.

megafreakindeth

i would think the codes for egts are due to the thing that goes in the exhaust breaking. not the circut board, ingenious repair though. however the egt works (probably X temp = Y resistance). through the life of getting super hot and cold over and over as youre rollin down the highway the sensor element either gets worn out(egt high resistance) or breaks (short to ground/power).

i have a 2000 so replacing the pass side is stupid easy and the dr side requires a specific wrench and crows foot.

if you said that the newer egt had more sodler joints than mabye it really is a circut board problem which would be so cool as you can probably just open em up and resolder the joints

ihave a bad one with high resistance, i also bought a 50 dollar replacement used but im gonna cut up my old one now and take a look. could be onto something. customers dont usually want to shell out for the 2hr labor and 400 dollar sensor

complacentsee

I made a guess that the issue was in the heat cycling of the circuit board and semiconductors. I was at the time a bit more convinced that the electonics failure would be more common than a probe failure. The probe is just a theromo couple. So, you have a reference temperature. A fixed current source. And then 2 probably rather exotic metals joined in the inside of the the tip of the copper looking probe end. Then you "just" measure the milivolt-microvolt changes in temperature.
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All this while the electonics sit at some god awful engine bay temperature. I can see why they would have avoided solder, as that change the voltages slightly. But, our probes only work on such a limited range anyway.. Who knows.

Anyway the egt (or so I've read) outputs a PWM signal, and the ECU only cares about the DC value of it. Apparently, you can just modifiy the wiring harness and tap the signal of a working EGT. I would imagine the responce time of the EGTs are slightly increased, and you are going to feed inaccurate signals to one bank. Hard to tell if this is any safer than a faulty one.