joeyvaz

I've searched through 10 pages of forum archives, so please bare with me. I have a 2001 Allroad 2.7t. I have a coolant leak that is coming from a hose that has a plastic elbow on it. The elbow seems to connect to the rear of the engine almost directly above the passenger side o2 sensor. This hose seems to go to the heater core thru the firewall on the other end.

Has anyone else experienced this problem? If so, any tips on changing the part, part#, cost, etc.

joeyvaz

In case anyone was wondering, it was the o ring on the coolant temp sensor. Swapped in a new one and all seems fine.

quickaudi:STFA

excellent!

Peter Badore

The coolant temp sensor can also leak across the pins short circuiting them and causing a false signal the ECU.

joeyvaz

i think that happened to mine. I'm getting a code and having cold start issues, but temp gauge is working. I have a new sensor being delivered tomorrow. Should clear things up.

Joe

quickaudi:STFA

what code?

joeyvaz

PO117 Engine Coolant Temp.Senor (G62): Signal too low

Peter Badore

My problem was that a DTC wasn't set. I think that the coolant that leaked across the sensor pins sent
an incorrect reading to the engine controller indicating a warmed up engine when in fact engine
was actually cold. The NTC sensor was probably fooled by the low resistance of the coolant shorting the sensor pins.

joeyvaz

I swapped the CTS today. Sure enough, when I disconnected the old one, there was coolant pooled up in there due to the o ring leaking. I sprayed compressed air into the connector to dry it off since it was wet too. Around 20 miles and the code hasn't reappeared. Hopefully my next cold start will be uneventful also.

Joe

quickaudi:STFA

sweet! you did put a new o-ring in there, right?