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Coolant drip from mid O2 sensor connector

Discussion in 'LR4' started by Lgibson, May 3, 2021.

  1. Lgibson

    Lgibson Full Access Member

    Likes Received:
    Dec 25, 2014
    91C5CF87-A3EA-440A-80CE-D977B46B9A7D.jpeg B52CE340-B146-4109-9CD9-CF01CAF26B7B.jpeg Just finishing up with the LCA replacement and I notice a drop of moisture back by the center diff. Tasted it...definitely ethlene glycol. Looking up for the source I notice the connector for the middle O2 sensor is damp. The front of the LR was elevated and the driveway is inclined a bit so the fluid might have traveled way back there. The surrounding harness feels dry and the coolant reservoir is full. I’m well aware of the dreaded catastrophic crossover pipe leak(s) and we are at 6 years and 54k miles.

    How should I proceed?
  2. jlglr4

    jlglr4 Full Access Member

    Likes Received:
    Mar 19, 2019
    Northern California
    You are probably due to change the crossovers anyway, but I’d want to try to find the leak first if I could so if there are any additional hoses to be replaced, you know in advance. You can try sticking a boroscope down into the valley next to the oil filter and look for fluid, and maybe feel around the rear crossover with your hand.
    There are several hoses that run off the passenger side of the rear crossover and into the heating system. Some go into the heater core in the front cabin, and then some run down along the bottom of the passenger side of the car to the rear wheel arch and into the aux heating unit in the rear cabin.

    Maybe put a pressure tester on it if you have one at your disposal. And/or some UV dye - make sure you get the stuff that is dexcool compatible.

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