upstream O2 sensor - is this coolant? - 01 V70XC

saq · Post by **saq** » 15 Nov 2025, 15:01

Just replaced the upstream O2 sensor on the 2001 V70XC (because of engine code). Pulled it out an am a little unsure of the look of the sensor - could just be "this is what they look like after 200k miles" or could be something wrong (though it doesn't seem to be "gunky" enough for coolant leak).

: 01v70o2-tip.jpg (67.98 KiB) Viewed 216 times

: 01v70o2-side.jpg (59.4 KiB) Viewed 216 times

I am a bit more concerned because this car was giving me lots of misfires at startup over the summer, but pulling the car keys off of all my other keys (actually splitting it into 3 more manageable rings) made that and the "no throttle response" issue go away, so I don't think it was from a damaged head gasket. Oil also shows no signs of coolant contamination (and vise-versa), and while I did have to top up the coolant a bit recently the cap wasn't sealed so may have just evaporated off.
Seems closer to silicone really, but I haven't used any silicone on the car.

Post by **jonesg** » 15 Nov 2025, 20:03

mine looked like that at 230K miles, it still does.

Post by **abscate** » 16 Nov 2025, 01:54

Absolutely normal for an in use OXS

saq · Post by **saq** » 16 Nov 2025, 06:40

Ah good, thank you - many pictures I see out there must be of much younger sensors.