01 V70 thermostat deposits?

bremic · Post by **bremic** » 27 Jan 2013, 11:56

01 V70 FWD, 130k. MN Winter, been a little chilly here as of late (-15.) Recently received the P0116 coolant sensor CEL. Temp gauge hasn't been up to the halfway point since it got really cold out. Ok, new thermostat and OEM temp sensor and a drain. Previous owner did pump 18 months ago with new fluid.

Took out the old therm and sensor and saw black deposits that I have never seen before. Inside of the thermostat body looks good. Fluid that came out wasn't dirty. Are the deposits anything to be concerned about?

2nd question, the fluid that came out looked a bit like diluted apple juice so guessing it's probably Zerex G05? Have always used the Volvo OEM coolant (what's $10-$15 over 30k miles) regardless of vehicle (740,940,960,S70) and plan and refilling with Volvo.

Thanks!

: Black Thermostat deposits?; Volvo V70 Thermostat Small.jpg (210.53 KiB) Viewed 289 times

bremic · Post by **bremic** » 29 Jan 2013, 19:31

Update...

New thermostat and temp sensor are in, coolant drained and filled with Volvo blue. Everything works well, temp goes to halfway rather quickly and stays there. Only had to top off once with about half an overflow tank. Nice to have heat again! Just in time for some more really cold air.

Boiled the old thermostat and it opened about 8-12 degrees sooner than it should of. Boiling did not remove any of the black deposits, still no idea why the deposits are there on the old therm & sensor.