850 Temperature Gauge

Gentleman Mac · Post by **Gentleman Mac** » 19 Sep 2011, 21:04

Hey, guys. My temperature gauge on my dash (1995 854 168k) seems to be taking a long time getting to 3 o'clock, roughly 30 minutes, and then doesn't quite make it there. Sometimes at stops it will get there, but then slips down a bit after that. Is it time to replace something? Thanks, as always,
1995 854 168k
1998 v70 glt 166k

Post by **jblackburn** » 19 Sep 2011, 21:06

Time for a new thermostat!

Replace thermostat volvo 850 s70 v70 c70 or xc70

Get some PB Blaster and new thermostat housing bolts from the dealer - they'll likely strip out if it's never been replaced before.

Gentleman Mac · Post by **Gentleman Mac** » 19 Sep 2011, 21:17

Thanks!

Gentleman Mac · Post by **Gentleman Mac** » 19 Sep 2011, 21:23

Is there a preferred thermostat brand? Are the bolts only available from the dealer?

Gentleman Mac · Post by **Gentleman Mac** » 19 Sep 2011, 21:27

One more thing; why is it necessary to drain some of the coolant (and then replace it with the same drained stuff) as the link says to do? Just for my information,

Post by **jblackburn** » 19 Sep 2011, 21:42

You don't HAVE to drain the coolant; just pinch off the hoses from the expansion tank. If you haven't changed the coolant in the last 2 years, I'd do that at this time. Drain all of it from the lower radiator hose (just yank the hose; dont mess with the petcock), and the back of the engine block drain.

Thermostat brand - Wahler or Calorstat.

Post by **FlyingVolvo** » 19 Sep 2011, 21:44

You'll lose a little bit when you take off the thermostat housing. I never have drained mine before for a t-stat change, I just put a cloth around it when I pull off the top. I top up again with new coolant after.

As far as brands, any will do just fine. I would prefer the brands available on FCP or IPDUSA (I use Wahler). But I've also used the Duralast from Autozone with no problems.

Gentleman Mac · Post by **Gentleman Mac** » 19 Sep 2011, 21:47

Thanks, guys. Will do.

whoa · Post by **whoa** » 19 Sep 2011, 23:01

Don't skip the PB Blaster. And get the hard-to-get-to bolt out first (no need to antagonize it by pulling it's buddy before it). You don't really need an extra long torx bit, but you might need to loosen a bracket where the fuel lines run over the passenger side of the engine so that you can budge those lines a bit to get a straight shot at the bolt. Better to do that right away than have to deal with clearing enough space for vise-grips later.

And no need to tighten these bolts very hard. You're putting a cap on a soda bottle, not cranking down a head bolt... And use some anti-seize compound on the new bolts like you use with spark plugs.