I find that the gauge isn't very accurate. Once the car warms up, my scangauge stays solidly at 840 while the volvo gauge looks 900ish.

Yeah, what everybody else said.
For what it's worth, I took my switch apart and cleaned out the fuzz and grime from the contacts and it works great. If you're mechanically inclined it isn't hard and it's been fine for over 2 years now.

I could be wrong, but I would imagine that if you patch it, you'd need to patch on the opposite side to balance it, as the patch itself might be enough to throw things off once you get the car going fast enough.

You can always pick up the parts from an 850 in a junkyard, they're the same parts for the fan and the resistor, it' ll probably cost you 30 to 50 bucks. I just picked up a working fan from a 97 850 that had a manufacture date of 2008: cost me 18 bucks and will probably last years.

Sway bar links. they make a noise that seems to come from somewhere else.
I changed them and bad noises went away.
Just sayin'.

Man, I feel your pain; that happens on every job that I've done.
The directions will read "remove so and so screw" and that little step takes 2 hours because of any number of reasons.
much cursing has ensued.

You probably have water under the spark plug boots. that will mess things up big time and won't evaporate for a while.

My mileage improved by at least 7 mpg when I fixed my airbox thermostat.
I'm not sure if your model has that, but it's worth a look.

check out this post:

https://www.matthewsvolvosite.com/forums ... php?t=8830

Hi, I meant to reply to this a while ago but forgot. Once I did the oil change I was able to actually experience what lifter noise sounds like for a few seconds before it went away, and it was WAY louder than the injector noise. It actually reminded me of an old propeller airplane engine starting up...

I wedged a panel removing tool in there and put a pipe against it and hit that with another pipe and somehow that worked.
I wish I'd had one of those short crowbars.
Be prepared to catch the fluid that will come spilling out,