1999 V70 Check transmission, Not sure I trust the mechanic

[oragex]

Recently, the check engine light and and the flashing arrow indicating a transmission issue began. When I took the car into a mechanic "Not one I had been to before" They ran a diagnostic, though a few things seemed iffy.

I would stick with this for now, that is why you went to the garage, the rest - their findings - may or may not be true but many garages are 'willing' to make money - same goes for the Volvo dealer when they see an old car

Did you recently had a long ride perhaps driving through mountain areas with lots of uphill? If so, the old transmission fluid may have overheated and it's no more efficient. Replacing even part of the fluid can't hurt, you'll need a garage to undo the return hose, most garages can do that. The clip may break so it's good to purchase first a new one with seals from Volvo ($30?). With the fluid this job should not be more than $100, it's simpler than an engine oil change. As mentioned no power flush (many garages do this)

Keep in mind, the transmission may have other issues. I remember some models had a problem with a seal failure allowing coolant to leak inside the transmission, a coolant check for oil contamination would be a good idea just to be safe (just check inside the coolant reservoir)

The thermostat doesn't give a temperature, rather the coolant sensor does so. Here's how to check the thermostat Frankly, if the engine warms up quickly and the gas mileage is fine, leave it like this for now.

[readallthebooks]

there should be a few quality volvo shops in santa cruz. if not the greater bay area has lots of reputable high quality shops that work on volvos. take it somewhere else!

[wizechatmgr]

Other option would be to attempt to seek any local clubs. You say you're a college student - do they have an Auto program at your school? If so, they may also be a great resource as I've seen some that charge only for parts and others that charge very little for labor.

[FLXC90]

First, just address the transmission issue. The fluid replacement by drain and fill may be all you need. Drive it for a few hundred miles to determine results. If it is almost right, consider adding a solvent like seafoam trans-tune, and repeat drain and fill procedure. You'll spend 100-200 bucks and know if your car is a keeper.