My daughter took our 2000 S40 for a road trip (CT to Pittsburgh and back) and noted that on several occasions the transmission would downshift from 5th to 4th and not up-shift for 2-3 minutes even after backing off the gas. A couple other times it didn't want to up-shift from 2nd to 3rd when accelerating. Each time happened after the car had been on the road for a long time. I won't get a change to check the transmission fluid level (and color) until this weekend, when I am thinking of doing a drain and fill.

How many quarts of Dextron should a drain and fill take?? (I see FCP offers Idemitsu #1161540 for $6 a quart - also any opinions on their product)?

Anything else to look into (ie PNP or gear selector switch etc)?

 

I bought 2 plastic semi-clear paint buckets from Ace with graduated fluid quantity markings and simply replaced the amount that drained into one bucket with the exact same amount of clean fluid in the other bucket. But I did not write the amounts down anywhere. I have got to remember to take a pic or something next time.

IIRC, you only get about 50% old fluid out from the drain. To get most of it you would need to drain and fill about 4 times with a bit of driving between each drain/fill. 2 times have worked well for my daughters 2001.

 

So I finally got around to checking the fluid - seems fine, a nice reddish brown with no gritty feel and the level seems normal (I may recheck again from inside the garage and do a proper cold/warm). What I did notice on my test drive was the car had some hesitation/surging on WOT going up a hill so I'm thinking I may be due to swap out coil packs (plugs were done during the summer). No CEL though... I guess I need to do a longer test drive tomorrow.