Here's something you may not have seen before - coolant filter
 

I installed a Magnefine filter on the return line to the coolant reservoir on my 2000 Volvo V40. Why? Why not.

Just uninstalled it after 9,500 miles. Here's what was in it - a fair amount of muddy debris - though it isn't that apparent from the pics. And yes, Magnefine filters are serviceable though they really don't want you to know that.

https://volvoforums.com/forum/member...ter-1-6598.jpg

https://volvoforums.com/forum/member...ter-2-6599.jpg

wow... interesting ......how would this get so dirty ? just old coolant ? i can't wait to paw over my buddies s40

I'm guessing the car had the original coolant when I bought it a year ago - i.e 12 years old coolant. The sludge seen in the pics is mostly non-magnetic so may be from the factory block casting process.

One of my crackpot theories is that every fluid in an automobile should be filtered, including the coolant. This car has an easy way to do that because of the 3/8" hose that returns to the coolant reservoir.

so should i look for a flimsy hose or rusted pinch clip........you know what Im just going to tell him this has to be done asap with this info .Its his wife's S40 its summer, its getting hot and they just bought it used ....thanks migbro

No, this is not necessary on any car, though it doesn't hurt. Just my little experiment.

YES ! i was talking about his wife's volvo 2002 S40.....who knows when the last time the coolant was changed on this s40 or if ever changed like YOURS. But it wouldn't hurt them at all for 30$-40$buks ..thats why i was asking...... THANk YOU MIGBRO good luck and happy driving!!!