2004 XC70 Manual says coolant flush not needed

Magyar1125 · Post by **Magyar1125** » 04 May 2017, 05:06

I took over servicing my 2004 XC70 about 6 years ago. Now at 230,000 I figured it was time to do a coolant flush. I took out the manual and it says: "Coolant replacement should not be necessary." At this mileage I believe it IS necessary. I went to take out the thermostat to run flush through the system and it is extremely difficult to get at. I want to replace the thermostat and the sensor since when it is cold out the mileage drops 3-5 mpg. Volvo parts dealers say that the whole unit needs to be replaced. Is this as crazy as it seems?

Post by **Botbasher** » 04 May 2017, 06:37

As anyone with a 00-03 AW55-50SN trans will tell you... THE BOOK IS WRONG!!! The factory service intervals (if any!!! Trans Fluid) need to be disguarded and you should follow well known intervals for critical service. When was the last time it was changed?? With 230 on the clock, you should only have about 30-50k on this timing belt and therefore on the coolant if the previous servicer did a belt/pump service at 90-100k intervals. Might want to check your records as to when the last change was done.

The t-stat housing is a little difficult to get at, but it can be done with the removal of a couple of covers and a swivel on the ratchet and once the housing is out, the sensor is right there too. I did mine in under an hour and that included lifting the car to drain a bit out of the rad (you might be flushing, so no worries here).

Good Luck!

K "flushed" S

Post by **oragex** » 04 May 2017, 08:11

This should fit but double check. Look close to check if the bleed pin is right at the top as it sits before installing it http://www.ebay.com/itm/Beck-Arnley-143 ... oD&vxp=mtr

To get the lower stat bolt the p/s pumps needs tossed and you need a wobble 1/4" socket. you can also only undo the two bolts to split the housing open

I think I've used Prestone with ethylene glycol if I remember, mixed 50/50 with distilled water. The lower radiator peck is brittle plastic and I think needs an allen key: don't force on and just lightly tighten back. if stuck can undo the lower radiator hose. there is also a drain valve at the rear of the engine hard to see. I've also disconnected the hoses to the fire wall and flushed the heater core alone.